48V 1000 W · 160 N·m · 1,200 Wh · 20 mph · 375 lb payload · 78.7 lb · Gray $1,999 · Camo $2,099 · verified September 26, 2026
Quick Answer — The Eunorau FAT-HD 1.0 Pro, sold as the Hunter X7, is a fat-tire e-bike with a 1000 W, 160 N·m mid-drive and 1,200 Wh from $1,999. On one charge a 180 lb rider gets about 66 miles at 15 mph on the throttle, on flat pavement, and about 49 at its 20 mph top speed.
Its 375 lb payload is you plus what you carry; the 78.7 lb bike sits outside that figure. At 1000 W it sits outside the e-bike definition in the 44 states that draw a 750 W line and inside it in four jurisdictions, so the class section is the one to read before you plan a route.
Gray at $1,999 or Camo at $2,099, both orderable on September 26, 2026. It ships to the lower 48 at no charge, and a warranty claim goes through us, never a ticket queue at the factory.
Buy the Gray FAT-HD — $1,999Takeaway
- About 66 miles at 15 mph on the throttle, and past 100 pedaling easily. A 180 lb rider on flat pavement from the one 1,200 Wh pack; the range tables cover hills, load and the cold.
- Eunorau's "up to 60 miles" is a steady 16.8 mph on the throttle. Sixty miles from 1,200 Wh is 20.0 Wh a mile, and the model shows the ride that spends it at that rate.
- The 375 lb payload is you and your gear. Eunorau counts the rider and the load in it, so the 78.7 lb bike is never subtracted (the payload section).
- Tall riders: check the saddle. From 5'4" to 5'9" the saddle reaches the fit formula's height for 96 of 100 riders or more; at 6'0" it is 52 of 100, and at 6'2" 14 (the fit tables).
- Inside the e-bike definition in four jurisdictions at its 20 mph setting: the District of Columbia, Montana, Oregon and Rhode Island. In 44 others the 1000 W rating is above the definition's 750 W line (the class section).
- The independent review AI engines cite for this model rode a 2019 build: 15.6 Ah, 28 mph and mechanical brakes. The generations table sets it beside today's 25 Ah, 20 mph and hydraulic discs.
What's on this page
Twenty-four sections, in the order the buying decision runs: what the bike is for, how far it goes, whether it fits, where it counts as a bicycle, what owning it involves, and the verdict. Each link jumps to its section.
- Who the FAT-HD 1.0 Pro is for
- How we verified this Eunorau FAT-HD 1.0 Pro review
- Eunorau FAT-HD 1.0 Pro specifications
- The FAT-HD the 2019 review describes
- How far it goes, gear by gear
- What the 375 lb payload covers
- Will it fit you?
- The Mercer fit test
- 1000 watts, 20 mph, and all 51 jurisdictions
- What "Class 2, unlockable" asks of you
- Cadence sensing, and what it feels like
- Charging, against the charger in the box
- Which of Eunorau's figures this review uses
- Has it been recalled?
- Is it UL certified?
- The warranty, and who files the claim
- Buying it from us
- The honest ledger
- Who should buy it
- Before you buy: the checklist
- Limitations of this review
- The source register
- Frequently asked questions
- The bottom line
Who the FAT-HD 1.0 Pro is for
The Camo build as Eunorau photographed it, on a studio sweep we added around the photograph for the card. The 1,200 Wh and the $1,999 starting price are listed figures; the 66 miles is computed below.

Eunorau's own photograph of the Gray build. The rack, the fenders, the lights and the kickstand all come on the bike.
Buy it if your ride starts where the pavement ends and your job is carrying weight a long way: a stand, a cooler, a day's gear, down a fire road and back. The case rests on two figures, 1,200 watt-hours and a 375 lb payload, and on a mid-drive that climbs through the gears.

The motor sits at the cranks and turns the 46T chainring, so every one of the seven rear cogs changes what it costs to climb.
Gearing is where a mid-drive earns its keep. Eunorau names the motor as a Bafang M615 with "160Nm of cadence-sensing assist", and it drives the chain: on an 8% grade at 8 mph the 28T cog costs 85 Wh a mile against 224 in the 12T (the gear tables). A motor in the rear hub gets one ratio for every hill; this one gets seven.
Eunorau tags it "Hunting & Fishing", and the Camo finish is a $100 option on the same machine. The features that suit it to a hunt (fat tires, hydraulic brakes, the rack, a big pack) suit any long, loose and loaded ride.
If your riding is one of two other jobs, look elsewhere in our range. For singletrack, the SPECTER-ST 2.0 carries 140 mm of fork travel and a torque-sensing M620 for $2,549, and our SPECTER-ST 2.0 review prices its range and fit. For a daily commute on public paths, a 500 W machine such as the Defender sits under the 750 W line the class section turns on.
1000 W Bafang M615 · 160 N·m · 1,200 Wh · 375 lb payload · Kenda 26 × 4.0. The Camo costs $2,099 and the Gray $1,999; shipping to the contiguous states costs nothing, and we handle any warranty claim with Eunorau.
Buy the Camo FAT-HD — $2,099How we verified this Eunorau FAT-HD 1.0 Pro review
Every bike specification here is Eunorau's own, verified on September 26, 2026 against its product page and its product record, and recomputed wherever arithmetic enters. Where Eunorau prints a figure two ways, both appear and the one used is named.
The range and fit models close their own sections with the formula and every input (range, fit); the jurisdiction screen, the recall screen and our store terms are items 5 to 7 of the Limitations. Each legal statement carries a link to the provision behind it.
Redtail sells this bike, and the honest ledger lists who it suits worse. The author is Milad Ghobadibeygvand, BScN (Western University, 2014). Corrections go to corrections@redtailebikes.com.
Eunorau FAT-HD 1.0 Pro specifications
Every row is Eunorau's published figure, read September 26, 2026; where Eunorau prints a figure two ways, the conflicts table shows both.
| Specification | Published figure |
|---|---|
| Price | $1,999 Gray · $2,099 Camo |
| Motor | 48V 1000 W Bafang M615 mid-drive, 160 N·m |
| Pedal assist | cadence sensing, levels 0 to 5 |
| Battery | 48V 25 Ah — 1,200 Wh (our arithmetic: 48 × 25) |
| Range | "Up to 60 Miles" |
| Maximum speed | 20 mph, "Class 2 Speed limited Unlockable" |
| Payload | 375 lb of rider and cargo |
| Weight | 78.7 lb (35.7 kg) |
| Rider height | 5'7"–6'4" |
| Frame | 6061 aluminum, one size |
| Fork | RST Guide, 100 mm travel |
| Drivetrain | Shimano 7-speed, 12–28T; 46T chainring with guard; 170 mm forged alloy cranks |
| Brakes | hydraulic discs, 180 mm front and 160 mm rear, motor cutoff in the levers |
| Tires | Kenda 26 × 4.0 |
| Display and throttle | L183 LCD; thumb throttle |
| Charger | US-standard 2.0 A smart charger |
| Lights, rack, fenders | LED headlight, taillight, rear rack and fenders, all fitted |
| Saddle | 33.9 to 42.5 in from the ground |

Eunorau's geometry diagram and table. The 30.3-inch standover (G) and the 12.6-inch bracket height (E) feed the fit section.
The FAT-HD the 2019 review describes
The independent review the AI engines cited for this model on September 26, 2026 is Electric Bike Review's, published March 19, 2019; its own specification block reads "Model Year: 2019". Eunorau's product record for the FAT-HD dates from 2017, and the machine behind that address has changed while the address stayed.
| Today | 2019 review | |
|---|---|---|
| Price | $1,999 Gray · $2,099 Camo | $2,399 |
| Battery | 48V 25 Ah, 1,200 Wh | 48V 15.6 Ah, 748.8 Wh |
| Top speed | 20 mph, unlockable | 28 mph |
| Class printed | Class 2 | "Moped or Motorcycle (Class 4)" |
| Weight | 78.7 lb | 62 lb |
| Brakes | hydraulic, 180 / 160 mm | Promax mechanical, 160 mm rotors |
| Display | L183 LCD | APT 500c |
| Throttle | thumb | trigger |
"Today" is Eunorau's product page, September 26, 2026. The 2019 column is Electric Bike Review's labeled specification fields, read the same day.
The pack grew twice. Eunorau's own page says the battery went "from 16.5Ah to a massive 25Ah at no extra cost", and the 2019 test rode a 15.6 Ah pack; 1,200 Wh is 60% more energy than the 748.8 Wh that review weighed.
Heavier and slower on paper. Today's 20 mph setting is the one Eunorau labels Class 2, and the bike weighs 16.7 lb more than the 2019 build, with a pack 451 Wh larger and hydraulic brakes where that build had mechanical ones.

The Camo build, the same machine as the Gray under a different finish.
Every figure in the "Today" column was read from Eunorau's product page on September 26, 2026. Gray here, or the Camo version for $2,099; delivery is free across the continental US.
Buy the 25 Ah build — $1,999How far the FAT-HD 1.0 Pro goes: your range, gear by gear
A 180 lb rider on flat pavement gets about 66 miles from the 1,200 Wh pack at 15 mph on the throttle, and about 49 at the 20 mph top speed. Climb 8% at 8 mph in the 28T cog and the pack lasts 14 miles on the throttle; in the 12T it lasts 5.
Your own ride in three steps:
- Find the speed you hold and how hard you pedal in the first two tables.
- Add about 149 to 185 Wh for each 1,000 feet of climbing, and climb in the large cogs (the gear tables).
- Adjust for your weight and the day's temperature, then plan on 85% of the result, the share Eunorau's charging advice leaves in use.
Every figure is one steady ride priced from Bafang's published M615 figures, the 46T chainring and 12–28T cogs Eunorau lists, fat-bike tires measured on a drum and a power model checked against riders on a road. The last subsection shows the formula, every input and one ride worked from the wheel back to the pack.
How much range do you lose at higher speed?
About a quarter from 15 mph to 20: the pack that covers 66 miles at 15 mph covers 49 at 20, 26% fewer. Drag climbs with the square of your speed, and the power to push through it with the cube, so the last few miles an hour cost the most.
| Speed, flat | Cheapest gear (chainring rpm) | Per mile | Full charge | With 15% kept |
|---|---|---|---|---|
| 8 mph | 28T (57) | 12.7 Wh | 95 mi | 81 mi |
| 10 mph | 28T (72) | 13.8 Wh | 87 mi | 74 mi |
| 12 mph | 28T (86) | 15.3 Wh | 79 mi | 67 mi |
| 14 mph | 28T (100) | 17.1 Wh | 70 mi | 60 mi |
| 15 mph | 28T (108) | 18.1 Wh | 66 mi | 56 mi |
| 16 mph | 28T (115) | 19.2 Wh | 63 mi | 53 mi |
| 18 mph | 28T (129) | 21.6 Wh | 56 mi | 47 mi |
| 20 mph | 28T (144) | 24.4 Wh | 49 mi | 42 mi |
Throttle only, flat pavement, a 180 lb rider on a 77 °F day; the planning column keeps back 15% of the pack, the high end of the 10 to 15% Eunorau's FAQ says to recharge at. The gear is the cog in which the motor spends least at that speed, with the chainring's rpm beside it.
Pedal easily and the 15 mph ride runs past 100 miles. Seventy-five watts of your own, an easy effort, would carry this 78.7 lb bike about 8 mph with no motor at all; 150 W carries it about 13.
| Speed, flat | Throttle only | Easy pedaling (75 W) | Steady pedaling (150 W) |
|---|---|---|---|
| 12 mph | 79 mi | 100+ mi | legs alone |
| 14 mph | 70 mi | 100+ mi | 100+ mi |
| 15 mph | 66 mi | 100+ mi | 100+ mi |
| 16 mph | 63 mi | 89 mi | 100+ mi |
| 18 mph | 56 mi | 71 mi | 100+ mi |
| 20 mph | 49 mi | 57 mi | 77 mi |
Full-charge miles from the 1,200 Wh pack for a 180 lb rider on flat pavement. "Legs alone" marks a speed your own watts already hold, so the motor adds nothing. Past 100 miles the table stops counting; a stop or a headwind settles the day long before.
The pedaling columns follow the watts you put in. Eunorau's assist levels, 0 to 5, set how much the controller adds, so read the row for your speed and the effort you actually ride at.
Your speed and effort give you the row; the hill, weight and cold tables below adjust it. Gray at $1,999, Camo at $2,099, and delivery to the 48 contiguous states is free.
Buy the 1,200 Wh FAT-HDWhich gear saves the most battery?
On the flat, the largest cog: at 15 mph the 28T costs the least, and the 12T costs 21% more. On a climb the gap grows: at 8% and 8 mph the 28T costs 85 Wh a mile and the 12T 224.
The M615 drives the chainring, so the cog you ride in sets how fast the motor turns. Bafang's figures give 160 rpm with no load and 125 rpm at the rated point. With the 46T ring, the 28T turns the chainring 108 rpm at 15 mph and 144 at 20, and the model finds it the cheapest cog at every flat speed in the table.
| Speed | Cogs the motor can drive | Chainring rpm | Cheapest to costliest, throttle |
|---|---|---|---|
| 10 mph | 12T to 28T (7 of 7) | 31 to 72 | 13.8 to 16.5 Wh |
| 12 mph | 12T to 28T (7 of 7) | 37 to 86 | 15.3 to 18.2 Wh |
| 15 mph | 12T to 28T (7 of 7) | 46 to 108 | 18.1 to 21.9 Wh |
| 18 mph | 12T to 28T (7 of 7) | 55 to 129 | 21.6 to 26.6 Wh |
| 20 mph | 12T to 28T (7 of 7) | 62 to 144 | 24.4 to 30.5 Wh |
Flat pavement, a 180 lb rider, throttle only. Cogs are named by their teeth: the 28T is the largest and easiest, the 12T the smallest and hardest. A cog left out would need the chainring past the motor's no-load speed.
A climb multiplies the choice. Holding 8 mph up 8% costs 224 Wh a mile in the 12T and 85 in the 28T, so the wrong cog costs 163% more for the same hill, and pedaling easily the 28T is again the cheapest, at 57 rpm at the cranks.
| Cog (chainring rpm at 8 mph) | 6% grade, throttle | 8% grade, throttle | 8% grade, easy pedaling |
|---|---|---|---|
| 12T, hardest (25) | 145 Wh · 8 mi | 224 Wh · 5 mi | 152 Wh · 8 mi |
| 14T (29) | 118 Wh · 10 mi | 176 Wh · 7 mi | 123 Wh · 10 mi |
| 16T (33) | 100 Wh · 12 mi | 146 Wh · 8 mi | 104 Wh · 11 mi |
| 18T (37) | 88 Wh · 14 mi | 127 Wh · 9 mi | 92 Wh · 13 mi |
| 21T (43) | 77 Wh · 16 mi | 108 Wh · 11 mi | 80 Wh · 15 mi |
| 24T (49) | 70 Wh · 17 mi | 96 Wh · 13 mi | 72 Wh · 17 mi |
| 28T, easiest (57) | 63 Wh · 19 mi | 85 Wh · 14 mi | 65 Wh · 18 mi |
8 mph, a 180 lb rider; each cell is the battery cost per mile and the miles the whole pack gives at that cost.
How much does climbing cost the battery?
About 149 Wh for every 1,000 feet at 4% and 185 at 10%, on top of the same distance on the flat. Lifting 258.7 lb (a 180 lb rider on the 78.7 lb bike) through 1,000 feet takes 97 Wh at the wheel; the chain, the motor and the pack's own losses make it about 167 Wh from the battery.
Spent on nothing but lifting, the 1,200 Wh pack would climb about 7,200 feet.
| Grade | Top speed, throttle | Top speed, easy pedaling | At 8 mph, easy pedaling |
|---|---|---|---|
| 2% | 20.0 mph | 20.0 mph | 14 Wh · 85 mi |
| 4% | 20.0 mph | 20.0 mph | 29 Wh · 42 mi |
| 6% | 19.8 mph | 20.0 mph | 46 Wh · 26 mi |
| 8% | 17.2 mph | 18.2 mph | 65 Wh · 18 mi |
| 10% | 15.1 mph | 16.0 mph | 88 Wh · 14 mi |
| 12% | 13.3 mph | 14.2 mph | 112 Wh · 11 mi |
| 15% | 11.2 mph | 12.0 mph | 156 Wh · 8 mi |
| 20% | 8.9 mph | 9.5 mph | 248 Wh · 5 mi |
A 180 lb rider. The first two columns are the fastest steady speed at the M615's rated 1,000 W; on a 10% grade that is 15.1 mph on the throttle and 16.0 pedaling easily. The right-hand column spends the whole pack on that grade at 8 mph.
Price a hilly ride as its flat miles plus its climbing. Twenty miles at 15 mph on the throttle take about 361 Wh; add 2,000 feet at about 167 Wh per 1,000 and the ride needs about 695 Wh, inside the 1,020 Wh the pack gives with Eunorau's 15% kept.
Every mile is priced steady, so stops, starts and wind come on top. Eunorau's FAQ names the MAX-CARGO and the JUMBO as its only models that charge from pedaling, so on the FAT-HD a descent returns nothing to the pack.
How much does your weight cut the range?
Little on the flat, a great deal on a climb. Between 130 lb and Eunorau's 375 lb limit, the 15 mph throttle ride drops from 73 miles to 49, and the 8% climb at 8 mph with easy pedaling drops from 25 miles to 8.
| You plus your load | 15 mph flat, throttle | 20 mph flat, throttle | 8% climb at 8 mph, easy pedaling |
|---|---|---|---|
| 130 lb | 73 mi | 53 mi | 25 mi |
| 180 lb | 66 mi | 49 mi | 18 mi |
| 375 lb (the limit) | 49 mi | 39 mi | 8 mi |
Rider plus load; every row adds the bike's own 78.7 lb. The 375 lb row is the limit in Eunorau's payload guidance, which counts rider and load together.
Weight adds to what the tires and the grade cost and nothing to what the air costs, which is why the climbing column falls by more than two thirds and the flat columns by about a quarter to a third.
How much range do you lose in the cold?
At freezing, about a quarter on an easy pedaling ride. At 32 °F the 15 mph ride pedaling easily falls from 101 miles to 75, and the 20 mph throttle ride from 49 to 39.
Eunorau's listing for the 25 Ah pack names 18650 cells with no maker or model, so the central line uses McMaster University's measured LG HG2, a 3.0 Ah 18650, and the brackets come from Samsung's data sheets and Casado and colleagues' cold test.
| Air | Pack energy vs 77 °F | 15 mph, easy pedaling | 20 mph, throttle |
|---|---|---|---|
| 95 °F | 99% | 109 mi | 51 mi |
| 77 °F | 100% | 101 mi | 49 mi |
| 68 °F | 98% | 94 mi | 47 mi |
| 50 °F | 93% | 83 mi | 42 mi |
| 41 °F | 91% | 78 mi | 41 mi |
| 32 °F | 89% (80–93) | 75 mi (67–79) | 39 mi (35–41) |
| 14 °F | 82% (40–83) | 68 mi (33–68) | 35 mi (17–35) |
Usable energy against 77 °F, and the miles a full pack gives on flat pavement for a 180 lb rider: the central figure is the HG2 at a 0.5C discharge, the brackets the lowest capacity Samsung's sheets print at that temperature and the highest energy measured at a gentler rate. The cells are assumed to sit at the air's temperature.
Three losses stack at 32 °F. The pack gives about 89% of its 77 °F energy, the air is 9% denser and the tires roll 18% harder. At 95 °F the miles creep up: thinner air and softer rubber more than cover the 1% the cells lose.
How much do fat tires cost you? The Kenda Juggernaut and your riding position
Four-inch knobbed rubber is the largest single cost on a flat ride, and the model prices it at the slowest fat-bike casing on a laboratory drum. Eunorau's photographs show a Kenda Juggernaut, which Kenda sells in 26 × 4.00 as a 60 TPI Sport and in Pro and Elite casings.
The drum figure is Kenda's own 26 × 4.00 Juggernaut Pro, the slowest of the twelve fat-bike tires Bicycle Rolling Resistance lists, bracketed by the middle and the fastest of the same twelve.
| Rolling resistance | 15 mph, throttle | 15 mph, easy pedaling |
|---|---|---|
| 0.0069 · the fastest of twelve fat-bike tires on Bicycle Rolling Resistance's drum | 83 mi | 148 mi |
| 0.0105 · the middle of the same twelve | 72 mi | 114 mi |
| 0.0126 · Kenda's Juggernaut Pro 26 x 4.00 on the same drum (used) | 66 mi | 101 mi |
Pack miles on flat pavement for a 180 lb rider. Every row is one tire on Bicycle Rolling Resistance's drum, 29 km/h under 42.5 kg, converted with the site's own formula; knobs on loose ground roll harder than all of them.
The middle of the twelve gives 72 miles at 15 mph on the throttle instead of 66, so the central case leans toward fewer miles. The model also takes the drag of a rider on flat bars; sit as upright as the cruiser riders in Tengattini and Bigazzi's survey and the 20 mph throttle ride gives 46 miles instead of 49.
Is Eunorau's 60 miles real? The claim, matched to a ride
Yes, as a steady ride: 1,200 Wh over 60 miles is 20.0 Wh a mile, which the model reaches at 16.8 mph on the throttle or 19.6 mph pedaling easily, on flat pavement. Eunorau lists "Up to 60 Miles" against its one 48V 25Ah pack.
| The maker's figure | Packs | Per mile | Throttle | Easy pedaling |
|---|---|---|---|---|
| 60 mi · 25 Ah pack | 1,200 Wh | 20.0 Wh | 16.8 mph | 19.6 mph |
The steady flat speed at which 1,200 Wh spread over 60 miles matches the model's cost per mile; a 180 lb rider at 77 °F with the whole pack used.
Hold back 15%, the high end of the 10 to 15% Eunorau's FAQ says to recharge at, and the same pack gives 56 miles at 15 mph on the throttle and 86 pedaling easily.
Riding farther than the tables, or climbing more than 2,000 feet? Email us your distance, climbing, weight with gear and usual speed; we will price that ride with this model before you order. Camo $2,099, Gray $1,999; a carrier claim on transit damage reported within 48 hours is ours to file.
Buy the Camo, plan the rideHow every figure here is worked out
Holding a speed takes a steady flow of power at the rear wheel. Martin and colleagues' model, checked in 1998 against riders on a real road, gives it for still air:
Power at the wheel = v × [ m × g × (Crr × cos θ + sin θ) + ½ × ρ × CdA × v² ]
v is your speed, m the mass of rider and bike, g gravity, θ the slope, Crr the tires' rolling resistance (0.0126 means a drag of 1.26% of the weight on them), ρ the air's density and CdA your drag area, frontal size times shape. The first term is tires and hill, the second the air.
Working back from the wheel to the pack:
- The chain delivers 97.7% of the motor's work to the wheel, the drivetrain efficiency in Martin's model.
- Your legs supply their watts first and the motor the rest; a pedaling row keeps your cadence at 90 rpm or less.
- The gear fixes the motor's speed: chainring rpm = wheel rpm × cog teeth ÷ 46. Bafang's 2021 OEM workbook prints the M615 at 48 V with a 160 rpm no-load speed, rated speeds of 140 and 125 rpm for its 750 and 1,000 W ratings, and an efficiency of "≥ 80" percent; the model takes the 1,000 W rating for Eunorau's 1000 W motor and builds a motor whose losses grow with current and speed from those figures.
- The battery loses a further 3.1% inside itself at 15 mph, from the efficiency Arango, Lopez and Ceren measured on a 48 V mid-drive.
So Wh per mile = battery watts ÷ mph, and miles = 1,200 Wh × the pack's temperature share ÷ Wh per mile.
| Input | Value used | Where it comes from |
|---|---|---|
| Bike | 78.7 lb | Eunorau's specification |
| You and your load | 180 lb; the tables also run 130 and 375 | 375 lb is Eunorau's payload limit |
| Battery | 48 V × 25 Ah = 1,200 Wh | Eunorau's specification |
| Motor | 160 rpm no-load, 125 rpm at the rated 1,000 W; 160 N·m | Bafang OEM workbook 2021, M615 column; torque from Eunorau |
| Motor efficiency at rated | 75%; the surface peaks at 82% | fitted to Arango, Lopez and Ceren's measured mid-drive map |
| Gears | 46T chainring; 12, 14, 16, 18, 21, 24 and 28T cogs | Eunorau and Shimano's CS-HG200-7 exploded view |
| Wheel | 2,275 mm around | measured on Eunorau's photograph of the 26 × 4.0 tire |
| Rolling resistance | 0.0126 | Bicycle Rolling Resistance, Kenda Juggernaut Pro 26 × 4.00 |
| Drag area | 0.579 m², riders on flat bars | Tengattini and Bigazzi, 2018 |
| Pedaling cadence | 90 rpm at most | Hansen et al., 2021; Marsh and Martin, 1998 |
| Chain | 97.7% | Martin et al., 1998 |
| Battery losses | 3.1% at 15 mph, more at climbing currents | Arango, Lopez and Ceren, 2021 |
| Air | 77 °F at sea-level pressure, 1.184 kg/m³ | U.S. Standard Atmosphere, 1976 |
| Cold | the share of a cell's energy left at each temperature | McMaster University's LG HG2 cell data |
| Planning reserve | 15% kept, the top of the FAQ's 10 to 15% | Eunorau's FAQ |
A worked ride: a 180 lb rider on the throttle at 15 mph, flat pavement. The tires take 97.5 W and the air 103.3 W, so the wheel needs 200.8 W and the chainring 205.5 W.
The 28T puts the chainring at 107.6 rpm; there the motor model (back-EMF 2.865 N·m per amp, 0.378 Ω winding resistance, 1.111 A no-load current) gives 18.2 N·m at 78.3% efficiency and draws 262.5 W. Add the pack's own losses and it is 271.0 W: 18.1 Wh a mile at 15 mph, so 1,200 ÷ 18.1 comes to 66 miles.
The model was checked before a figure from it was used. Run on Martin's worked example, it matches to a tenth of a watt.
No measurement of the M615's efficiency was found, and Bafang's "≥ 80" cannot describe its rated point: at 125 of its 160 no-load rpm, the motor's back-voltage is 78% of the pack's, and no winding turns a larger share of its current's power into work than that.
So the model reads Bafang's figure as the motor's best efficiency. Its surface peaks at 82% and gives 75% at the rated point, the value that lands closest to the mid-drive map Arango, Lopez and Ceren measured: within 1.3 points across its seven readings, where the 78% ceiling misses by 12.6.
At that 78% ceiling the 15 mph throttle ride gives 78 miles instead of 66, and Bafang's other printed rating, 140 rpm at 750 W, gives 65.
What the 375 lb payload covers
Eunorau publishes a 375 lb total payload capacity, and its own definition of payload reads "Payload covers the rider and anything carried on the bike itself." So the 375 lb is you plus the rack and bag load, and the bike's own 78.7 lb is never taken out of it.
If you weigh 220 lb and carry 60 lb of gear, you are at 280 lb, with 95 lb to spare. The weight table prices the full 375 lb against the range: at 15 mph on the throttle the pack still covers about 49 miles.
The rack is part of the build. Eunorau's product record lists "REAR RACK: YES" and "FENDER: YES", and its page copy says the fenders "come with an integrated taillight".

The rack platform and the fender taillight, from Eunorau's rear three-quarter photograph.
Will the FAT-HD 1.0 Pro fit you?
The saddle reaches the fit formula's height for most riders up to about 5'11": 76 of 100 riders at that height get there, 52 of 100 at 6'0" and 14 of 100 at 6'2", because the saddle's listed top is 42.5 inches. The 30.3-inch top tube sets the lower end: 59 of 100 riders at 5'4" clear it, and 93 of 100 at 5'6".
Reaching the grips, the median rider leans 32 to 34 degrees from upright, and with the back fully relaxed the hands carry at most 21 to 23 percent of body weight.
Each figure is worked out for the 6,068 measured bodies of the US Army's anthropometric survey, with the saddle at 109% of inseam, on the frame as Eunorau photographed it.
Your fit on this bike, in three steps:
- Measure your inseam barefoot. Stand with your back to a wall, press a hardcover book up between your legs as a saddle would sit, and measure from the floor to the book's top edge.
- Find your height in the tables below and check that your inseam falls inside that row's range; a longer inseam reads like the row above.
- Check the standover table, then set the saddle when the bike arrives with the knee and heel checks near the end of this section.
Eunorau prints two rider windows and one saddle range for this frame. The product page gives 5'7" to 6'4".
Its frame-size guide sorts frames by seat tube, and this one's 480 mm (48 cm) sits on the line between its M row (43cm - 48cm, 5'6" to 5'10") and its L row (48cm - 53cm, 5'10" to 6'1"): read together, 5'6" to 6'1".
The specification lists the saddle at 33.9 to 42.5 inches from the ground, and Eunorau's own photograph shows it at 38.8 inches, inside that range. On the frame as photographed the post's collar sits 30.7 inches up and the saddle stands 3.9 inches above the post's top, so the lowest setting measures about 34.6 inches, and the tables run from 34.6 to Eunorau's listed 42.5.
Will the saddle go high enough for me?
From 5'4" to 5'9" the saddle range covers the formula height for 96 of 100 riders or more; from 6'0" up, about half or more sit above its 42.5-inch top. The formula sets the saddle at 109% of your inseam from the pedal axle (Peveler et al., 2005), and published practice goes as low as 106% (Ferrer-Roca et al., 2012).
Here that distance turns into a height off the ground through a crank axle 12.1 inches up, Eunorau's 170 mm cranks and a post leaning at 74.6 degrees.
| Your height | Typical inseam | Saddle height, median rider | At 109% | At 106% |
|---|---|---|---|---|
| 5'4" | 29.1–32.2 in | 37.8 in | 100 of 100 | 100 of 100 |
| 5'6" | 30.2–33.5 in | 39.0 in | 99 of 100 | 100 of 100 |
| 5'7" | 30.7–33.9 in | 39.5 in | 100 of 100 | 100 of 100 |
| 5'8" | 31.1–34.3 in | 40.0 in | 99 of 100 | 100 of 100 |
| 5'9" | 31.7–34.8 in | 40.6 in | 96 of 100 | 99 of 100 |
| 5'10" | 32.2–35.5 in | 41.2 in | 88 of 100 | 99 of 100 |
| 5'11" | 32.9–36.1 in | 41.8 in | 76 of 100 | 94 of 100 |
| 6'0" | 33.2–36.7 in | 42.4 in | 52 of 100 | 86 of 100 |
| 6'2" | 34.3–37.5 in | 43.6 in | 14 of 100 | 49 of 100 |
| 6'4" | 36.3–39.1 in | 45.3 in | 0 of 100 | 3 of 100 |
The ground-to-saddle height the formula gives the median rider at each height, and how many riders of 100 at that height the 34.6 to 42.5 inch range fits at 109% and at 106% of inseam. ANSUR II bodies, men and women together.
Where the post falls short, the saddle sits below the formula by a median of about 1.3 in at 6'2" and 2.8 in at 6'4". At 6'0" and taller, settle the seat post's travel before you order; a rider with a long inseam for the row reads like the row above.
Can I put a foot down at a stop?
Most riders clear the top tube from about 5'6" up: 93 of 100 at that height, and 98 of 100 at 5'7". Eunorau's geometry table gives the standover as 30.3 inches, and its diagram measures it on the top tube just ahead of the cranks.
| Your height | Typical inseam | Clear the frame, of 100 |
|---|---|---|
| 5'4" | 30.5 in | 59 |
| 5'6" | 31.7 in | 93 |
| 5'7" | 32.2 in | 98 |
| 5'8" | 32.6 in | 99 |
| 5'9" | 33.1 in | 100 |
| 5'10" | 33.8 in | 100 |
| 5'11" | 34.3 in | 100 |
| 6'0" | 34.9 in | 100 |
| 6'2" | 36.0 in | 100 |
| 6'4" | 37.6 in | 100 |
Riders of 100 at each height whose barefoot inseam clears the published 30.3-inch standover, the G line in Eunorau's geometry table. Shoes add a little; a rider who does not clear it tips the bike to put a foot down.
Eunorau prints the whole geometry as text beside its lettered diagram:
| Eunorau's geometry | FAT-HD 1.0 Pro |
|---|---|
| G · Standover | 30.3 in (770 mm) |
| A · Seat tube | 18.9 in (480 mm) |
| B · Reach | 18.3 in (466 mm) |
| C · Head tube | 5.9 in (150 mm) |
| D · Chain stay | 19.7 in (500 mm) |
| E · Bracket height | 12.6 in (320 mm) |
| H · Top tube | 23.4 in (594 mm) |
| I · Stack | 18.2 in (463 mm) |
| J · Handlebar height | 41.9 in (1,065 mm) |
| F · Wheelbase | 50.8 in (1,290 mm) |
| K · Total length | 80.3 in (2,040 mm) |
| L · Weight | 78.7 lb (35.7 kg) |

The cockpit, the headlight and the RST Guide fork, from Eunorau's front three-quarter photograph.
Will I feel cramped, or stretched?
The median rider leans 32 to 34 degrees from vertical to the grips as photographed, from 5'4" to 6'4". The grips sit 22.5 to 25.5 inches ahead of the crank axle and 28.9 to 30.1 inches above it, and the cockpit stays put while the saddle rises, which is why the lean changes so little with height.
Eunorau's geometry table gives a handlebar height of 41.9 inches where the photograph reads 42.2, and its specification lists an adjustable stem, so the lean below belongs to the photographed setting. For long, easy miles, raise it: in a study of 20 riders, "Upright trunk was found to be the most comfortable position for recreational cyclists" (Priego Quesada et al., 2017).
| Your height | Lean from upright, median rider | Across saddle and grip positions |
|---|---|---|
| 5'4" | 32° | 26–39° |
| 5'6" | 33° | 26–39° |
| 5'7" | 33° | 26–39° |
| 5'8" | 33° | 27–39° |
| 5'9" | 33° | 27–39° |
| 5'10" | 34° | 28–40° |
| 5'11" | 34° | 28–40° |
| 6'0" | 34° | 28–40° |
| 6'2" | 33° | 28–39° |
| 6'4" | 32° | 26–37° |
The median rider's lean from vertical on the photographed frame: the smallest angle at which a straight arm reaches the grips from the sit bones. The range spans the saddle's sit zone and the grip's width in the photograph.
How much weight goes through my wrists?
At most 21 to 23 percent of your weight, with the back fully relaxed. For scale, 10 road racers pedaling on the hoods put 15% of their weight on the stem (Carahalios, 2015), a lower posture than this one.
| Your height | Share of your weight, back relaxed | Median rider's weight | On each hand |
|---|---|---|---|
| 5'4" | 21% (20–23%) | 147 lb | about 16 lb |
| 5'6" | 22% (20–23%) | 166 lb | about 18 lb |
| 5'7" | 22% (20–23%) | 172 lb | about 19 lb |
| 5'8" | 22% (21–23%) | 179 lb | about 20 lb |
| 5'9" | 22% (21–24%) | 185 lb | about 21 lb |
| 5'10" | 23% (21–24%) | 192 lb | about 22 lb |
| 5'11" | 23% (22–24%) | 196 lb | about 23 lb |
| 6'0" | 23% (22–24%) | 204 lb | about 24 lb |
| 6'2" | 23% (22–24%) | 216 lb | about 25 lb |
| 6'4" | 23% (22–24%) | 220 lb | about 24 lb |
The most the hands hold with a relaxed back, from each body's segment weights (Clauser et al., 1969); the range spans the saddle and grip positions. Weights are the survey's median at each height.
On a real ride your core takes part of that load, which is why the table reads as a ceiling. For long days, padded gloves cut the pressure over the ulnar nerve by 10 to 28% in a study of 36 experienced cyclists (Slane et al., 2011).
How do I set the saddle when it arrives?
Set the saddle so your knee keeps a 25 to 35 degree bend with the pedal at the bottom (Peveler et al., 2007). The quick route is the heel check: heel on the low pedal, saddle up until that leg is just straight. It put 70% of 19 trained cyclists inside the range, more than either inseam formula (Peveler et al., 2005).
Open the seat clamp, set the height with the bike upright and your heel on the pedal, and close the clamp firmly before the first ride.
How we computed fit
The saddle sits 1.09 times your inseam above the pedal axle; the lean is the smallest trunk angle at which a straight arm reaches the grip; the hand load is the upper body's weight carried through that lean, divided by the reach to the grip.
Consider a 5'8" rider with the survey's median 32.6-inch inseam. The saddle belongs 35.6 inches from the pedal axle, 28.9 inches from the crank axle once the 170 mm crank is taken off (the LeMond route, 88.3% of inseam, gives 28.8). Along this frame's 74.6-degree post that is 40.0 inches from the ground, inside the 34.6 to 42.5 inch range.
| Input | Value | Source |
|---|---|---|
| Rider bodies | 6,068 (4,082 men, 1,986 women) | US Army ANSUR II |
| Saddle formula | 109% of inseam; range 106–110.4% | Peveler et al., 2005; Ferrer-Roca et al., 2012 |
| Saddle range | 34.6–42.5 in from the ground | lowest measured on Eunorau's photograph; highest Eunorau's listed figure |
| Crank length | 170 mm | Eunorau's specification |
| Crank axle height | 12.1 in (12.1–12.6) | measured on the photograph; Eunorau lists 320 mm, the high end |
| Seat post angle | 74.6° (74.4–74.8°) | measured on Eunorau's photograph, fitted along the post |
| Grip center | 22.5–25.5 in ahead, 28.9–30.1 in above the crank axle | measured on Eunorau's photograph |
| Standover | 30.3 in | Eunorau's geometry table |
| Segment weights | head and trunk 58.0%, each arm 4.9% of body weight | Clauser et al., 1969 |
The photograph's scale was checked against Eunorau's own table before anything was read from it.
| Dimension | Eunorau lists | Measured on its photograph | Gap |
|---|---|---|---|
| total length (the machine's extent) | 80.3 in | 81.9 in | +2.0% |
| bracket height | 12.6 in | 12.1 in | −4.0% |
| chain stay (rear axle to bottom bracket) | 19.7 in | 19.5 in | −0.8% |
| seat tube (bottom bracket to the top of the seat tube) | 18.9 in | 19.3 in | +2.1% |
| stack (bottom bracket to the top of the head tube, vertical) | 18.2 in | 25.1 in | +37.6% |
| reach (bottom bracket to the top of the head tube, horizontal) | 18.3 in | 18.9 in | +3.0% |
| head tube | 5.9 in | 5.4 in | −8.4% |
| handlebar height (ground to the top of the bar) | 41.9 in | 42.2 in | +0.7% |
| standover (the frame's top edge where a rider straddles it) | 30.3 in | 30.8 in | +1.5% |
Scale from the published 50.8-inch wheelbase, axle center to axle center, the axles fitted to each tire's outer edge on Eunorau's drive-side photograph. Six figures land within 3.5% of Eunorau's and set the scale; the bracket height is carried as a bracket, and the stack and head tube are shown and not used.
The formula holds on the survey itself: across its bodies, the LeMond route plus a 170 mm crank lands at 109.0% of inseam from the pedal, against 109.2 ± 0.9% measured in trained cyclists (Peveler et al., 2005). The hand figure is a ceiling, and its only measured anchor is the road racers above.
6'0" or taller, under 5'6", or between two rows? Email your height and inseam to support@redtailebikes.com and we will put them through this model and ask Eunorau for the seat post's travel in writing before you order. Prefer the camouflage finish? That build costs $2,099.
Buy the FAT-HD in GrayThe Mercer fit test
The Mercers are the fixed cast of American riders every machine on this site is held against, each verdict read from a published number and the fit model's row at that rider's height.
The numbers in play: Eunorau's 5'7"–6'4" window and its size guide's 5'6"–6'1" rows for a 48 cm seat tube, the 30.3-inch standover, the saddle's 34.6 to 42.5 inches on this frame, 375 lb of payload, 78.7 lb, and the class question in the section below.
| Member | Verdict | The number behind it |
|---|---|---|
| Dana Mercer, 45, 5'7" | Yes. | At the floor of Eunorau's window and inside the size guide's 5'6"–5'10" row. 98 of 100 riders her height clear the top tube, and her formula height, 39.5 in, sits mid-range on the saddle. |
| Frank Kowalski, 63, 5'10" | Yes. | Inside both of Eunorau's windows. Every rider his height clears the top tube, and 88 of 100 reach the formula saddle height; his median figure, 41.2 in, sits under the 42.5 in top. |
| Jack Mercer, 48, 6'1" | The frame yes; confirm the seat post. | Inside the window and the size guide's 5'10"–6'1" row. His formula height, 43.2 in, sits above the saddle's listed 42.5 in top: 29 of 100 riders his height reach it, and the rest sit a median of 1.0 in short, so the post's travel is the number to settle before ordering. |
| Maya Torres, 32, 5'6" | Her body fits; her commute is the question. | An inch under the product page's floor and inside the size guide's 5'6"–5'10" row; 93 of 100 riders her height clear the top tube. Her ride is a city commute, and a 1000 W machine sits outside the e-bike definition in the 44 states that draw a 750 W line, so the Defender and its 500 W motor are the better match. |
| Ruth Kowalski, 61, 5'5" | Below Eunorau's window. | Two inches under the 5'7" floor. The model's 5'5" row has 80 of 100 riders clearing the top tube, printed for reference beside Eunorau's window; the SPECTER-ST 2.0, a step-through whose window starts at 5'3", is the bike in our Eunorau range that includes her height. |
| Cole Mercer, 16, 5'11" | Not on public roads. | His height clears the window and the top tube, and 76 of 100 riders at 5'11" reach the formula saddle height. The published 1000 W sits above the 750 W line in 44 states' e-bike definitions, so the rules for whatever class his state puts it in apply; the state guide carries each one. On private land, with a helmet, it is his parents' call. |
| Ivy Mercer, 12 | No. | Eunorau publishes a 5'7" rider floor for a 78.7 lb machine with a thumb throttle and 160 N·m at the cranks. |
Dana and Frank sit in the middle of what this frame serves; Jack fits it with one number to confirm, and Ruth's height points to a bike with a lower floor.
Between 5'7" and 6'0"? The tables put you inside this frame. Choose Gray here or the $2,099 Camo; neither color adds a shipping charge anywhere in the contiguous US.
Buy it in Gray for $1,9991000 watts, 20 mph, and all 51 jurisdictions
This section decides where the bike counts as a bicycle, so every line in it is built from a statute, and each statute is linked.
Eunorau publishes 1000 W, 20 mph and a thumb throttle. On September 26, 2026 those three facts were screened against the electric-bicycle definition in all 50 states and the District of Columbia, from our rule table, in which every row carries its own statutory citation.
The federal reference point is 15 U.S.C. § 2085(b), which defines a low-speed electric bicycle by a motor of less than 750 watts and a motor-only top speed of less than 20 mph with a 170-pound rider. That definition governs how the Consumer Product Safety Commission treats the product; where you may ride it is set by your state, and states write their own definitions.
The result: 4 QUALIFY · 45 OUTSIDE THE DEFINITION · 2 PUBLISH NO DEFINITION.
In 44 of the 45 the reason is the wattage: the state writes a 750 W line into its definition and 1000 W is above it. The 45th is New Jersey, whose definition, as amended by P.L.2025, c.285, sets no motor-power figure and assists "only when the rider is pedaling", so any throttle-equipped bike sits outside it.
Alaska (AS 28.90.990) and Kentucky (KRS 189.010) publish no e-bike definition for the figures to sit inside or outside.
The four where the published figures qualify
Three of the four write no wattage into the definition at all, and the fourth writes a ceiling above 1000 W. All four take the bike at its 20 mph setting.
| Jurisdiction | Its own words, read September 26, 2026 |
|---|---|
| District of Columbia | a "motorized bicycle" has "A motor incapable of propelling the device at a speed of more than 20 miles per hour on level ground", and no wattage limb |
| Montana | a motor that carries "a rider who weighs 170 pounds no faster than 20 miles an hour on a paved, level surface", and no wattage limb |
| Oregon | Class 2 "[c]eases to provide assistance" at 20 miles per hour; no wattage limb |
| Rhode Island | a motor "rated not more than two (2) (S.A.E.) horsepower"; Class 2 is "throttle-actuated" and "ceases to provide assistance" at 20 mph (§ 31-19.7-1) |
Two horsepower is about 1,491 W, so Rhode Island's ceiling sits above the FAT-HD's 1000 W. The District calls the machine a "motorized bicycle" rather than an electric bicycle, and the screen reads the definition the District writes.
Outside a definition, a different set of rules applies. Three states name the class a 1000 W two-wheeler lands in, in their own text. South Carolina's moped is "designed to have an input exceeding 750 watts and no more than 1500 watts" (§ 56-1-10(26)); Virginia's moped "has an input of 1500 watts or less"; and Maine's has "an electric motor with a capacity under 1,500 watts" (§ 101(36)).
There the questions become registration, licensing and where a moped may go, and our state-by-state guide carries each state's page.
Takeaway
- 4 of 51 at the 20 mph setting. The District of Columbia, Montana, Oregon and Rhode Island take the published 1000 W and 20 mph as a bicycle.
- 44 states draw a 750 W line, and 1000 W is above it.
- New Jersey's test is the throttle: its definition takes any throttle-equipped bike outside it.
- Outside means another class. South Carolina, Virginia and Maine name the moped class in their own words.
- Raise the speed limit and the four become none. Each of the four stops the motor, or the throttle class, at 20 mph (the next section).
What the AI engines tell buyers, and what the statutes say
Asked "are 1000w ebikes legal" on September 26, 2026, the engine answered from retailer and brand blogs, with no statute cited: "Six states specifically allow eBikes to have a max power of 1000W; these are Georgia, Kansas, Minnesota, Oklahoma, Oregon, and Virginia." It gave the same sentence on September 6. Each of the six, read at its publisher the same day:
| State | The statute's own words, September 26, 2026 |
|---|---|
| Georgia | "not more than 750 watts", in HB 454 (2019) as signed |
| Kansas | "less than 750 watts" |
| Minnesota | "not more than 750 watts" |
| Oklahoma | "not more than seven hundred fifty (750) watts" |
| Virginia | "no more than 750 watts" |
| Oregon | no wattage figure in the definition |
Five of the six write a 750 W ceiling. The sixth is the one the answer gets right, and it is among the four that take the FAT-HD at 20 mph.
California, and one word on the spec sheet
California turns on wording as well as arithmetic. Cal. Veh. Code § 312.5(a) takes a motor that "does not exceed 750 watts of power", and subsection (d)(1) removes from the definition a vehicle "intended by the manufacturer to be modifiable to attain a speed greater than 20 miles per hour on motor power alone or to attain more than 750 watts of power".
Eunorau's highlights label the FAT-HD "Class 2 Speed limited Unlockable". Whether that label is what (d)(1) means is California's question to answer; at 1000 W the bike sits above the 750 W line of subsection (a) either way.
Riding in one of the four, or on your own land? The Gray is $1,999 and the Camo $2,099, with no delivery charge to the 48 contiguous states.
Buy the Gray one — $1,999What "Class 2, unlockable" asks of you
Eunorau publishes the limit as 20 mph and the word "Unlockable" beside it. Unlocking guides online treat a raised limit as a setting, a menu entry or an app toggle; at the statute line it can change the bike's class.
At 20 mph, four jurisdictions take this bike as a bicycle. Above 20 mph, none of them do. The District of Columbia's motor must be "incapable" of more than 20 mph, Montana's no faster than 20, and Oregon's and Rhode Island's Class 2 throttles "cease" at 20. Everywhere else with a definition, the 1000 W rating or the throttle already sits outside it before the speed setting is touched.
Leave it at 20 mph anywhere public. A raised limit is for land where you set the rules, and it is a choice you make; we publish no unlocking procedure and quote Eunorau's word only.
Cadence sensing, and what it feels like
Eunorau describes "160Nm of cadence-sensing assist" and lists a "Bafang BBSHD Gear Sensor". Bafang's own table for the M615 gives its pedal sensor as "Speed", where the torque-sensing M445 beside it reads "Speed & Torque Integrated", and the 2019 review's drive-mode field says "Cadence Sensing Pedal Assist".

The Camo from the non-drive side: the motor housing at the cranks, the rear rotor and the kickstand, in Eunorau's photograph.
A speed sensor reads that the cranks are turning; a torque sensor reads how hard they are pushed. On this bike the assist level, 0 to 5, is the setting you ride with, and the sensor's job is to know you are pedaling.
On a loaded climb in a low gear that makes your effort simple to plan: you choose the level and the cog, and keep the cranks turning. If you want assist that rises and falls with your own push, the SPECTER-ST 2.0's M620 senses torque, and our e-bike motor guide sets the two systems side by side.
Charging, against the charger in the box
Eunorau prints a charging time of "4 - 6 hours" in its product record and a "US standard 2.0 A smart charger" in its specification. Its own charger listing supplies the constant that links them: a 54.6 V output. At 2.0 amps that is 109.2 watts.
At 109.2 watts, 1,200 watt-hours take 11.0 hours, before any loss or the slow finish every lithium charge has. A four-hour refill would need 5.5 amps and a six-hour refill 3.7.
The printed window fits the smaller pack this one replaced. Eunorau's 48V 16.5 Ah battery held 792 Wh, and on the $69 3 A charger Eunorau sells, at the same 54.6 V, that pack refills in about 4.8 hours; the 25 Ah pack on the same charger takes about 7.3.
So charge yours overnight on the unit in the box. Plug it in when you get home and it is full by morning. The pack's listing gives its charging range as 0 to 45 °C, so charge it where the air is above 32 °F.
Which of Eunorau's figures this review uses
Eunorau prints the FAT-HD's specification three times: a table in its product record, a rendered block on its product page, and the page's feature copy. A few figures differ between them; the last column names the one this review uses.
| Specification | What Eunorau prints, and where | This review uses |
|---|---|---|
| Rear cogs | "Shimano 12-28T" in the specification; "Shimano Derailleur 7-Speed Freewheel" in the record; "7 speed freewheel" in the copy | 12–28T, the only toothed figure printed |
| Pedals | "Aluminum Alloy pedal with reflectors" in the specification; "High Quality Nylon Pedals" in the record | alloy |
| Box | 156 × 34.5 × 85 cm in the specification; 156 × 32.5 × 88 cm in the record | not used |
| Range | "Up to 60 Miles" in the specification; "60 Miles" in the record | up to 60 miles |
| Tires | "Kenda Tires 26" x 4.0"" in the specification; its photographs show a Kenda Juggernaut casing marked "30 TPI CASING WIRE BEAD" | Kenda Juggernaut, 26 × 4.0 |
| Spare 25 Ah pack | "Capacity 25AH" beside "Rate 672WH" and "Configuration 13S4P" on its listing | 48 V × 25 Ah = 1,200 Wh |
Read from Eunorau's product page, product record and battery listing on September 26, 2026.

The sidewall in Eunorau's photograph reads JUGGERNAUT and 30 TPI CASING WIRE BEAD, which is why the tire row names the casing.
The tooth counts set the gearing, so the model takes them from Shimano. Shimano's seven-speed 12–28T, the CS-HG200-7, carries 12, 14, 16, 18, 21, 24 and 28 teeth, and the range tables use those seven cogs.
On September 26, 2026 an AI engine repeated a retailer's "Kenda Krusade Sport" for this bike's tires; Eunorau's own photographs show the Juggernaut, and so did the 2019 review's tire field.
Has it been recalled?
No CPSC recall names Eunorau or the FAT-HD, checked on September 26, 2026 across the recall database's title, description and product-name fields; each field returned records for a control query the same minute, so the empty answer for Eunorau is a finding, not a failed search.
The CPSC's product safety warning listing, read in full the same day, holds 373 warnings: 2 name the control brand, and none names Eunorau, the FAT-HD or the Hunter X7.
Is it UL certified?
Eunorau marks this model "UL CERTIFIED: Yes" in its product page's highlights. UL 2849 is the standard for an e-bike's electrical system and UL 2271 the one for its battery pack.
A building, campus or insurer that wants the certificate itself can have it: tell us before you order and we will get it from Eunorau and send it to you.
The warranty, and who files the claim
The terms below are Eunorau's published warranty policy, read on September 26, 2026:
| Component | Coverage |
|---|---|
| Frame | 10 years |
| Battery | 24 months |
| Motor | 24 months |
| Electrical components | 24 months |
The policy is issued by "Eunorau Bikes, a Nevada corporation", for bikes bought in the United States on or after August 1, 2023, and covers manufacturing defects in Eunorau's original parts.
It stays with "the original purchaser", asks for "Product Registration right after the purchase" and an "E-bike check-up by a Eunorau specialist or dealer after the first year of use", and excludes ordinary wear and labor. The Eunorau brand profile sets these terms beside the rest of the range.
When something fails, the claim is ours to run. Buy the FAT-HD from Redtail, tell us what broke, and we file it with Eunorau and track it to the part in your hands.
Buying it from us

The Camo build from the front three-quarter, in Eunorau's photograph: the headlight, the RST Guide fork and the fenders.
| What we say | The document behind it |
|---|---|
| Gray $1,999, Camo $2,099 | Our listing, September 26, 2026 |
| Both colors orderable | Our listing, September 26, 2026 |
| Shop Pay: 3 or 12 monthly payments at 15% APR | Our listing's plan table, September 26, 2026 |
| Eunorau's own prices, $1,999 and $2,099, against its listed $2,399 and $2,499 | Eunorau's page, September 26, 2026 |
| We file the warranty claim | Eunorau's warranty terms, plus our own handling |
| Free shipping in the contiguous US | Our shipping policy |
The value case in numbers. With Shop Pay, the $1,999 Gray could be split into 12 monthly payments of $180.43 at 15% APR, or 3 of $683.06, on the plans our listing offered on September 26, 2026.*
*Rates from 0-36% APR. Payment options through Shop Pay Installments are subject to an eligibility check and are provided by these lending partners: affirm.com/lenders. Options depend on your purchase amount, and a down payment may be required. State notices to consumers: affirm.com/licenses.
Why buy it here. The price Eunorau charges, delivery to the lower 48 at no cost, US support by email, and every warranty claim run by us with Eunorau.
Write to us with your height, inseam, state and the load you carry, and we will tell you plainly whether this is the bike, the FAT-HS or the Defender, including when it is none of them.
The honest ledger
Green flags
- 1,200 Wh on one pack from $1,999: about 66 miles at 15 mph on the throttle for a 180 lb rider on flat pavement (the range tables).
- 375 lb of payload for you and your gear, with the bike's 78.7 lb outside it.
- A mid-drive that uses the gears: an 8% climb at 8 mph costs 85 Wh a mile in the 28T against 224 in the 12T (the gear tables).
- Hydraulic discs, 180 mm and 160 mm, with motor cutoff in both levers.
- Rack, fenders, lights and kickstand on the bike, with none of it sold back as an accessory.
- Catalog parts: Bafang, Shimano, Kenda, RST and PROMAX, so a replacement is a part number.
- Fit data, published: a rider window, a saddle range and a full geometry table, which is what the fit tables are built from.
Red flags: where it is the wrong bike, and what to do
- 1000 W is above the 750 W line 44 states draw into the e-bike definition: for a daily commute on public paths, take the Defender (500 W) and read our Defender review.
- 100 mm of fork travel and no rear suspension: for rough trail, take the SPECTER-ST 2.0 or the full-suspension FAT-HS, and our FAT-HS review sets out what its rear shock buys.
- The 30.3-inch top tube: at 5'4", 59 of 100 riders clear it; under about 5'6", read the standover table, and look at the SPECTER-ST 2.0, a step-through with a 19.3-inch standover.
- The saddle's listed top is 42.5 inches: from 6'0" up about half of riders or more need it higher, so ask us for the seat post's travel before you order (the saddle table).
- Cadence sensing: assist follows pedal rotation; for assist that follows your effort, the SPECTER-ST 2.0's M620 senses torque.
- About 11 hours on the 2.0 A charger: charge overnight, or add Eunorau's $69 3 A charger for about 7.3 hours (the charging section).
- 78.7 lb: the motor carries it on the ride; onto a car it is a hitch rack's job or a two-person lift, so plan transport first (the checklist).
Who should buy it
The range and the fit in one line each. About 66 miles at 15 mph on the throttle from the 1,200 Wh pack, for a 180 lb rider on flat pavement; 98 of 100 riders at 5'7" clear the top tube, and 52 of 100 at 6'0" reach the formula saddle height.
Buy the FAT-HD 1.0 Pro if you want 1,200 Wh in one pack for $1,999, carry gear down fire roads, farm tracks and private land, and the fit tables put you between about 5'6" and 6'0". Take the Camo if the bike goes to the woods, and the Gray if it does not.
Take the FAT-HS instead if the ground is rough enough to want a rear shock: $3,449, suspension at both ends, two frame sizes, and a second pack on the 19-inch frame. Take the FAT-HD 2.0 ($2,039) if you want a smaller main pack with room for a second; our FAT-HD 2.0 review covers it.
Do not buy it for a commute on public paths: the 1000 W rating is above the 750 W line in 44 states' e-bike definitions, and our reviews index lists commuters that sit inside it.
The Camo, for the woods, at $2,099. Prefer it in Gray? That one is $1,999. Shop Pay at checkout, free freight to your door in the lower 48, and warranty claims filed by us.
Buy the Camo build — $2,099Before you buy: the checklist
Nine things to settle before the FAT-HD ships. The first three decide whether it is your bike; the rest take a few minutes each and protect your return window.
- ☐ Read your own state's definition for a 1000 W, 20 mph machine; start with our state guide.
- ☐ Measure your inseam barefoot and read the standover table against the 30.3 in top tube.
- ☐ If you are 6'0" or taller, ask us for the seat post's travel before you order.
- ☐ Add up you and your load against the 375 lb payload; the bike's 78.7 lb is separate.
- ☐ Plan an overnight charge on the 2.0 A unit, or budget $69 for Eunorau's 3 A charger.
- ☐ Charge above 32 °F: the pack's listing gives 0 to 45 °C.
- ☐ If a UL certificate is required where the bike lives, ask us for it before ordering.
- ☐ Line up a hitch rack or a second person for a 78.7 lb bike.
- ☐ Photograph the crate before you open it: transit damage has to reach us within 48 hours.
Limitations of this review
Twenty limits on what this review can tell you, numbered so each can be checked against the section it qualifies.
- Every bike specification on this page is Eunorau's own, verified at its page and recomputed. The range and fit models, the 2019 review's figures, the jurisdiction screen and our store terms are the exceptions, each named below.
- Every range figure is a steady ride: one speed on one grade, no wind, no stops. Starts, stops and headwinds cost more; a tailwind costs less.
- The 2019 figures are Electric Bike Review's labeled fields, read on September 26, 2026; they describe the build it rode, and the page never mixes them with today's.
- Eunorau prints the rear cogs, pedals, box and range two ways (the conflicts table); the review uses the figure named there.
- The jurisdiction screen reads the published 1000 W, 20 mph and throttle against each definition as our rule table records it on September 26, 2026, each row with its citation. It is a reading of statutes, not legal advice. Georgia's 750 W language is read in HB 454 (2019) as signed; Georgia's official compilation, published through LexisNexis, was not read.
- Recalls were screened on September 26, 2026 on three fields of the CPSC's recall database, each returning records for a control the same minute, and the CPSC's full warning listing was read the same day; none names Eunorau or the FAT-HD.
- Our price, orderability and Shop Pay terms are read from our own listing on September 26, 2026; the payment figures are its plan table for the $1,999 Gray at 15% APR.
- The motor's efficiency is fitted, not measured. Bafang prints the M615 at "≥ 80" percent, which cannot hold at its 125 rpm rated point on a 160 rpm no-load speed; the model reads it as the peak and fits the rated point at 75%, closest to the measured map of another 48 V mid-drive. At the 78% ceiling the 15 mph throttle ride gives 78 miles instead of 66.
- No drum measurement of the Juggernaut Sport was found. The tables price Kenda's Juggernaut Pro 26 × 4.00, the slowest of Bicycle Rolling Resistance's twelve fat-bike casings; the middle of the twelve gives 72 miles instead of 66 at 15 mph on the throttle.
- Eunorau names 18650 cells for the pack without a maker or model, so the cold rows use McMaster's measured LG HG2, a 3.0 Ah 18650, bracketed by Samsung's data sheets.
- Eunorau's pack listing prints "Rate 672WH" beside "Capacity 25AH". The model uses 48 V × 25 Ah = 1,200 Wh; at 672 Wh the 15 mph throttle ride would cover about 37 miles instead of 66.
- The fit figures describe Army bodies, not the public. The 6,068 people in the ANSUR II survey are US Army personnel aged 17 to 58, measured in 2010 to 2012; how inseam and reach vary at one height carries over to civilians, the exact spread may not.
- The fit model is the frame as Eunorau photographed it, scaled by the published wheelbase and checked on six published dimensions.
- The photograph's bracket height reads 12.1 in against Eunorau's 12.6. The saddle table runs at the photograph's figure; at the listed one each rider's formula height sits about 0.5 in higher.
- The saddle range runs from a measured 34.6 in to Eunorau's listed 42.5 in. Eunorau lists 33.9 in as the lowest; on this frame the collar and the saddle's own height put the lowest setting at 34.6, so the model uses that, and the post's travel is the number to confirm with us.
- The cockpit is the one Eunorau photographed. The stem is adjustable, and where the sit bones rest on this saddle is not published, so the lean and hand tables span its range.
- The hand figure is a ceiling. It assumes a fully relaxed back, so the hands hold everything the trunk does not; any core effort lowers it.
- The wheel's size is measured on the photograph, 28.5 in across the front tire; at the 26 × 4.00 size's nominal 30.0 in, the 15 mph and 20 mph throttle rides move by less than a tenth of a mile.
- The formula is a starting point. In 19 trained cyclists the inseam formulas put 55 to 65% inside the 25 to 35 degree knee range and the heel check 70% (Peveler et al., 2005), so set the final height on the bike.
- Expiry: re-verify if Eunorau changes the payload, rider window, speed setting, range, saddle range or pack, publishes the seat post's travel or a UL certificate, if our price moves, or if any state's definition changes.
The source register
Every source this review cites, by tier: Eunorau's own pages and records, the statutes, the federal recall and warning lists, the measurements behind the range and fit models, and our own datasets, each beside what it was used for.
| Source | Tier | Used for |
|---|---|---|
| Eunorau FAT-HD product page and product record, read September 26, 2026 | T2 — manufacturer primary | Every specification, the geometry, the range claim, the 16.5 Ah note, the motor's description |
| Eunorau battery listing · charger listing | T2 — manufacturer primary | The pack's cells, charge range and printed rate; the charger's 54.6 V and $69 |
| Eunorau warranty · FAQ · frame-size guide · payload guide | T2 — manufacturer primary | Warranty terms; the advice to recharge with 10-15% left and where the bikes are made; the size chart; Eunorau's definition of payload |
| 15 U.S.C. § 2085 · the District of Columbia, Montana, Oregon, Rhode Island, New Jersey, South Carolina, Virginia, Maine, California, Georgia, Kansas, Minnesota, Oklahoma, Alaska and Kentucky texts, linked above | T1 — statute | The federal definition, the four that qualify, the three moped classes, and the six the AI answer names |
| Our 51-jurisdiction rule table, each row with its statutory citation | First-party dataset, disclosed | The screen of September 26, 2026 |
| CPSC recall database · CPSC warning listing | T1 — federal agency | The recall and warning screens of September 26, 2026 |
| Electric Bike Review, EUNORAU FAT-HD Review, March 19, 2019 | T4 — independent review | The 2019 build's figures, labeled as such |
| Bafang, OEM workbook 2021, M615 column · Shimano CS-HG200-7 | T2 — component maker primary | The motor's speeds, ratings and sensor; the seven cog sizes |
| Martin et al., 1998 · Tengattini and Bigazzi, 2018 · Arango, Lopez and Ceren, 2021 | T2 — peer-reviewed measurement | The power model and chain efficiency; riders' drag area; battery losses and the measured mid-drive map |
| McMaster HG2 data; Samsung's 35E sheet; Casado et al., 2025 · U.S. Standard Atmosphere, 1976 · Rothhämel, 2023 | T1 / T2 | Cell energy by temperature; air density; rolling resistance by temperature |
| Bicycle Rolling Resistance, Kenda Juggernaut Pro · Kenda, Juggernaut Sport · Hansen et al., 2021 | T2 — independent lab; maker primary; peer-reviewed | Fat-bike drum figures; the Juggernaut's sizes; the 90 rpm pedaling limit |
| US Army ANSUR II · Peveler et al., 2005 and 2007 · Ferrer-Roca et al., 2012 · Priego Quesada et al., 2017 · Slane et al., 2011 · Carahalios, 2015 · Clauser et al., 1969 | T1 / T2 — federal survey, peer-reviewed or institutional | The 6,068 bodies; the saddle formula, knee target and heel check; the comfort finding; glove padding; the hand-load anchor; segment weights |
| Our listing, refund policy and shipping policy · Affirm, lending partners | T2 — first party; lender primary | Price, colors, Shop Pay plans, our return and shipping terms; who provides the installment plans |
| Our own computations, each worked from the sources in this register | First-party datasets, disclosed | The range and fit models, the pack energy, the charging hours and the payments |
Frequently asked questions
How fast does the Eunorau FAT-HD 1.0 Pro go?
20 mph, per Eunorau's specification, and the limit is labeled "Unlockable". At 20 mph the published figures sit inside the e-bike definition in four jurisdictions; above it they sit inside none, so leave the limit where it ships on any public road, path or trail.
How far will the FAT-HD 1.0 Pro actually go on one charge?
On flat pavement a 180 lb rider gets about 66 miles at 15 mph on the throttle and 49 at 20 mph, and past 100 at 15 mph pedaling easily. Each 1,000 feet of climbing takes about 149 to 185 Wh on top, and a 375 lb rider-and-load gets about 49 miles at 15 mph; the range tables cover hills, weight and cold.
How big is the battery on the FAT-HD 1.0 Pro?
48V 25 Ah, which is 1,200 Wh, in one downtube pack. Eunorau's page says it replaced a 16.5 Ah battery at no extra cost, and it sells the 25 Ah pack as a spare for $699.
Is a 1,000 W electric bike street legal?
Not as an electric bicycle in most of the country. Screened on September 26, 2026, the FAT-HD's 1000 W, 20 mph and throttle sit inside the definition in the District of Columbia, Montana, Oregon and Rhode Island, and outside it in the 44 states that draw a 750 W line and in New Jersey; Alaska and Kentucky publish none. Outside the definition, a state's other vehicle rules apply.
Which states allow 1,000 W e-bikes?
Four jurisdictions take this bike's published figures as a bicycle at 20 mph: the District of Columbia, Montana and Oregon, which write no wattage into their definitions, and Rhode Island, whose ceiling is two horsepower. The six states an AI answer names were read at their publishers, and five of them write 750 watts. The one that holds is Oregon.
How long does the FAT-HD 1.0 Pro take to charge?
About 11 hours from empty on the 2.0 A charger in the box, since 1,200 Wh at 109.2 W takes 11.0 hours before losses. Eunorau's printed "4 - 6 hours" fits the smaller 16.5 Ah pack on its $69 3 A charger; the 25 Ah pack on that charger takes about 7.3.
Does the FAT-HD 1.0 Pro have a torque sensor?
No: Eunorau describes "cadence-sensing assist", and Bafang's own table gives the M615's pedal sensor as "Speed". The assist follows the cranks turning at the level you choose, and a torque sensor would follow how hard you push.
How much weight can the FAT-HD 1.0 Pro carry?
375 lb of rider and cargo. Eunorau defines payload as the rider and anything carried on the bike, so the bike's own 78.7 lb sits outside the 375; a 220 lb rider carrying 60 lb of gear has 95 lb in hand.
How tall do you need to be to ride the FAT-HD 1.0 Pro?
Eunorau publishes 5'7" to 6'4". In the fit model, 98 of 100 riders at 5'7" clear the 30.3-inch top tube, and the saddle reaches the formula height for most riders up to about 5'11"; at 6'2", 14 of 100 reach it, so tall riders confirm the seat post's travel first.
A 5'8" rider with the survey's median 32.6-inch inseam sets the saddle about 40.0 inches from the ground.
Will I be too stretched out on the FAT-HD 1.0 Pro?
The median rider leans about 32 to 34 degrees from upright to the grips as Eunorau photographed the cockpit, from 5'4" to 6'4". The stem is adjustable; raising it sits you taller, and an upright trunk was the most comfortable position in a study of recreational cyclists.
What is the Hunter X7?
The same bike. Eunorau titles the model "FAT-HD 1.0 Pro / Hunter X7" on its product page, and our listing sells it as the FAT-HD 1.0 Pro.
Is the Eunorau FAT-HD 1.0 Pro UL certified?
Eunorau marks it "UL CERTIFIED: Yes" on its product page. UL 2849 covers an e-bike's electrical system and UL 2271 its pack; if your building or insurer needs the certificate itself, tell us before you order and we will get it from Eunorau.
Has the Eunorau FAT-HD 1.0 Pro been recalled?
No CPSC recall names Eunorau or the FAT-HD, checked on September 26, 2026 on three fields of the recall database, each of which returned records for a control query. The CPSC's warning listing, read the same day, names neither.
What is the difference between the FAT-HD 1.0 Pro and the FAT-HD 2.0?
The pack and the price. Eunorau lists the 1.0 Pro with one 48V 25 Ah battery, 1,200 Wh, and the 2.0 with a 48V 15 Ah battery plus an optional second 15 Ah pack; both carry a 1000 W mid-drive. The 1.0 Pro is $1,999 here and the 2.0 $2,399, and our FAT-HD 2.0 review covers the 2.0.
Does it come with a rack and fenders?
Yes. Eunorau's product record lists "REAR RACK: YES" and "FENDER: YES", with a headlight and a taillight, and its copy says the fenders carry an integrated taillight.
Can I ride it on public trails and bike paths?
Only where your state's definition takes it as a bicycle and the trail allows e-bikes. At its 20 mph setting that is four jurisdictions; in every other state with a definition, the bike falls into another class. Read your state's page in our state guide and the trail's own rules.
The bottom line
The FAT-HD 1.0 Pro is the fat bike for carrying you and a load a long way on one pack: 1,200 Wh, 375 lb of payload for rider and gear, and a 160 N·m mid-drive working through seven cogs.
The pack is the decision. From $1,999 it gives a 180 lb rider about 66 miles at 15 mph on the throttle on flat pavement, and the 28T cog keeps an 8% climb at 85 Wh a mile.
One thing to settle before you pay: at 1000 W the bike is above the 750 W line in 44 states' e-bike definitions, and inside the definition at 20 mph in the District of Columbia, Montana, Oregon and Rhode Island; the class section shows why.
Buy it if the job is gear down a fire road and the fit tables put you on this frame.
$1,999 in Gray, with freight included to any address in the 48 contiguous states. The camouflage build is $2,099. Not sure it fits? Ask us with your height and inseam.
Buy the Gray build — $1,999References
- Eunorau. FAT-HD 1.0 Pro / Hunter X7 — product page and product record: highlights, specification block, description table, geometry and page copy. eunorau-ebike.com/products/fat-hd; product record fat-hd.json, created September 24, 2017. Retrieved September 6 and September 26, 2026; deposit copies and the maker's gallery archived.
- Eunorau. 48V25AH Reention Dorado ID-MAX Case Battery: the models it fits, its cells, printed rate, charging range and price. eunorau-ebike.com. Retrieved September 26, 2026; deposit copy archived.
- Eunorau. 48V3A 1.0 US/CA Ebike Fast Charger: output voltage 54.6 V, 3 A, $69. eunorau-ebike.com. Retrieved September 26, 2026; deposit copy archived.
- Eunorau Bikes. 24-Month+ Limited Warranty: coverage periods, requirements, exclusions and the issuing entity. eunorau-ebike.com/pages/warranty. Retrieved September 26, 2026; deposit copy archived.
- Eunorau. Hunting Ebike Trailer Guide: How Much Gear Can You Tow. eunorau-ebike.com. May 31, 2026; retrieved September 24, 2026. Eunorau's own definition of payload.
- Eunorau. EUNORAU EBIKES FAQ: the advice to recharge with 10-15% left, and the models that charge from pedaling. eunorau-ebike.com/pages/faqs. Retrieved September 26, 2026.
- Eunorau. Frame Size Suggestion (rider height against frame size, in inches and centimeters). eunorau-ebike.com/pages/frame-size-suggestion. Retrieved September 26, 2026.
- Redtail eBikes. FAT-HD 1.0 Pro store record (redtailebikes.com/products/eunorau-fat-hd-1-pro): both colors, prices and the Shop Pay plan table, and our refund and shipping policies. Retrieved September 26, 2026. First party.
- Affirm. Lending partners. affirm.com/lenders. The lenders behind Shop Pay's installment plans, named in Shopify's installment terms.
- United States. 15 U.S.C. § 2085 — Low-speed electric bicycles. Pinpoint § 2085(b). law.cornell.edu. Retrieved September 26, 2026.
- Council of the District of Columbia. D.C. Code § 50-2201.02(11A), "Motorized bicycle." code.dccouncil.gov. Retrieved September 26, 2026. "A motor incapable of propelling the device at a speed of more than 20 miles per hour on level ground".
- Montana Legislature. MCA § 61-8-102(7), "Electrically assisted bicycle." archive.legmt.gov. Retrieved September 26, 2026. "a rider who weighs 170 pounds no faster than 20 miles an hour on a paved, level surface".
- Oregon Legislature. ORS 801.258, "Electric assisted bicycle." As amended by 2024 c.12 § 1. oregonlegislature.gov. Retrieved September 26, 2026. The Class 2 definition and the absence of any wattage limit.
- Rhode Island General Assembly. R.I. Gen. Laws § 31-1-3(g), "Electric motorized bicycle", webserver.rilegislature.gov, and § 31-19.7-1, "Classes" (P.L. 2024, ch. 172 and ch. 173), webserver.rilegislature.gov. Retrieved September 26, 2026. "rated not more than two (2) (S.A.E.) horsepower"; Class 2 "throttle-actuated".
- South Carolina Legislature. S.C. Code § 56-1-10(26), "Moped." Title 56, Chapter 1. scstatehouse.gov. Retrieved September 26, 2026. "designed to have an input exceeding 750 watts and no more than 1500 watts".
- Virginia General Assembly. Va. Code § 46.2-100, "Electric power-assisted bicycle" and "Moped." law.lis.virginia.gov. Retrieved September 26, 2026. "no more than 750 watts"; the moped "has an input of 1500 watts or less".
- Maine Legislature. 29-A M.R.S. § 101(36), "Moped." legislature.maine.gov. Retrieved September 26, 2026. "an electric motor with a capacity under 1,500 watts".
- California Legislative Information. Cal. Veh. Code § 312.5, subsections (a) and (d)(1). leginfo.legislature.ca.gov. Retrieved September 26, 2026.
- Georgia General Assembly. HB 454 (2019), amending O.C.G.A. § 40-1-1(15.3), as signed, published by the Office of the Governor. gov.georgia.gov. Retrieved September 26, 2026. "not more than 750 watts". Georgia's official compilation, published through LexisNexis, was not read.
- Kansas Office of Revisor of Statutes. K.S.A. 8-1489. ksrevisor.gov. Retrieved September 26, 2026. "less than 750 watts".
- Minnesota Office of the Revisor of Statutes. Minn. Stat. § 169.011 subd. 27. revisor.mn.gov. Retrieved September 26, 2026. "not more than 750 watts".
- Oklahoma Legislature. 47 O.S. § 1-104(B), "Electric-assisted bicycle." Title 47, complete. oklegislature.gov. Retrieved September 26, 2026. "not more than seven hundred fifty (750) watts".
- Alaska State Legislature. AS 28.90.990(a)(20)-(22). akleg.gov. Retrieved September 26, 2026. No electric-bicycle definition.
- Kentucky Legislature. KRS 189.010. apps.legislature.ky.gov. Retrieved September 26, 2026. No electric-bicycle definition.
- Redtail eBikes editorial desk. The 51-jurisdiction rule table and the FAT-HD 1.0 Pro screen. Every US state and DC, each row carrying its statutory citation; screened September 26, 2026 on the published 1000 W, 20 mph and thumb throttle: 4 qualify, 45 outside, 2 with no definition. First-party dataset.
- U.S. Consumer Product Safety Commission. SaferProducts recall database. saferproducts.gov/RestWebServices/Recall. Screened September 26, 2026 on the RecallTitle, RecallDescription and ProductName fields, each passing a control query the same minute; no recall names Eunorau or the FAT-HD.
- U.S. Consumer Product Safety Commission. Product safety warning listing (complete CSV). cpsc.gov. Read September 26, 2026: 373 warnings, 2 naming the control brand, none naming Eunorau, the FAT-HD or the Hunter X7; deposit copy and screen archived.
- Electric Bike Review. EUNORAU FAT-HD Review. Published March 19, 2019; specification block "Model Year: 2019". electricbikereview.com. Retrieved September 26, 2026; deposit copy archived. The 2019 build's price, pack, speed, weight, brakes, display, throttle and tire.
- UL Standards & Engagement (standards body; context only). UL 2849 and UL 2271. Retrieved August 29, 2026.
- Bafang. Workbook OEM 2021, MOTORS table, M615 (MM G320.750.C / MM G320.1000.C) column: rated voltage, n0, rated power, nT, maximum torque, efficiency and pedal sensor. bafang-e.com. Retrieved September 23 and September 26, 2026; deposit copy archived.
- Shimano. Exploded view EV-CS-HG200-7-3950A, CS-HG200-7 cassette sprocket: the bm-group teeth combination 12-14-16-18-21-24-28T. dassets.shimano.com. Retrieved September 26, 2026; deposit copy archived.
- Kenda. Juggernaut Sport (product listing: the 26x4.00 Sport, Pro and Elite casings). shop.kendatire.com. Retrieved September 26, 2026; deposit copy archived.
- Bicycle Rolling Resistance. Kenda Juggernaut Pro (fat-bike drum test, 12 psi, and the site's list of twelve current fat-bike tires). bicyclerollingresistance.com. Retrieved September 25, 2026.
- Martin, J. C., Milliken, D. L., Cobb, J. E., McFadden, K. L. and Coggan, A. R. Validation of a Mathematical Model for Road Cycling Power. Journal of Applied Biomechanics 14(3):276–291 (1998), Eq. 14 and Appendix I; doi 10.1123/jab.14.3.276. collections.lib.utah.edu. Retrieved September 23, 2026.
- Tengattini, S. and Bigazzi, A. Y. Physical characteristics and resistance parameters of typical urban cyclists. Journal of Sports Sciences 36(20):2383–2391 (2018), Table 4; doi 10.1080/02640414.2018.1458587. civil-reactlab.sites.olt.ubc.ca. Retrieved September 23, 2026.
- Arango, I., Lopez, C. and Ceren, A. Improving the Autonomy of a Mid-Drive Motor Electric Bicycle Based on System Efficiency Maps and Its Performance. World Electric Vehicle Journal 12(2):59 (2021), Eq. (40) and Fig. 5; doi 10.3390/wevj12020059. mdpi-res.com. Retrieved September 23, 2026.
- Kollmeyer, P. et al. LG 18650HG2 Li-ion Battery Data. Mendeley Data v2, McMaster University; doi 10.17632/b5mj79w5w9.2 (0.5C discharge files, recomputed). doi.org. Retrieved September 23, 2026.
- Samsung SDI. Specification of Product INR18650-35E, Ver. 1.1 (July 9, 2015), § 7.5 Temperature Dependence of Discharge Capacity. enerpower.de. Retrieved September 23, 2026.
- Casado, S. et al. Evaluation of commercial Li-Ion 18650 battery cells for deep space applications. Journal of Power Sources 638:236552 (2025), Table 3; doi 10.1016/j.jpowsour.2025.236552. doi.org. Retrieved September 23, 2026.
- NOAA, NASA and US Air Force. U.S. Standard Atmosphere, 1976 (NOAA-S/T 76-1562), sea-level pressure and the composition of dry air. ntrs.nasa.gov. Retrieved September 23, 2026.
- Rothhämel, M. On rolling resistance of bicycle tyres with ambient temperature in focus. International Journal of Vehicle Systems Modelling and Testing 17:67–80 (2023), Tables 1 and 4; doi 10.1504/IJVSMT.2023.132317. inderscience.com. Retrieved September 23, 2026.
- Hansen, E. A. et al. Freely chosen cadence during ergometer cycling is dependent on pedalling history. European Journal of Applied Physiology 121(11):3041–3049 (2021), Results; doi 10.1007/s00421-021-04770-w. pubmed.ncbi.nlm.nih.gov. Retrieved September 26, 2026.
- Marsh, A. P. and Martin, P. E. Perceived exertion and the preferred cycling cadence. Medicine and Science in Sports and Exercise 30(6):942–948 (1998), Results; doi 10.1097/00005768-199806000-00025. pubmed.ncbi.nlm.nih.gov. Retrieved September 26, 2026.
- U.S. Army Natick Soldier Research, Development and Engineering Center. 2012 Anthropometric Survey of U.S. Army Personnel (ANSUR II), public data release (4,082 men, 1,986 women). army.mil. Retrieved September 25, 2026.
- Peveler, W., Bishop, P., Smith, J., Richardson, M. and Whitehorn, E. Comparing Methods for Setting Saddle Height in Trained Cyclists. Journal of Exercise Physiology Online 8(1):51–55 (2005). asep.org. Retrieved September 25, 2026.
- Ferrer-Roca, V., Roig, A., Galilea, P. and García-López, J. Influence of saddle height on lower limb kinematics in well-trained cyclists: static vs. dynamic evaluation in bike fitting. Journal of Strength and Conditioning Research 26(11):3025–3029 (2012). pubmed.ncbi.nlm.nih.gov. Retrieved September 25, 2026.
- Peveler, W. W., Pounders, J. D. and Bishop, P. A. Effects of saddle height on anaerobic power production in cycling. Journal of Strength and Conditioning Research 21(4):1023–1027 (2007). pubmed.ncbi.nlm.nih.gov. Retrieved September 25, 2026.
- Priego Quesada, J. I. et al. Effect of bike-fit in the perception of comfort, fatigue and pain. Journal of Sports Sciences 35(14):1459–1465 (2017). pubmed.ncbi.nlm.nih.gov. Retrieved September 25, 2026.
- Slane, J., Timmerman, M., Ploeg, H. L. and Thelen, D. G. The influence of glove and hand position on pressure over the ulnar nerve during cycling. Clinical Biomechanics 26(6):642–648 (2011). pubmed.ncbi.nlm.nih.gov. Retrieved September 25, 2026.
- Carahalios, A. An Analysis of the Bicycle-Rider Interface Forces in Stationary Road Cycling. MS thesis, University of Colorado (2015). scholar.colorado.edu. Retrieved September 25, 2026.
- Clauser, C. E., McConville, J. T. and Young, J. W. Weight, Volume, and Center of Mass of Segments of the Human Body, AMRL-TR-69-70 (1969). ntrs.nasa.gov. Retrieved September 25, 2026.
- Redtail eBikes editorial desk. FAT-HD 1.0 Pro range model. The computation set out in the range section of this review, Martin et al.'s power model with Bafang's M615 figures; run September 26, 2026. First-party computation; every input and its source in its inputs table.
- Redtail eBikes editorial desk. FAT-HD 1.0 Pro fit model. The computation set out in the fit section of this review, for the ANSUR II bodies on the frame as Eunorau photographed it, the photograph's scale checked against Eunorau's table; run September 26, 2026. First-party computation; every input and its source in its inputs table.
- New Jersey Legislature. P.L.2025, c.285, amending R.S. 39:1-1, "Low-speed electric bicycle" and "Motorized bicycle"; approved January 19, 2026. pub.njleg.gov. Read September 26, 2026 through a proxy when the publisher timed out; the enacted text is also on file from August 15, 2026. "provides assistance only when the rider is pedaling".
Image credit: every photograph on this page is Eunorau's own. The cover and the card inside it are Eunorau's studio photograph of the Camo build, set on a studio floor and composited with type in real fonts; the side views, the geometry diagram and the close crops are Eunorau's product images.





















Share:
Eunorau META275 2.0 Review 2026: 720 Wh, $1,529
Eunorau FAT-HD 2.0 Review (2026): Step-Through, 375 lb