Eunorau DEFENDER-S 2.0 Review: Dual 750 W, 53 Miles

89.3 lb · 26 × 4.0 fat tires · 2 × 750 W hubs, front and rear · 85 N·m · four-bar frame, 75 mm fork, air shock · Shimano CUES 9-speed · 816 Wh · 20 mph Class 2 start, 28 mph maker setting · 300 lb payload · 17" or 19" frame · $2,799 · verified October 2, 2026

Quick Answer: The Eunorau DEFENDER-S 2.0 is a $2,799 dual-motor full-suspension fat-tire e-bike: a 750 W hub in each wheel, a four-bar frame with an air shock, nine Shimano CUES gears and 203 mm hydraulic brakes. On both motors a 180 lb rider covers about 53 miles at 12 mph on the throttle over level pavement.

Pick the frame by height: the 17-inch saddle range suits most riders up to 5'7", the 19-inch most from 5'4" to 5'10" (the fit section). Counted one motor at a time, its printed figures sit inside 28 of 51 jurisdictions' e-bike definitions on October 2, 2026; counted as one 1,500 W system, inside 3 (the law section).

What's on this page

Twenty-seven sections: who the DEFENDER-S 2.0 is for, its motors, suspension, parts and frames, Eunorau's other dual-motor bikes, the range and payload, your fit, the law at 20 and at 28 mph, ownership, and the verdict.

• Who the DEFENDER-S 2.0 is for
• How we verified this Eunorau DEFENDER-S 2.0 review
• Eunorau DEFENDER-S 2.0 specifications
• Two 750 W hubs and a torque sensor
• The four-bar suspension
• Nine gears, 203 mm brakes and the display
• Two frame sizes and the second battery
• DEFENDER-S 2.0 or another Eunorau with two motors
• How far the DEFENDER-S 2.0 goes on one charge
• What the 300 lb payload covers
• Will the DEFENDER-S 2.0 fit you?
• The Mercer fit test
• What the law calls it: two 750 W hubs, a throttle and 20 mph
• The 28 mph setting
• Charging and battery care
• Where Eunorau prints a figure two ways
• Recall and warning record
• Is it UL certified?
• Warranty, and who handles a 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 DEFENDER-S 2.0 is for

The Moon Black as Eunorau photographed it, placed on a light studio backdrop made for this card. Eunorau prints the $2,799 and the pair of 750 W hubs; the 53 miles come from the range section.

The DEFENDER-S 2.0 is for you if your riding leaves the pavement and keeps going: two-track to a deer stand, a gravel road out of town, sand, snow or a rutted trail. Eunorau's product record opens with "Built for challenging terrain and all-season exploration" (the record).

The Moon Black from the chain side, as Eunorau photographed it: a slate blue-gray in this light, with the air shock under the top tube and a hub in the front wheel.

The pitch Eunorau makes is in its headline, "Go Where One Motor Stops", with "All-wheel-drive traction, four-bar full suspension, and torque-sensing control" in one fat-tire bike (Eunorau's page). Its record tags the bike for "Hunting & Fishing", and the Dry Grass Camo colorway is cut for the same ground.

If you have read about the first Defender S, its numbers do not carry over. For the 2.0 Eunorau prints 89.3 lb, a 300 lb maximum payload, 203 mm rotors front and rear, a 48V 17Ah pack and a 20 mph Class 2 startup (Eunorau's specification, read October 2, 2026), and every figure on this page is the 2.0's.

Riding mostly pavement and want to spend less? Our FAT-AWD 2.0 review covers two 500 W hubs on a rigid-rear step-over for $1,699. Would rather step through than swing a leg over? Our FAT-AWD 3.0 review has the same pair on a step-through.

How we verified this Eunorau DEFENDER-S 2.0 review

Every specification is Eunorau's, read from the DEFENDER-S 2.0 page and its product record on October 2, 2026, and every figure that takes arithmetic is recomputed here. Where Eunorau's sources disagree, the conflicts table prints both.

The range and fit sections end with their formula and every input (range, fit). The law section screens all 51 jurisdictions four ways, and the Limitations date each read. We sell the DEFENDER-S 2.0, and the honest ledger points each rider it suits less well to another of our bikes. Milad Ghobadibeygvand, BScN (Western University, 2014), wrote it; corrections go to corrections@redtailebikes.com.

Eunorau DEFENDER-S 2.0 specifications

Eunorau's own figures, from the page and the record read October 2, 2026:

The Dimensions & Rider Fit table on the DEFENDER-S 2.0 page, both frames:

Read from the DEFENDER-S 2.0 page on October 2, 2026; the inch figures are Eunorau's. Row J runs from the crank axle to the saddle top (the fit section).

Two 750 W hubs and a torque sensor

A 48 V, 750 W hub motor turns each wheel, "1,500W of combined rated power", and a 48V 25A dual-motor controller runs the pair (Eunorau's page). A throttle moves the bike without pedaling, and Eunorau prints one torque figure, "85 N·m maximum torque".

The front wheel, cropped from Eunorau's front three-quarter photograph of the Moon Black: the hub motor sits at the axle behind the rotor, with the RST fork leg beside it.

When you pedal, a bottom-bracket torque sensor reads your effort. In Eunorau's words it "responds to pedaling effort rather than only crank movement. Lighter pressure produces gentler support, while harder pedaling calls for more assistance" (its FAQ).

Ask whether you can ride on one motor and Eunorau's FAQ answers that "The dual-motor control system is designed to manage motor operation for different conditions," and sends you to the manual for "the final production control labels and operating sequence" (its FAQ). This review models the pair driving together, the configuration Eunorau describes.

What the second hub buys you, in the model: up an 8% grade the pair holds 18.4 mph with 180 lb aboard and 17.6 mph with the full 300 lb, and a 12% grade at 17.6 mph and 14.0 (the climb table). Brake levers carry "motor cut-off sensors", so either lever stops the drive.

The four-bar suspension

Both ends of the DEFENDER-S 2.0 move: an RST GUIDE fork with 75 mm of travel up front, and an AOS01 air shock, 165 mm eye-to-eye, working a four-bar rear linkage (Eunorau's record). Eunorau's page says the system helps "isolate impacts and keep the wheels tracking across broken ground."

The middle of the frame, cropped from Eunorau's chain-side photograph: the rocker link drives the air shock, which sits under the top tube ahead of the seat post.

The fork adjusts for preload and locks out, in the page's words "75mm travel, preload and lockout", so you can firm the front for a long climb on a graded road. The shock is "adjustable", and an air shock is set by its pressure: set it for your weight with gear before the first ride off the pavement.

Fat tires do part of the same work. At low pressure a 26 × 4.0 tire flattens over roots and gravel, and Eunorau's own tip is to "Adjust speed and tire pressure for the conditions" (its FAQ).

Nine gears, 203 mm brakes and the display

You shift nine speeds on Shimano's CUES group: an SL-U4000-9R RAPIDFIRE PLUS shifter, an RD-U3020-SGS rear derailleur and a CS-LG300-9 cassette, 11 to 36 teeth, driven by a 42-tooth chainring on 170 mm cranks (Eunorau's record).

The rear wheel, cropped from the chain-side photograph: the nine-cog cassette and derailleur on the rear hub, and the stays of the four-bar rear.

Hydraulic discs stop both wheels on 203 mm rotors, and "Integrated motor cut-off sensors immediately interrupt motor assistance when either brake lever is engaged" (Eunorau's record).

The cockpit, cropped from Eunorau's front three-quarter photograph of the Army Green: the riser bar and levers, the stem, and the headlight on its bracket.

The rest, as Eunorau lists it:

• The display: MINI TOUCH, color, with Bluetooth, for "pedal-assist and speed settings".
• The bar and stem: a 700 mm riser bar with 25 mm of rise, an adjustable alloy stem, 130 mm lock-on grips.
• The lights and horn: an LED headlight with a horn up front and a red reflector at the rear.
• The wheels: 26-inch rims laced with 12-gauge, 36-hole spokes under 26 × 4.0 fat tires.
• The stand and pedals: an adjustable aluminum kickstand and 9/16" folding pedals.

Two frame sizes and the second battery

The same bike comes in a 17-inch and a 19-inch frame, at the same $2,799. Eunorau's table separates them by 51 mm of seat tube, 50 mm of saddle range, 10 mm of reach and 3 mm of stack; the wheelbase grows from 1,306 to 1,316 mm.

The Dry Grass Camo, photographed by Eunorau from the chain side: an orange-and-brown camouflage over the same four-bar frame.

At 89.3 lb it is a two-person lift into a truck bed, so plan on a ramp or a hitch rack rated for the weight. It runs 2,042 mm (80.4 in) long on the 17-inch frame (Eunorau's row H).

A second pack nearly doubles the energy, to 1,536 Wh. The DEFENDER-S 2.0 page lists the "EUNORAU Universal 48V15Ah Secondary Battery" among its compatible accessories, and that pack's own listing gives its weight as 9.9 lb; ours is $598.80.

The frame you pick decides how the second pack rides. The pack's listing names "DEFENDER-S 19"" plainly and "DEFENDER-S 17" (*Lock out rear shock to use)". If you plan to carry two packs often, that line is a reason to choose the 19-inch frame, and if your height puts you on the 17-inch, read the shock note in the pack's listing before you order it.

The Army Green, in Eunorau's chain-side studio photograph: an olive finish on the same frame and parts.

DEFENDER-S 2.0 or another Eunorau with two motors

Four Eunorau bikes on our shelf put a motor in each wheel, and the DEFENDER-S 2.0 is the one of them with a rear shock. The FAT-HS adds a fifth row for a full-suspension bike on one mid-drive.

Each row comes from that model's page at Eunorau (FAT-AWD 2.0, FAT-AWD 3.0, FLASH AWD 1.0, FAT-HS), read September 26 and 30, 2026; our prices were read October 2, 2026.

Pick the DEFENDER-S 2.0 when rough ground calls for a rear shock as well as two driven wheels. Pick the FAT-AWD 2.0 to save $1,100 and carry 375 lb on a rigid rear, the FAT-AWD 3.0 to step through, the FLASH AWD 1.0 for a passenger bench and 440 lb, and the FAT-HS for full suspension on one mid-drive. Our Eunorau collection holds all five.

The Moon Black from behind, photographed by Eunorau: the rear hub motor behind its rotor, the reflector under the saddle, and the side stand down.

How far the DEFENDER-S 2.0 goes on one charge

On the 816 Wh pack, both hubs on the throttle and a 180 lb rider aboard, the DEFENDER-S 2.0 covers about 53 miles at a steady 12 mph over level pavement, about 37 at 18 mph and about 32 at its 20 mph Class 2 limit.

Hold the 15% Eunorau suggests leaving in the pack and those plan as 45, 31 and 28. Add the optional 15 Ah second pack, 1,536 Wh in all, and a 12 mph day plans at 85 miles.

Behind every table in this section is one saved model of this bike, built on the figures Eunorau prints: a 48 V, 750 W hub in each wheel, 85 N·m, the 48V 17Ah pack, 89.3 lb, 26 × 4.0 tires and the 20 mph startup setting. The formula shows every input and the physics.

Your ride, in three reads:

1. Pick your pace in the speed table. 12 mph is a relaxed trail or farm-road cruise, 18 mph a brisk ride on a road shoulder.
2. Then correct it for your load and your ground with the weight rows, which run from 100 lb to the 300 lb rating, and the hill tables, which run from 2% to 15%.
3. Plan from the "15% kept" figures, since Eunorau's battery advice is to stop with 10 to 15% left.

How far does it go at my speed?

Pace decides more than anything else you control: 65 miles at 8 mph shrinks to 32 at 20 mph on the same charge. The air's drag grows with the square of speed, so the power it takes grows with the cube (Martin et al., 1998), and riding at 20 mph where you could ride at 15 gives up 27% of the miles.

Both hubs on the throttle, a 180 lb rider, level pavement and still air at 77 °F. The "15% kept" column leaves Eunorau's upper figure in the pack; the right-hand column adds the 15 Ah second pack for 1,536 Wh.

Pedaling stretches it furthest. The hubs drive the wheels whether you pedal or not, so every watt your legs add is a watt the pack keeps:

Both hubs and the 816 Wh pack, a 180 lb rider on level ground. Easy pedaling is 75 W at the cranks, steady is 150 W; "legs alone" means your 150 W holds that pace with no help from the motors.

To hold 12 mph the wheels need 126.2 W (Martin et al., 1998). Give 75 W of it yourself and the hubs cover the gap on 8.7 Wh a mile, which carries you 94 miles; give 150 W and you hold the pace with the hubs idle. On legs alone the same equation moves you and the 89.3 lb bike at about 9 mph on 75 W and about 13 mph on 150 W.

Which gear saves battery?

The nine gears set how fast your legs turn; the motors sit in the wheel hubs and never see the gears. What saves the pack is the effort you put in: at 12 mph on the flat it cuts the cost from 15.4 Wh a mile to 8.7, and at 12 mph up a 4% grade from 41.6 to 33.7.

Watt-hours drawn from the 816 Wh pack for each mile, both hubs, a 180 lb rider, still air. At 150 W you carry the flat at 12 mph yourself and the motors draw nothing.

Drop to an easier gear before a climb so your cadence stays smooth while the bike slows. The 42-tooth chainring and Shimano's 11–36T CUES cassette (Eunorau's drivetrain rows) give you a low gear to push in while the hubs do the heavy part.

What do hills cost, and how steep a hill can it hold?

Every 1,000 feet you climb on the throttle at 10 mph costs about 125 Wh on a 4% grade and about 144 Wh on a 10% grade, beyond what the same ground would cost flat. Lifting a 180 lb rider and the 89.3 lb bike through 1,000 feet takes about 101 Wh at the wheels; the hubs and the pack lose the rest to heat.

Both hubs, the 816 Wh pack, a 180 lb rider holding 10 mph up each grade in still air.

The fastest pace each grade allows on the throttle:

Both hubs on the throttle in still air, the 89.3 lb bike plus the load named in each column, each hub held to 85 N·m. Each cell is the top steady speed the modeled pair can hold on that grade.

This is where two driven wheels earn their place: up a 12% grade the pair holds 17.6 mph with 180 lb aboard and 14.0 mph with the full 300 lb. On loose ground the front hub pulls while the rear pushes, which is the "traction on loose, soft, or uneven surfaces" Eunorau describes.

Does my weight change the range?

It does, and most on climbs: at 12 mph on the flat, 180 lb of rider and gear gets 53 miles and the full 300 lb gets 45. Up an 8% grade at 10 mph the gap opens wider, 16 miles for a 100 lb load against 7 for 300 lb.

Rider and gear on the 89.3 lb bike, both hubs, the 816 Wh pack, still air.

Does cold weather drain the battery?

Yes: the 53-mile ride at 12 mph shrinks to about 43 miles at 32 °F and about 39 at 14 °F. At freezing the cells give back about 89% of their 77 °F energy, the air is 9% denser and the tires roll 18% harder (Rothhämel, 2023).

12 mph on the throttle with both hubs, 180 lb aboard, level pavement, the 816 Wh pack. The central figures use McMaster University's measured LG HG2 cell held at the air's temperature; at 32 °F and 14 °F each bracket spans the other published cell data (Limitations).

Eunorau names snow among the DEFENDER-S 2.0's ground, beside "pavement, gravel, sand, snow, and uneven trails" (its FAQ), so for a winter hunt, read your miles from the 32 °F and 14 °F rows.

Do the tires cut range?

Less than your speed does: across the fat tires Bicycle Rolling Resistance measured, the 12 mph ride runs from 49 to 61 miles, 53 at the median. Eunorau prints the size, "26 × 4.0-inch fat tires", and no tread or casing name, so the model takes the median of the ten 26 × 4.00 tires on the lab's drum, with the fastest and slowest as the bracket.

Level pavement, 180 lb aboard on the throttle with both hubs, the 816 Wh pack. The lab rolled each tire at 12 psi under 42.5 kg at 29 km/h, and the first column converts its watts to a rolling-resistance coefficient.

Eunorau's 40 and 80 miles, as rides

Eunorau prints "Up to 40 miles / 64 km" on the standard pack and "Up to 80 mi / 128 km combined" with the optional second battery (Eunorau's page). In this model a 180 lb rider on level ground in still air covers 40 miles at a steady 16.7 mph on the throttle, or 19.8 mph pedaling easily alongside.

With the 15 Ah second pack, Eunorau's 80 miles comes at a steady 15.7 mph on the throttle, or 19.1 mph with easy pedaling. Eunorau's FAQ adds that "Actual range varies with rider weight, terrain, speed, assist level, temperature, tire pressure, and riding style" (its FAQ).

How the range tables are computed

Each row begins with the power the wheels need at one steady speed, from the road-power equation Martin and colleagues checked against riders on real roads in 1998:

Wheel power = v × [ m × g × (Crr × cos θ + sin θ) + ½ × ρ × CdA × v² ]

In it, v is speed; m is the rider, gear and bike together; g is gravity; θ is the grade's angle; Crr is rolling resistance, where 0.0105 means a drag equal to 1.05% of the weight on the tires (the drum median); ρ is the air's density; and CdA is the drag area of rider and bike.

From the wheels back to the cells, four steps:

1. Your pedaling reaches the rear wheel through the chain at 97.7% (Martin et al., 1998); the two hubs supply the rest.
2. Each hub follows the curve of a hub motor whose figures are published, Bafang's RM G0H0: 510 rpm unloaded, 426 rpm at its rated point, "≥ 80" percent efficient, here wound for 48 V and 750 W. The two share the torque equally. Their unloaded speed is fitted at 20.9 mph, so that the pair carries a 180 lb rider on the throttle to Eunorau's 20 mph and no faster, and each is capped at 85 N·m.
3. The pack turns some energy to heat on its own: on the 48 V pack Arango, Lopez and Ceren measured, 3.1% at 12 mph on the throttle.
4. Watt-hours per mile are the cells' watts divided by the speed, and miles are the 816 Wh, less any cold loss, divided by the watt-hours per mile.

One ride worked through, wheel to cells: 180 lb aboard, both hubs on the throttle at 12 mph, level pavement. The tires take 67.7 W and the air 58.5 W, so the wheels need 126.2 W, and a 30.01-inch wheel turns 134.4 times a minute.

Each modeled hub (1.960 N·m per amp, 0.405 Ω, and 0.83 A unloaded, from Bafang's published figures wound for 48 V and 750 W) carries half the load; together they turn out 9.0 N·m on 6.2 A, 70% efficient at so light a load.

The hubs draw 179.6 W between them, and with the pack's own losses the cells give up 185.4 W, 15.4 Wh a mile. Unrounded that is 15.45, so 816 ÷ 15.45 comes to 52.8 miles, or 44.9 with 15% kept.

Checked against the figures the model was built from:

Martin and colleagues' Appendix I (90 kg on a 0.3% grade at 8.36 m/s), the RM G0H0's rated point in Bafang's workbook, and the two-hub arithmetic in the model's own selftest.

What the 300 lb payload covers

Eunorau rates the DEFENDER-S 2.0 for a "Maximum payload 300 lb / 136 kg, including rider and cargo" (its specification). You and everything you carry on the bike count against the 300 lb; the bike's own 89.3 lb does not.

Picture a 200 lb hunter with a 50 lb pack and the 9.9 lb second battery, about 260 lb, comfortably inside the rating. On both motors at 12 mph the weight table gives that load about 47 miles per pack (the weight table), and the pair still climbs a 12% grade at 15.3 mph (the climb table).

The Dry Grass Camo from the front, in Eunorau's studio photograph: the front hub motor and rotor, the fork and the headlight.

Weigh what you carry before the first trip out, and keep you, your pack, your rifle or bow case and any bolted-on gear inside Eunorau's 300 lb. For loads that belong behind the bike, Eunorau lists trailers among the DEFENDER-S 2.0's compatible accessories, and we stock the hunting trailer at $442.80 and the two-wheel hunting trailer at $394.80.

The rack and fender set Eunorau makes for the FAT-HS, DEFENDER-S and FAT-AWD 2.0 is $178.80 here, and it adds a place to strap gear.

Will the DEFENDER-S 2.0 fit you?

Choose the frame by your height: the 17-inch saddle range reaches the fit formula's height for most riders from 5'0" to 5'7" (73 of 100 at 5'7"), and the 19-inch for most from 5'4" to 5'10" (79 of 100 at 5'10"). Below about 5'5", the 17-inch's top tube is the number to check: 68 of 100 riders at 5'4" clear it standing barefoot.

In the rows where each frame fits, you lean about 23 to 27 degrees toward the grips, and with your back relaxed your hands carry about a fifth of your weight.

Each figure comes from the 6,068 bodies in the US Army's anthropometric survey, with the saddle at 109% of inseam from the pedal axle, on the 17-inch frame as Eunorau photographed it and the 19-inch from Eunorau's printed differences.

Three steps to your size:

1. Measure your inseam in bare feet. Stand against a wall, draw a hardcover book up firmly between your legs where a saddle would sit, and measure from the floor to the book's top edge.
2. Find your height in both saddle tables and confirm your inseam falls inside that row's range; a longer inseam behaves like the row above.
3. Order the frame whose row reads higher for you, then set the saddle on arrival with the knee and heel checks near the end of this section.

Eunorau prints a window for the 17-inch and leaves the 19-inch blank on the product page. The product page's Dimensions & Rider Fit table gives "Recommended height 160-193cm / —": 5'3" to 6'4" for the 17, and a dash for the 19.

Eunorau's frame-size guide puts a 17-inch frame where its 5'2"–5'6" row meets its 5'6"–5'10" row, and a 19-inch where the 5'6"–5'10" row meets the 5'10"–6'1" row. The tables below sit closer to the guide: from about 5'9" up, most riders' saddle height runs past the 17-inch frame's top setting.

How high should the saddle go?

Set the saddle 109% of your inseam above the pedal axle; on the 17-inch frame Eunorau's seat range covers that for 99 of 100 riders at 5'2" and 5'4", 83 at 5'6" and 14 at 5'10". Published practice runs from 106% to 110.4% of inseam (Ferrer-Roca et al., 2012), and 109% is the figure Peveler and colleagues checked against knee angle in trained cyclists.

Eunorau prints the range as "J: Seat height 585-735mm" on the 17 and "635-785mm" on the 19, measured from the crank axle to the saddle top: its photograph of the 17-inch frame shows the saddle 633 mm from the crank axle, inside the 17's range.

Along a seat post leaning back at 73.1 degrees from a crank axle 13.4 inches up, with Eunorau's 170 mm cranks, that puts the 17-inch saddle 35.7 to 41.4 inches off the ground and the 19-inch 37.6 to 43.3.

Ground-to-saddle height the 109% formula gives the median rider at each height, and how many riders of 100 at that height can set it inside the 17-inch frame's 35.7 to 41.4 inches, at 109% and at 106%. ANSUR II bodies, women and men pooled.

The same rows on the 19-inch frame's 37.6 to 43.3 inches: Eunorau's 635-785 mm placed along the same post as the 17-inch's.

At 5'10" the 17-inch saddle stops a median of about 1.3 inches short for riders whose formula height it misses, and at 6'0" about 2.4 inches, which is why the 19-inch takes over there. On the 19-inch, the shortfall at 6'2" is about 1.8 inches; if you are 6'2" or taller, the seat post's length is the question to settle before you order.

Eunorau's drawing labels its own J line differently, from the ground to the saddle top (the conflicts table), and the record lists the post as "31.6 × 280mm aluminum".

Can I put a foot down at a stop?

On the 17-inch frame, standing astride at a stop, 27 of 100 riders at 5'2" clear the top tube barefoot, 68 at 5'4" and 96 at 5'6". Eunorau prints no standover, so the top tube's upper edge is read on its photograph, 2 inches ahead of the saddle's nose, at 30.1 inches.

Riders of 100 at each height whose barefoot inseam clears the 17-inch frame's top tube at 30.1 inches. Shoes add some height; if you do not clear it, you lean the bike to one side to put a foot down.

The 19-inch frame's top tube stands higher by an amount Eunorau does not print, so read this table as the 17-inch's alone. Under about 5'5", the 17-inch is the frame to ask us about, and the FAT-AWD 3.0 puts two hubs on a step-through you never swing a leg over.

Eunorau's own geometry drawing, from the DEFENDER-S 2.0 page. Its letters are not the table's letters: on the drawing, J runs from the ground to the saddle top and G drops from the top tube to the ground.

Will I feel cramped, or stretched out?

Expect a sporty lean: on the 17-inch frame the median rider tips 23 degrees from vertical at 5'0" and 25 at 5'8" to reach the grips. On Eunorau's photograph the grips sit 20.5 to 22.2 inches ahead of the crank axle and 29.9 to 32.1 inches above it, and the 19-inch adds Eunorau's extra 10 mm of reach and 3 mm of stack.

Lean from vertical for the median rider on the 17-inch frame as photographed: the smallest trunk angle at which a straight arm reaches the grips from where the sit bones rest, across the saddle's sit zone and the grip's extent.

On the 19-inch frame the saddle rides higher for the same rider, so the lean grows a little: the median rider leans 27 degrees at 5'10" against 24 on the 17-inch. Eunorau's page lists an "Adjustable alloy stem", which brings the grips up toward you if you want to sit taller.

How much weight goes on my hands?

With your back relaxed, the median rider's hands carry about 18 to 19% of body weight on the 17-inch frame from 5'0" to 5'8", and 19 to 21% on the 19-inch from 5'4" to 6'0". For scale, ten road racers riding on the hoods put 15% of their weight on the stem (Carahalios, 2015).

The share of body weight your hands carry with a relaxed back on the 17-inch frame, from each body's segment weights (Clauser et al., 1969); the span covers the sit zone and the grip's extent, and the weight column is the survey median for that height.

A trunk you hold up yourself takes part of that load, so read each row as the ceiling. Raising the adjustable stem lowers it, and on long days padded gloves help: across 36 experienced cyclists they cut pressure over the ulnar nerve by 10 to 28% (Slane et al., 2011).

How do I set the saddle when it arrives?

Aim for your knee bent 25 to 35 degrees with the pedal at the bottom of its stroke (Peveler et al., 2007). The heel check gets you there fastest: heel on the low pedal, raise the saddle until that leg just goes straight. In 19 trained cyclists it put 70% inside the knee range, more than either inseam formula (Peveler et al., 2005).

Hold the bike upright, open the post's quick-release clamp, set the height by the heel check, and close the clamp firmly before you ride.

How we computed fit

Three rules make every fit row: the saddle sits 1.09 inseams above the pedal axle, the lean is the least trunk angle that lets a straight arm meet the grip, and the hand load is the share of upper-body weight that lean puts on the bars.

A worked case: you are 5'8" with a 32.6-inch inseam, the survey's median at that height. Your saddle goes 35.6 inches from the pedal axle, 28.9 from the crank axle once the 170 mm crank comes off (LeMond's 88.3% of inseam gives 28.8).

Up this frame's 73.1-degree post from a crank axle 13.4 inches off the ground, that is a saddle top 41.3 inches up, just inside the 17-inch frame's 41.4-inch top.

The photograph is Eunorau's Moon Black from the drive side, the first image in its gallery, with both tires fitting circles of nearly the same size on a level line. Before a single point was read, its scale was checked against Eunorau's table for the 17-inch frame.

Scale from the 17-inch column's 51.4-inch wheelbase, axle center to axle center. The total length, chain stay and seat tube land within 3.5%, and so does the effective top tube Eunorau calls "G: Top tube" (645 mm, read 25.2 inches on the photograph); the bracket, stack, reach and head tube read 4.8 to 6.8% off, and Eunorau's own drawing disagrees with its table on those too.

The photographed seat tube is a 17-inch: it reads 17.6 inches to the top of the clamp ring, and 16.7 to the tube's own top, against the 17 column's 17 inches and the 19 column's 19. Over all 6,068 bodies, LeMond's route plus a 170 mm crank works out to 109.0% of inseam from the pedal, beside the 109.2 ± 0.9% measured in trained cyclists (Peveler et al., 2005).

The Mercer fit test

Each bike we review meets one family, the Mercers, and every verdict here rests on a figure Eunorau prints or on the fit model's row for that height.

The inputs: the 17-inch saddle at 35.7 to 41.4 inches off the ground and the 19-inch at 37.6 to 43.3, the 17-inch top tube at 30.1 inches, the 300 lb payload, the 89.3 lb weight, and the law in the next section.

For the Mercers the line falls between 5'6" and 5'7": Ruth and Maya ride the 17-inch, everyone from Dana up rides the 19-inch, and Jack confirms his inseam with us before ordering.

What the law calls it: two 750 W hubs, a throttle and 20 mph

The DEFENDER-S 2.0 was screened against the e-bike definitions of all 51 jurisdictions on October 2, 2026, and the answer depends on how its two hubs are counted. One motor at a time, its printed 750 W, throttle and 20 mph sit inside 28 definitions; counted as one 1,500 W system, inside 3.

Eunorau prints both counts: "Dual 48V 750W hub motors" and "Combined rated power 1,500W" (Eunorau's page). Read your own state's definition with both numbers in hand.

Counted per motor, a 750 W hub meets the wattage line where a state writes "not more than" or "does not exceed" 750 watts, and misses it in the 19 that write "less than" or "fewer than". A 750-watt motor is not less than 750 watts.

California is one of the first kind: its definition asks for "an electric motor that does not exceed 750 watts of power" (Cal. Veh. Code § 312.5(a)), which each hub meets and the pair together does not.

Two more fall outside on the per-motor reading. Pennsylvania takes in a vehicle "manufactured or assembled with an electric motor system rated at not more than 750 watts" (75 Pa.C.S. § 102), and two 750 W hubs make a 1,500 W system.

New Jersey's motor may assist only while you pedal, which leaves a throttle out. Alaska and Kentucky have no e-bike definition at all (our state guide links each state's page).

Counted as one 1,500 W system, the DEFENDER-S 2.0 fits only the three definitions that set no wattage:

Where two 750 W hubs with a throttle at 20 mph, counted as one 1,500 W system, sit inside the definition on October 2, 2026: 3 of 51 jurisdictions, each quoted from its statute through our 51-jurisdiction rule table.

Rhode Island writes its cap in horsepower, "two (2) (S.A.E.) horsepower" (R.I. Gen. Laws § 31-1-3(g)), about 1,492 W, so the per-motor reading clears it and the 1,500 W system does not. A word search of the 51 definitions we hold found wording on more than one motor only in Pennsylvania's "electric motor system" (Limitations).

Where a bike falls outside a state's definition, that state's code governs it as another vehicle, and the statute behind each row names which. Every state's own page is linked from our state guide.

The 28 mph setting

Eunorau's highlights call the bike "Class 2 Speed limited Unlockable", and its record lists a "Power-On Setting: Manufacturer-defined Class 2 mode" up to 20 mph and a "Manufacturer-Defined Class 4 Setting: Up to 28 mph / approximately 45 km/h" (Eunorau's record). The product FAQ closes its speed answer with "Follow local regulations."

At 28 mph with a throttle, the DEFENDER-S 2.0 sits inside none of the 51 definitions, counted per motor or combined. In our 51-jurisdiction rule table, every definition that allows a throttle stops it at 20 mph; Oregon's Class 2, for one, is a bicycle that "Ceases to provide assistance once the bicycle reaches a speed of 20 miles per hour" (ORS 801.258).

On any public road, path or trail, leave the bike at its Class 2 start. The 20 mph figures on this page, the range tables included, are all at the setting Eunorau's specification calls the "Default startup mode".

Charging and battery care

Eunorau ships a 54.6V 2A charger and prints "Approximately 6–8 hours" for a full charge (its record). A typical outing asks far less: 20 miles at 12 mph on both motors draws about 309 Wh from the cells (the speed table), a little over a third of the pack.

Eunorau's general FAQ says to recharge with 10 to 15% left, and to store a pack you will not use for more than two weeks "in a cool, dry place with a 70%-80% charge remaining". It says its batteries "typically last 5-6 years" and keep "more than 80% of their original capacity after 500 charge cycles".

Where Eunorau prints a figure two ways

Eunorau describes the DEFENDER-S 2.0 on its product page, in its product record, on a lettered geometry drawing and in the second pack's listing. Where two of them part ways, the right-hand column names the figure this review uses.

The page and record were read October 2, 2026, the second pack's listing and Eunorau's warranty and FAQ pages the same day; the warranty and FAQ text had not changed since September 26.

Recall and warning record

No federal recall names Eunorau, the DEFENDER-S or the Hunter X6. On October 2, 2026 the CPSC's recall database returned no recall for "Eunorau" in the title, description and product name fields, each shown working by a control query, and none of the 51 recalls whose titles name an electric bicycle, an e-bike or an electric scooter names it.

The database's model-name queries returned a server error that morning, so we read all 10,027 recalls it lists, June 8, 1973 to September 24, 2026, word by word. "Defender" appears in 8 of them, on Can-Am Defender side-by-side vehicles, doorknobs, pool covers, chin straps and an insect-trap part, and "Hunter X6" in none.

The same morning we read all 373 rows of the CPSC's product safety warning listing: two matched the control brand, and none named Eunorau, the DEFENDER-S or the Hunter X6.

Is it UL certified?

Eunorau's DEFENDER-S 2.0 page shows "UL CERTIFIED Yes" in its highlights. Two standards stand behind a mark like that: UL 2849 for an e-bike's whole electrical system and UL 2271 for the battery pack alone. If your landlord, building or insurer wants the certificate itself, say so with your order and we will request it from Eunorau.

Warranty, and who handles a claim

Read October 2, 2026, Eunorau's warranty policy sets a term for each part:

The policy, issued by "Eunorau Bikes, a Nevada corporation", covers manufacturing defects in bikes bought in the US from August 1, 2023 (the policy). It asks for proof of purchase, "Product Registration right after the purchase", an "E-bike check-up by a Eunorau specialist or dealer after the first year of use", and that you are the original purchaser.

Buy your DEFENDER-S 2.0 from us and we run the claim. Email us a photo and a line on what failed, and we work with Eunorau until the part reaches you. Our Eunorau brand profile sets these terms side by side across the range.

Buying it from us

The value case in numbers. Our listing on October 2, 2026 split the $2,799 into 12 payments of $252.63, 6 of $487.12 or 3 of $956.42, each at 15% APR.*

*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.

Torn between the 17 and the 19, or between this and a FAT-AWD? Email your height, barefoot inseam, state, what you carry and the ground you ride to support@redtailebikes.com, and we will tell you which frame and which bike.

The honest ledger

Green flags

• A 750 W hub in each wheel: up a 12% grade the pair holds 17.6 mph with 180 lb aboard and 14.0 mph with 300 lb (the climb table).
• Full suspension: a 75 mm RST GUIDE fork with preload and lockout and a 165 mm air shock on a four-bar rear (the suspension section).
• An 816 Wh pack, with a 15 Ah second pack listed: about 53 miles at 12 mph on one pack for a 180 lb rider, and 85 planned on two (the range tables).
• Nine Shimano CUES gears, 11 to 36 teeth, so your legs have a gear on any climb (the parts section).
• 203 mm hydraulic rotors at both ends, each lever cutting the motors (the parts section).
• Two frames at one price, the 17-inch for riders up to 5'7" and the 19-inch from 5'4" to 5'10" in the fit tables (the fit section).
• Eunorau's own $2,799 on October 2, 2026, in every color and frame (buying from us).

Red flags: where it is the wrong bike, and what to do

• You ride mostly pavement and want to spend less: the FAT-AWD 2.0 puts two 500 W hubs on a rigid rear for $1,699 and carries 375 lb (our FAT-AWD 2.0 review).
• You are under about 5'4" and need a low frame to stand over: the FAT-AWD 3.0 is a step-through with two hubs (our FAT-AWD 3.0 review); or check your row in the standover table.
• You and your gear total more than 300 lb: the FLASH AWD 1.0 is rated for 440 lb on two 750 W hubs (our FLASH AWD 1.0 review).
• You are 6'2" or taller: the 19-inch saddle reaches 8 of 100 riders at 109%, so email us your inseam before ordering, and read the saddle tables.
• Your state counts two motors together: read your state's page in our state guide first; the FAT-HS gives you full suspension on one motor (our FAT-HS review).

Who should buy it

Buy the DEFENDER-S 2.0 if you want two driven wheels and full suspension for gravel, sand, snow, trails and climbs, nine gears, 203 mm brakes, room for 300 lb and a second pack, and a state whose definition takes in its motors, for $2,799.

Choose the FAT-AWD 2.0 instead if a rigid rear is fine and $1,100 matters, the FAT-AWD 3.0 to step through, and the FLASH AWD 1.0 for a passenger or a load past 300 lb.

Hold off if your state counts two motors as one system and you want to ride as an e-bike there; the FAT-HS has full suspension on one motor.

Before you buy: the checklist

Eight checks: four that settle the bike and the frame, four for the order and the first week.

• ☐ Read your state's e-bike definition for two things: whether it counts two motors together, and whether it writes "less than" or "not more than" 750 watts; start at our state guide.
• ☐ Measure your barefoot inseam and find your row in both saddle tables: 17-inch below about 5'7", 19-inch from about 5'7".
• ☐ Total your weight, your gear and any second pack against the 300 lb; the bike's 89.3 lb is not part of it.
• ☐ Measure where you will park it for a bike of 89.3 lb and 80 inches long, and plan a ramp for any steps.
• ☐ Work out your longest ride at 12 mph on both motors: one pack plans 45 miles for a 180 lb rider on the flat, two plan 85.
• ☐ If you will run two packs on the 17-inch frame, read the pack listing's line on locking out the rear shock first.
• ☐ Give the pack a full charge before the first ride: Eunorau lists 6 to 8 hours on its 54.6V 2A charger.
• ☐ Look the box over while the carrier is still there, and email us photos within 48 hours of any damage you find.

Limitations of this review

Twenty-two limits on this review, numbered and tied to the section each one qualifies.

1. The specifications are Eunorau's, from its page, record, geometry drawing, second-pack listing and FAQs, recomputed wherever arithmetic enters. The range and fit models, the four jurisdiction screens, the recall reads and our store terms are ours, each explained below.
2. Every range row is one steady speed on one grade in still air. Stops, starts and headwinds cost more; a tailwind costs less.
3. Eunorau prints the speed, the seat height's datum, the geometry letters, the rider height, the fork adjustment, the stem, the rims and the warranty more than one way (the conflicts table); the review uses the figure named there.
4. The screens set the printed 750 W per motor and the 1,500 W combined, with the throttle, beside each definition at 20 mph and at 28 mph as our rule table and the statutes stood on October 2, 2026, with Eunorau's 89.3 lb for Pennsylvania's weight limb. They read the motor, speed, throttle and weight limbs, leave age, helmet and passenger rules to each state, and are not legal advice.
5. The per-motor count is 29 in the screen's own table and 28 here, because Pennsylvania rates the whole "electric motor system", which the table's per-motor run does not apply. The screens read each definition's motor, speed, throttle and weight limbs as printed, and Eunorau's "Unlockable" label is quoted as it appears and screened at both of its printed speeds.
6. A word search of the 51 definitions we hold, for wording on more than one motor ("motor system", "motors", "combined", "one or more", "total", "aggregate"), found only Pennsylvania's "electric motor system"; a search for words is a floor, not a reading of every clause.
7. Connecticut's definition changed on October 1, 2026, from "fewer than" to "not more than" 750 watts (P.A. 26-24 § 26), and the screens read it at the new wording.
8. The recall reads ran on October 2, 2026. The three brand fields each passed a control query; the model-name queries returned a server error, so the full list of 10,027 recalls was read instead, every field, matched on whole words. A title search is a floor, and the warning listing's 373 rows were read the same day.
9. Our price, orderability and Shop Pay terms come from our own listing, read October 2, 2026; the payments are its plan table for $2,799 at 15% APR.
10. The motor model rests on a comparable hub's published curve, Bafang's RM G0H0, one per wheel, wound for 48 V and 750 W, with the unloaded speed fitted so two hubs carry a 180 lb rider to Eunorau's 20 mph and no faster. Eunorau does not name the hubs or say whether they are geared.
11. Eunorau prints one torque figure, "85 N·m", without saying whether it is each hub's or the pair's. The model caps each hub at 85 N·m. Read as the pair's, 42.5 N·m a hub, the model changes one cell: 300 lb up a 12% grade no longer holds on the throttle alone, and every other range figure on the page stays the same.
12. The model splits the torque equally between the hubs and does not model the 48V 25A controller's current limit; if the controller caps current below what two hubs draw on a steep climb, the climb speeds run lower.
13. No drum or road figure for the DEFENDER-S 2.0's tire was found, so the model uses the median of ten 26 × 4.00 fat tires on Bicycle Rolling Resistance's drum, bracketed by the slowest and fastest of the ten.
14. The model's wheel is the nominal 26 × 4.0 diameter, 30.01 inches, and its drag area the upright cruiser figure of 37 everyday riders; the photograph's tires measure 28.9 inches.
15. The cold rows use McMaster's measured LG HG2 cell as the central line, bracketed by Samsung's 35E data sheet and Casado et al., 2025; Eunorau names "high-capacity cells" in the record and Samsung cells in the second pack's listing.
16. The two-pack column uses the 15 Ah pack the DEFENDER-S 2.0 page lists among its accessories and leaves out the pack's 9.9 lb; Eunorau's "80 mi" line names no capacity for the optional battery.
17. No ride of the DEFENDER-S 2.0 to empty, with its speed and load stated, was found in print, so the chain from wheel to pack is checked link by link against its sources, with no whole-ride figure to test it against.
18. The fit tables use the bodies of US Army personnel. ANSUR II measured 6,068 soldiers aged 17 to 58 in 2010 to 2012; the way inseam varies at a given height should carry over to civilians, while the exact spread may not.
19. The 17-inch frame is Eunorau's photograph, held to its table on four dimensions; the 19-inch is that frame with Eunorau's printed differences (J 50 mm longer, reach 10 mm and stack 3 mm more), with the same post angle, cockpit and saddle. Its standover is not printed and is not given here.
20. The grip is read on the photograph at the adjustable stem's photographed setting, and the sit bones are placed in the saddle's rear-middle quarter; raising or lowering the stem moves the lean and the hand load, and the hand figure is a ceiling for a relaxed back.
21. The standover is read on the photograph 2 inches ahead of the saddle's nose, where you stand astride at a stop; where Eunorau's drawing drops its vertical G line, 222 mm ahead of the crank axle, the top tube reads 33.2 inches. Treat the saddle formula as a first setting: in 19 trained cyclists the inseam formulas put 55 to 65% inside the 25 to 35 degree knee range (Peveler et al., 2005).
22. The payload section quotes Eunorau's specification row, and the Mercer table names no statute. Expiry: re-verify if Eunorau changes a motor, the pack, the speed settings, the payload, the rider window, the geometry or the second pack's listing, if our price moves, or if any state's definition changes.

The source register

The tiers behind this review, and what each was used for: Eunorau's page, record, drawing, pack listing and policy, the statutes, the CPSC's lists, the published measurements under both models, and our own datasets.

Frequently asked questions

Is a dual-motor e-bike like the DEFENDER-S 2.0 worth it?

It is if your ground is loose or steep: with both 750 W hubs on the throttle the model holds 17.6 mph up a 12% grade with 180 lb aboard, and you still get about 53 miles at 12 mph on the flat. If your rides stay on pavement, the FAT-AWD 2.0 costs you $1,100 less (the family table).

How fast does the Eunorau DEFENDER-S 2.0 go?

It starts in Eunorau's Class 2 mode, assisted up to 20 mph, and Eunorau lists a maximum setting of "Up to 28 mph / approximately 45 km/h". On the flat the model carries a 180 lb rider to 20 mph on the throttle, and the law section screens your state at both speeds (the 28 mph setting).

How fast does a 1500W electric bike go?

On the DEFENDER-S 2.0, the setting caps the speed: its 1,500 W of combined rated power runs to 20 mph at startup, with a 28 mph maker setting. Where the 1,500 W shows is on a climb, where you hold 18.4 mph up an 8% grade at 180 lb (the climb table).

Are dual motor e-bikes legal?

It depends on how your state counts the motors: on October 2, 2026 the DEFENDER-S 2.0's printed figures sat inside 28 of 51 definitions counted per motor, and 3 counted as one 1,500 W system. Pennsylvania rates the whole "electric motor system", and the law section quotes the three definitions that take in a 1,500 W system.

Is a 1500W e-bike legal?

As an e-bike, only where the definition names no wattage: on October 2, 2026, the District of Columbia, Montana and Oregon at 20 mph. Forty-four states write a 750-watt line into the definition. Rhode Island caps the motor at two horsepower, about 1,492 W, which a 1,500 W system passes; read the law section for your state's words.

What is a dual motor electric bike?

A bike with a motor driving each wheel. On the DEFENDER-S 2.0 a 750 W hub sits in the front wheel and another in the rear, and a 48V 25A dual-motor controller runs the pair (the drive section). Eunorau sells it for "traction on loose, soft, or uneven surfaces".

Are dual motor e-bikes better?

For climbing and loose ground, yes: the second hub is why the DEFENDER-S 2.0 holds 14.0 mph up a 12% grade with the full 300 lb. On a paved commute you are moving 89.3 lb of bike, so match the bike to your ground (who it is for).

How far does the DEFENDER-S 2.0 go on a charge?

About 53 miles at 12 mph on both motors for a 180 lb rider on level pavement, 37 at 18 mph and 32 at 20, from the 816 Wh pack. Plan on 45 at 12 mph with 15% kept, and 85 with the 15 Ah second pack (the speed table).

What battery does the Eunorau DEFENDER-S 2.0 use?

A removable 48V 17Ah pack, 816 Wh, with a 50A BMS, charged in about 6 to 8 hours on a 54.6V 2A charger. Eunorau lists a 48V 15Ah second pack for the bike, 9.9 lb and $598.80 from us, and on the 17-inch frame its listing says to lock out the rear shock (the frame section).

What size DEFENDER-S 2.0 frame do I need?

If you are 5'7" with a 32.2-inch inseam, the median at that height, the 19-inch frame's 37.6 to 43.3 inch saddle range covers 99 of 100 riders your height, against 73 on the 17-inch. Riders up to about 5'6" ride the 17-inch, from 35.7 to 41.4 inches, and you can find your own row in the saddle tables.

How much does the DEFENDER-S 2.0 weigh?

Eunorau lists it at 89.3 lb (40.50 kg), and your 300 lb payload is on top of that. At that weight you lift it with a second person or roll it up a ramp, and the second pack adds 9.9 lb inside the payload (the frame section).

Do fat tire bikes need suspension?

A 26 × 4.0 tire at low pressure soaks up a lot on its own, and the DEFENDER-S 2.0 adds a 75 mm fork and a four-bar air-shock rear on top. If your rides are smooth gravel or pavement, a rigid-rear fat bike such as the FAT-AWD 2.0 may be all you need (the suspension section).

What is a torque sensor?

A sensor in the bottom bracket that reads how hard you press the pedals, so the motors match your effort. On the DEFENDER-S 2.0, in Eunorau's words, "Lighter pressure produces gentler support, while harder pedaling calls for more assistance" (the drive section).

Is the DEFENDER-S 2.0 good for hunting?

It is built for that kind of ground: two driven wheels, full suspension, fat tires, a Dry Grass Camo colorway and trailers among its listed accessories. Keep you and your gear inside 300 lb, plan your miles from the range tables, and check your state's hunting-land rules on motorized travel before you ride in.

What accessories fit the Eunorau DEFENDER-S?

Eunorau lists a rack and fender set ($178.80 here), the 48V 15Ah second battery ($598.80 here) and three trailers among the DEFENDER-S 2.0's compatible accessories, and we stock each one. The payload section links them, and the trailers carry what you would rather not strap to the bike.

What is the difference between the Defender and the DEFENDER-S 2.0?

The DEFENDER-S 2.0 drives both wheels with two 750 W hubs on 26 × 4.0 fat tires and full suspension; Eunorau's Defender uses one rear hub on 27.5 × 3.0 tires. If you have read about the first Defender S, the 2.0's figures differ too: 89.3 lb, 300 lb payload, 203 mm rotors (who it is for).

Are Eunorau bikes good?

You can check Eunorau part by part, because it names them: on the DEFENDER-S 2.0 an RST GUIDE fork, an AOS01 air shock, Shimano CUES gears, 203 mm hydraulic rotors, a 10-year frame warranty and a "UL CERTIFIED Yes" mark. Our Eunorau brand profile covers the whole range.

The bottom line

The Eunorau DEFENDER-S 2.0 is a $2,799 full-suspension fat-tire bike with a 750 W hub in each wheel, nine gears, 203 mm hydraulic brakes and an 816 Wh pack, rated to 300 lb, in a 17- or 19-inch frame: inside 28 of 51 jurisdictions' e-bike definitions counted per motor and 3 counted as one 1,500 W system, on October 2, 2026.

On both motors a 180 lb rider covers about 53 miles at 12 mph, 37 at 18 and 45 at 12 mph with the full 300 lb, and the pair holds 17.6 mph up a 12% grade. Buy it for loose ground, snow, trails and climbs; take the 17-inch to about 5'7" and the 19-inch above.

References

Every document behind the figures and rules on this page, numbered in the order the page first leans on it, with its publisher, title, the part cited and the date we read it.

1. Eunorau. DEFENDER-S 2.0 (DEFENDER S 2.0/Hunter X6) — product page and product record: highlights, specification rows, the Dimensions & Rider Fit table for both frames, the lettered geometry drawing, the feature copy, the product FAQ, the compatible accessories and the studio gallery. eunorau-ebike.com/products/defender-s; product record defender-s.json. Retrieved October 2, 2026; deposit copies archived.
2. Eunorau. FAT-AWD 2.0 product page and record: two 500 W hubs, the 95 mm fork, the 81.5 lb weight and the 375 lb payload. fat-awd-2. Retrieved September 26 and 30, 2026; deposit copies archived.
3. Eunorau. FAT-AWD 3.0 product page and record: the step-through, two 500 W hubs, the 79.4 lb weight and the 375 lb payload. fat-awd-3-0. Retrieved September 26 and 30, 2026; deposit copies archived.
4. Eunorau. EUNORAU Universal 48V15Ah Secondary Battery, product page and record: $499, 9.9 lb, "Down tube battery type", and its list of compatible bikes, "DEFENDER-S 17" (*Lock out rear shock to use)" and "DEFENDER-S 19"" among them. eunorau-48v15ah-second-battery. Retrieved October 2, 2026; deposit copies archived.
5. Eunorau. FLASH AWD 1.0 product page and record: two 52 V, 750 W hubs, the bench seat, the 80 mm fork, the 82–92 lb weight and the 440 lb payload. flash-awd-1-0. Retrieved September 26 and 30, 2026; deposit copies archived.
6. Eunorau. FAT-HS (Hunter X8) product page and record: the 17- and 19-inch frames, the rear shock, the 1,000 W mid-drive, the 79.4 lb weight and the 300 lb payload. fat-hs. Retrieved September 26, 2026; deposit copies archived.
7. Eunorau. Frame Size Suggestion: rider height by frame size, XS to XL. eunorau-ebike.com/pages/frame-size-suggestion. Retrieved September 26 and October 2, 2026, unchanged between the two; deposit copies archived.
8. The state legislatures of the 44 states that write a 750-watt line into their electric-bicycle definitions. Each state's electric-bicycle definition, at the section our 51-jurisdiction rule table cites, with its own boundary word for the motor. Read for the boundary-word census of September 24, 2026, with Connecticut's P.A. 26-24 § 26 applied from its effective date, October 1, 2026; re-screened October 2, 2026.
9. Pennsylvania General Assembly. 75 Pa.C.S. § 102, the definition of a "Pedalcycle with electric assist": "an electric motor system rated at not more than 750 watts". palegis.us. Read for the boundary-word census of September 24, 2026; deposit copy archived.
10. Council of the District of Columbia. D.C. Code § 50-2201.02(11A), the motorized-bicycle definition: the seat, wheel, pedal and 20 mph motor limbs. code.dccouncil.gov. Read for the census of September 24, 2026; deposit copy archived.
11. Montana Legislature. MCA § 61-8-102(7), the electrically assisted bicycle: a motor moving "a rider who weighs 170 pounds no faster than 20 miles an hour on a paved, level surface". mca.legmt.gov. All Title 61 sections read September 23, 2026; deposit archived.
12. Oregon Legislature. ORS 801.258, the three classes of electric assisted bicycle, as amended by 2024 c.12 § 1, which deleted the wattage limb. oregonlegislature.gov. Read for the census of September 24, 2026; deposit copy archived.
13. Rhode Island General Assembly. R.I. Gen. Laws § 31-1-3(g): "an electric motor rated not more than two (2) (S.A.E.) horsepower". webserver.rilegislature.gov. Read for the census of September 24, 2026; deposit copy archived.
14. Redtail eBikes editorial desk. The 51-jurisdiction rule table, its boundary-word census and dated changes, and the four DEFENDER-S 2.0 screens. Every US state and DC, each row carrying its statutory citation and each wattage read with the statute's own word; screened October 2, 2026 on the published throttle and Eunorau's 89.3 lb: at 750 W per motor and 20 mph (inside 29 by the rule table, 28 with Pennsylvania's system rating applied, outside 20, no definition in Alaska and Kentucky), at 1,500 W combined and 20 mph (inside 3, outside 46, no definition in 2), and at 28 mph on both readings (inside none). A word search of the 51 deposited definitions for multi-motor wording found it in Pennsylvania's alone. First-party datasets.
15. California Legislative Information. Cal. Veh. Code § 312.5, subsection (a): the definition's "an electric motor that does not exceed 750 watts of power". leginfo.legislature.ca.gov. Retrieved September 26, 2026; deposit copy archived.
16. Eunorau. EUNORAU EBIKES FAQ: battery life ("5-6 years"; "more than 80% of their original capacity after 500 charge cycles") and the 10-15% recharging and 70%-80% storage advice. eunorau-ebike.com/pages/faqs. Retrieved September 26 and October 2, 2026, unchanged between the two; deposit copies archived.
17. U.S. Consumer Product Safety Commission. SaferProducts recall database. saferproducts.gov/RestWebServices/Recall. Screened October 2, 2026 for "Eunorau" on the RecallTitle, RecallDescription and ProductName fields, each proved live by a control query; the full list of 10,027 recalls, June 8, 1973 to September 24, 2026, read for "Eunorau", "DEFENDER-S", "Defender" and "Hunter X6" on whole words after the model-name queries returned HTTP 503; and the 51 recalls whose titles carry one of eight electric-bicycle, e-bike or electric-scooter terms. Screens and the list archived.
18. U.S. Consumer Product Safety Commission. Product safety warning listing (complete CSV). cpsc.gov. Read October 2, 2026: 373 warnings, 2 naming the control brand, none naming Eunorau, the DEFENDER-S, the Defender or the Hunter X6; screen archived.
19. UL Standards & Engagement (standards body; context only). UL 2849 and UL 2271. Retrieved August 29, 2026.
20. Eunorau Bikes. 24-Month+ Limited Warranty: coverage periods, requirements, exclusions and the issuing entity. eunorau-ebike.com/pages/warranty. Retrieved September 26 and October 2, 2026, unchanged between the two; deposit copies archived.
21. Redtail eBikes. DEFENDER-S 2.0 store record (redtailebikes.com/products/eunorau-defender-s-2): the three colors and two frames, prices, orderability and the Shop Pay plan table; the 48V 15Ah second pack, the rack and fender set and the trailers; the FAT-AWD 2.0, FAT-AWD 3.0, FLASH AWD 1.0 and FAT-HS prices; and our shipping policy. Read October 2, 2026.
22. Affirm. Lending partners. affirm.com/lenders. The lenders behind Shop Pay's installment plans, named in Shopify's installment terms.
23. Bafang. Workbook OEM 2021, MOTORS table, RM G0H0 column: rated voltage, n0, nT, maximum torque and efficiency. bafang-e.com. Retrieved September 23, 2026; deposit copy archived.
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41. Redtail eBikes editorial desk. DEFENDER-S 2.0 range model. The computation set out in the range section of this review: Martin et al.'s power model with two of Bafang's RM G0H0 curves, each wound for Eunorau's 48 V and 750 W, capped at 85 N·m and together fitted to its 20 mph Class 2 start, splitting the torque equally, on a 30.01-inch 26 × 4.0 wheel and the median of ten fat tires, with a sensitivity run at 42.5 N·m a hub; Eunorau's 40 and 80 miles mapped to rides; run October 2, 2026. First-party computation; every input and its source in its inputs table.
42. Redtail eBikes editorial desk. DEFENDER-S 2.0 fit model, two frames. Eunorau's chain-side photograph of the 17-inch frame, scaled by its 1,306 mm wheelbase and held to four of its table's dimensions within 3.5%; the seat post's axis fitted on 22 rows; Eunorau's J seat-height range placed along it for each frame; the 19-inch from Eunorau's printed differences; every ANSUR II body through the saddle formula at Eunorau's 170 mm crank; October 2, 2026. First-party computation; every input and its source in its inputs table.