Eunorau DEFENDER Review: Full Suspension, 55 Miles

66 lb · 27.5 × 3.0 tires · 500 W rear hub, 60 N·m · 100 mm fork, 165 mm rear shock · Shimano 7-speed · 720 Wh · 20 mph Class 2 locked, 28 mph off-road setting · 300 lb payload · 17" or 19" frame · $1,599 · verified October 2, 2026

Quick Answer: The Eunorau DEFENDER is a $1,599 full-suspension e-bike: one 500 W rear hub, a 100 mm fork and a 165 mm rear shock, seven Shimano gears and 180 mm hydraulic brakes on 27.5 × 3.0 tires, at 66 lb. On the throttle a 180 lb rider covers about 55 miles at 12 mph over level pavement.

It is the one-motor bike in Eunorau's DEFENDER line: the DEFENDER-S 2.0 puts a hub in each wheel and weighs 89.3 lb (our DEFENDER-S 2.0 review). Take the 17-inch frame below about 5'5" and the 19-inch from about 5'5" to 5'9" (the fit section). Its printed 500 W, throttle and 20 mph sit inside 48 of 51 jurisdictions' e-bike definitions on October 2, 2026 (the law section).

What's on this page

Twenty-seven sections: who the DEFENDER suits, its motor, suspension, parts and frames, Eunorau's other bikes with a rear shock, the range and payload, your fit, the law at 20 and at 28 mph, ownership, and the verdict.

• Who the DEFENDER is for
• How we verified this Eunorau DEFENDER review
• Eunorau DEFENDER specifications
• One 500 W rear hub and a thumb throttle
• A 100 mm fork and a 165 mm rear shock
• Seven gears, 180 mm brakes and the display
• Two frame sizes and the second battery
• DEFENDER or another Eunorau with a rear shock
• How far the DEFENDER goes on one charge
• What the 300 lb payload covers
• Will the DEFENDER fit you?
• The Mercer fit test
• What the law calls it: 500 W, 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 is for

The Army Green as Eunorau photographed it, set on a light studio backdrop made for this card. Eunorau prints the $1,599 and the 500 W rear hub; the 55 miles come from the range section.

The DEFENDER suits you if your rides mix pavement with dirt: a gravel road to the trailhead, a rooty path through the woods, a washboard farm lane, or a city street full of potholes. Eunorau pitches it the same way, "Full suspension to smooth out every trail" and "Wherever the pavement ends, your ride begins" (Eunorau's DEFENDER page).

The Army Green from the drive side, in Eunorau's studio photograph: an olive frame with the shock tucked under the top tube and the motor in the rear wheel.

At 66 lb by Eunorau's weight row, the DEFENDER is the second-lightest bike in the family table and the lowest-priced. Two people lift it onto a hitch rack, and on a trail that runs long the motor brings you home.

Eunorau's own copy places it at "light off-road adventures", and the parts it lists match that ground: a 100 mm fork, a 165 mm rear shock, 27.5 × 3.0 tires and a 44-tooth chainring behind an aluminum bash guard (its feature and specification rows).

Want two driven wheels for steep, loose ground? Our DEFENDER-S 2.0 review covers the dual-hub version at $2,379. Want a mid-drive with eleven gears? Our SPECTER-ST 2.0 review covers a full-suspension step-through on Bafang's M620.

How we verified this Eunorau DEFENDER review

Every specification is Eunorau's, read from the DEFENDER page and its product record on October 2, 2026, and every figure that needs arithmetic is recomputed here. Where two of Eunorau's own sources give different figures, the conflicts table shows each one.

The range and fit sections close with their formula and every input (range, fit). The law section screens all 51 jurisdictions at both printed speeds, and the Limitations date each read. We sell the DEFENDER, and the honest ledger sends each rider it suits less well to another of our bikes. Milad Ghobadibeygvand, BScN (Western University, 2014), wrote it; send corrections to corrections@redtailebikes.com.

Eunorau DEFENDER specifications

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

The geometry table on the DEFENDER page, both frames:

Read from the DEFENDER page on October 2, 2026; the inch figures are Eunorau's. Eunorau's drawing places its H and B lines along the top tube (the fit section).

One 500 W rear hub and a thumb throttle

A 48 V, 500 W hub motor turns the rear wheel with up to 60 N·m, run by a 48 V, 20 A controller (Eunorau's specification). A thumb throttle moves the bike with no pedaling, and five pedal-assist levels add power while you pedal.

The rear wheel from the left, cropped from Eunorau's photograph of the Army Green: the hub motor fills the center of the wheel behind its rotor.

On the throttle alone, the modeled hub holds 15.3 mph up a 4% grade and 10.4 mph up an 8% grade with 180 lb aboard (the climb table). On a long, steep climb your legs share the work: in a low gear the hub and your pedaling together carry you where the throttle alone slows.

The brake levers carry a "motor cutoff switch" (Eunorau's brake-lever row), so pulling either lever stops the drive.

A 100 mm fork and a 165 mm rear shock

Both wheels move: a ZOOM fork with 100 mm of travel up front and an EXA KS/A5 shock, 165 mm, working the rear (Eunorau's specification). Eunorau's feature copy describes the fork's "100mm of travel, compression adjustment" and calls the rear its "unmatched air rear suspension".

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

Set the fork's compression for your ground before a trail ride: firmer for a smooth climb on a graded road, softer for roots and broken pavement. The adjustment is printed in Eunorau's front-suspension copy.

The front end, cropped from Eunorau's front three-quarter photograph: the fork, the front rotor and the CHAOYANG tire.

The 27.5 × 3.0 CHAOYANG tires add their own cushion, and Eunorau names them in its tire row.

Seven gears, 180 mm brakes and the display

You shift seven speeds with a SHIMANO ASLM315 7RC-7S shifter, over a 14–28T freewheel driven by a 44-tooth aluminum chainring on 170 mm forged cranks (Eunorau's specification). Eunorau's copy: "Conquer hills with larger cogs, speed up with smaller cogs".

Hydraulic discs stop both wheels on 180 mm rotors, and Eunorau calls them "sensitive yet powerful" in its feature copy. A side aluminum bash guard protects the chainring teeth and keeps the chain in place, in Eunorau's words.

The rest, as Eunorau lists it:

• The display: a BC182 screen with EUNORAU APP support; the feature copy says it "integrates with the EUNORAU GO app".
• The assist: five pedal-assist levels plus zero, and a thumb throttle.
• The lights: a 40 LUX LED headlight, switched from the handlebar, and a taillight.
• The wheels: 27.5-inch black alloy rims under CHAOYANG 27.5 × 3.0 tires.
• The rest: a "Comfortable Saddle", nylon pedals, and a tool, which the specification lists as "Included".

Two frame sizes and the second battery

The DEFENDER comes in a 17-inch and a 19-inch frame at the same $1,599: Army Green in both, Safari in the 19-inch. Eunorau's table separates them by 51 mm of seat tube and 25 mm of top tube; the wheelbase grows from 1,306 to 1,316 mm, and the chain stay, bracket height and head tube stay the same.

The Safari, photographed by Eunorau from the drive side: a sand finish with the DEFENDER name on the top tube.

At 66 lb and 80.4 inches long on the 17-inch frame (Eunorau's row I and weight row), it needs a hitch rack rated for at least 66 lb per bike. Check the rack's tray width against the 3.0-inch tires before the first trip.

A second pack doubles the energy, to 1,440 Wh. Eunorau's DEFENDER page lists the "EUNORAU Universal 48V15Ah Secondary Battery" among its compatible accessories, and that pack's listing names the "Defender" among its bikes, with Samsung cells and a weight of 9.9 lb. Ours is $598.80.

The 15 Ah pack's listing names the "Defender" without the "(*Lock out rear shock to use)" note it prints beside three other bikes, the DEFENDER-S 17" among them. The DEFENDER page's own note covers the larger pack: "The second 17ah battery is not compatible with 17" DEFENDER; To utilize the 17Ah second battery on the 19" DEFENDER, it's necessary to lock out the rear shock" (Eunorau's note).

The Army Green from the front three-quarter, in Eunorau's studio photograph: the fork and headlight, the pack in the down tube and the shock beneath the top tube.

DEFENDER or another Eunorau with a rear shock

Here the DEFENDER sits beside four other Eunorau bikes we sell with a fork and a rear shock, and it is the one in this table with a single hub motor, at $1,599. The other four run two hubs or a mid-drive.

Each row comes from that model's page at Eunorau (DEFENDER-S 2.0, SPECTER-ST 2.0, FAT-HS, URUS 2.0), read September 26 and October 2, 2026; Eunorau prints the FAT-HS at 77.1 lb in its specification and 79.4 lb in its geometry table. Our prices were read October 2, 2026.

Pick the DEFENDER for full suspension at the lowest price and the second-lowest weight in this table.

Pick the DEFENDER-S 2.0 for a motor in each wheel on loose, steep ground, the SPECTER-ST 2.0 to step through onto a mid-drive, the FAT-HS for a mid-drive on 4.0 tires, and the URUS 2.0 for the lowest weight here and RockShox suspension. Our Eunorau collection holds all five, and the rest of the range.

The Safari from behind, photographed by Eunorau: the rear hub motor and rotor, the taillight under the saddle, and the side stand down.

How far the DEFENDER goes on one charge

A 180 lb rider on the throttle covers about 55 miles at a steady 12 mph over level pavement from the DEFENDER's 720 Wh pack, about 35 at 18 mph and about 30 at the 20 mph Class 2 limit.

Keep 15% in the pack, the top of the 10 to 15% Eunorau's FAQ says to recharge at, and those become 47, 30 and 26 miles to plan on. Fit the optional 15 Ah second pack, 1,440 Wh between the two, and a 12 mph day plans at 94 miles.

All of it comes from one saved model of this bike, set to Eunorau's printed figures: a 48 V, 500 W rear hub with 60 N·m, the 48V15Ah pack, 66 lb, 27.5 × 3.0 tires and the 20 mph locked setting. The formula lists every input and the physics behind it.

Read your own ride in three passes:

1. Find your pace in the speed table. 12 mph is an unhurried gravel or bike-path pace; 18 mph is a brisk road-shoulder ride.
2. Adjust for what you weigh and where you ride, using the weight rows (100 lb to the 300 lb rating) and the hill tables (2% to 12%).
3. Plan from the "15% kept" column, because Eunorau's battery advice is to recharge with 10 to 15% left.

How far does it go at my speed?

Speed is the setting you control that moves range most: 72 miles at 8 mph falls to 30 at 20 mph on the same charge. Air drag rises with the square of your speed and the power to beat it with the cube (Martin et al., 1998), so holding 20 mph where 15 would do costs you 31% of the miles.

On the throttle with a 180 lb rider, level pavement, still air at 77 °F. "15% kept" leaves the top of Eunorau's recharge window in the pack; the last column adds the optional 15 Ah second pack for 1,440 Wh.

Pedal and the same pack goes much further. The hub turns the rear wheel whether your legs help or not, so every watt you add is a watt the cells keep:

The 720 Wh pack and a 180 lb rider on level ground. Easy pedaling means 75 W at the cranks, steady means 150 W; "legs alone" means 150 W of yours holds that pace with the motor drawing nothing.

To hold 12 mph the rear wheel needs 120.4 W (Martin et al., 1998). Put in 75 W and the hub makes up the difference on 5.5 Wh a mile, about 130 miles a charge; put in 150 W and you carry the pace with the motor idle.

Without the motor at all, the same road-power equation moves you and the 66 lb bike at about 9 mph on 75 W and about 13 mph on 150 W.

Which gear saves battery?

The DEFENDER's hub sits in the rear wheel, so the seven gears change your cadence and leave the motor's load alone. The battery saving comes from your effort: at 12 mph on the flat it lowers the draw from 13.0 Wh a mile to 5.5, and at 12 mph up a 4% grade from 43.6 to 32.9.

Watt-hours drawn from the 720 Wh pack per mile, a 180 lb rider, still air. At 150 W your legs carry the flat at 12 mph and the hub draws nothing; "—" marks a pace the hub cannot hold on the throttle alone.

Shift down before the grade starts, while the chain is under light load, so your legs keep turning as the bike slows. Eunorau lists a 44-tooth chainring, a 14–28T seven-speed freewheel and a Shimano 7-speed shifter (its drivetrain rows).

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

On the throttle at 10 mph, each 1,000 feet of climbing costs about 149 Wh on a 4% grade and about 183 Wh on an 8% grade, on top of what the same distance costs flat. Raising a 180 lb rider and the 66 lb bike 1,000 feet takes about 93 Wh at the wheel; the motor and the pack turn the rest into heat.

The 720 Wh pack and a 180 lb rider holding 10 mph up each grade in still air.

The steadiest speed each grade allows on the throttle:

On the throttle in still air: the 66 lb bike plus the load in each column, the hub held to Eunorau's 60 N·m. Each cell is the fastest steady speed the modeled hub holds on that grade.

Up a 12% grade the hub alone holds 7.6 mph with 180 lb aboard, and at 260 lb a 12% grade needs your legs as well. That is a single 500 W rear hub's limit on steep trail; pedal in a low gear and the climb stays smooth. For two driven wheels on steep ground, our DEFENDER-S 2.0 review sets out the dual-hub version.

Does my weight change the range?

Yes, and most on climbs: on the flat at 12 mph, 180 lb of rider and gear goes 55 miles and the full 300 lb goes 44. Up an 8% grade at 10 mph a 100 lb load covers 14 miles; from 220 lb up, the modeled hub cannot hold 10 mph on that grade without your legs.

Rider and gear on the 66 lb bike, the 720 Wh pack, still air. "Past the model's motor" means the hub alone cannot hold that pace at that load.

Does cold weather drain the battery?

Yes: the 55-mile ride at 12 mph shortens to about 43 miles at 32 °F and about 39 at 14 °F. At freezing a lithium cell returns about 89% of the energy it gives at 77 °F, the air is about 9% denser, and tires roll about 18% harder (Rothhämel, 2023).

12 mph on the throttle, 180 lb aboard, level pavement, the 720 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 the bracket spans the other published cell data (Limitations).

Store and charge the pack indoors through a cold spell, and fit it just before you ride, so the cells start warm.

Do the tires cut range?

Less than your speed does: across the ten fat-bike tires Bicycle Rolling Resistance measured on its drum, the 12 mph ride runs from 50 to 67 miles, with 55 at the median. Eunorau names the tire "CHAOYANG Tires 27.5 x 3.0" without a tread or casing, so the model uses the median of the ten wide tires on the lab's fat-bike drum, the slowest and fastest of them as the bracket.

180 lb aboard on the throttle over level pavement, the 720 Wh pack. The lab rolled each tire at 12 psi under 42.5 kg at 29 km/h; the first column turns its watts into a rolling-resistance coefficient.

Eunorau's 80 miles, as a ride

Eunorau prints "Up to 80 miles (with dual batteries)" (its specification). In this model a 180 lb rider on level ground in still air reaches 80 miles on two 15 Ah packs at a steady 16.4 mph on the throttle, or at 19.7 mph pedaling easily alongside.

On the single 15 Ah pack the bike ships with, the same rider covers about 44 miles at 15 mph on the throttle. Eunorau's highlights carry the same figure as "Up to 80 Miles (Dual Battery)", so read it as the two-pack number it is.

How the range tables are computed

Every row starts from the power the wheels need at one steady speed, from the road-power equation that Martin and colleagues validated against riders on real roads in 1998:

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

Here v is speed; m is rider, gear and bike together; g is gravity; θ is the grade's angle; Crr is rolling resistance, where 0.0105 means a drag of 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 rear wheel back to the cells, four steps:

1. Your pedaling reaches the rear wheel through the chain at 97.7% (Martin et al., 1998); the hub supplies whatever is left.
2. The hub follows the curve of a hub motor with published figures, Bafang's RM G0H0: 510 rpm unloaded, 426 rpm at its rated point, "≥ 80" percent efficient, here wound for 48 V and 500 W. Its unloaded speed is fitted at 22.7 mph so that it carries a 180 lb rider on the throttle to Eunorau's 20 mph and no faster, and its torque is capped at Eunorau's 60 N·m.
3. The pack turns some energy into 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 over the speed, and miles are the 720 Wh, less any cold loss, over the watt-hours per mile.

A worked ride, wheel to cells: 180 lb aboard on the throttle at 12 mph over level pavement. The tires take 61.9 W and the air 58.5 W, so the rear wheel needs 120.4 W, and a 28.99-inch wheel turns 139.1 times a minute.

The modeled hub (1.742 N·m per amp, 0.607 Ω, and 0.55 A unloaded, from Bafang's published figures wound for 48 V and 500 W) turns out 8.3 N·m on 5.3 A, about 80% efficient at that load.

The hub draws 151.3 W, and with the pack's own losses the cells give up 156.2 W, 13.0 Wh a mile. Carried to two decimals it is 13.01, and 720 ÷ 13.01 gives 55.3 miles, or 47.0 when 15% stays in the pack.

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 no-load check in the model's own selftest.

What the 300 lb payload covers

Eunorau rates the DEFENDER for a "Total Payload Capacity" of "300 lbs / 136kg" (its specification). You and everything you carry on the bike count toward the 300 lb; the bike's own 66 lb sits outside it.

Take a 210 lb rider with a 40 lb pack and the 9.9 lb second battery, about 260 lb, inside the rating with room to spare. At 12 mph on the throttle the weight table gives that load about 47 miles per pack (the weight table), and the hub holds 13.0 mph up a 4% grade (the climb table).

The Safari from the front, in Eunorau's studio photograph: the fork and front rotor, the headlight and the sand frame.

Weigh what you will carry before the first trip, and keep you, your pack and anything bolted on inside Eunorau's 300 lb. For loads that ride behind the bike, Eunorau lists three trailers among the DEFENDER's compatible accessories; we stock the hunting trailer at $376.80, the two-wheel hunting trailer at $336.00 and the one-wheel cargo trailer at $336.00.

Will the DEFENDER fit you?

Pick the frame by your height: below about 5'5" the 17-inch frame, where 89 of 100 riders at 5'3" clear its top tube. From about 5'5" to 5'9" the 19-inch fits better: its saddle range reaches the fit formula's height for 99 of 100 riders at 5'5" and 61 of 100 at 5'9".

Above that the 19-inch saddle sits lower than the formula asks, so taller riders set it at the top and read the shortfall row for their height. On the 19-inch frame you lean about 27 to 28 degrees toward the grips across those rows, and with a relaxed back your hands carry about a fifth of your weight.

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

Your frame in three steps:

1. Measure your inseam barefoot. Back against a wall, pull a hardcover book up snugly between your legs where a saddle would sit, and measure from the floor to its top edge.
2. Find your height in both saddle tables and in the standover table, and check that your inseam sits inside that row's range; a longer inseam behaves like the row above.
3. Choose the frame you can stand over that also reaches your saddle height, then set the saddle on arrival with the knee and heel checks near the end of this section.

Eunorau prints one rider window for the bike, "Recommended Rider Heights: 5'3" ~ 6'4"", on the DEFENDER page, and no window for each frame.

Eunorau's frame-size guide places a 17-inch frame where its 5'2"–5'6" row meets its 5'6"–5'10" row, and a 19-inch where 5'6"–5'10" meets 5'10"–6'1". The tables below follow your inseam, and from about 5'10" up they part from the window's top.

How high should the saddle go?

Set the saddle 109% of your inseam above the pedal axle; on the 17-inch frame Eunorau's printed range covers that for 98 of 100 riders at 5'2", 87 at 5'4" and 46 at 5'6". Published practice spans 106% to 110.4% of inseam (Ferrer-Roca et al., 2012), and 109% is the figure Peveler and colleagues measured against knee angle in trained cyclists.

Eunorau prints one saddle range, "height to ground 35.0"-40.9"", without naming a frame. Its photograph of the 19-inch frame shows the saddle about 41.5 inches off the ground, above that range's top, so this review reads 35.0 to 40.9 inches as the 17-inch frame's.

The 19-inch frame's seat tube is 51 mm longer (Eunorau's row A); along the seat post's 74.5-degree lean that raises its range about 1.9 inches, to 36.9 to 42.8.

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 printed 35.0 to 40.9 inches, at 109% and at 106%. ANSUR II bodies, women and men pooled; the 17-inch frame uses Eunorau's 170 mm cranks.

The same rows on the 19-inch frame's 36.9 to 42.8 inches: Eunorau's printed range raised by the 19-inch frame's longer seat tube.

At 5'10" the 19-inch saddle stops a median of about 0.8 inches short for the riders whose formula height it misses, at 6'0" about 1.7 inches and at 6'2" about 2.7. Many riders at those heights ride a little lower than 109%: at the 106% setting the 19-inch covers 74 of 100 at 5'10" and 29 at 6'0".

If you are 6'0" or taller, read the 106% column for your row and set the final height with the heel check below.

Can I put a foot down at a stop?

On the 19-inch frame, straddling the bike at a stop, 30 of 100 riders at 5'4" clear the top tube barefoot, 75 at 5'6" and 97 at 5'8". Eunorau prints no standover, so the top tube's upper edge is read on its photograph of the 19-inch frame, 2 inches ahead of the saddle's nose, at 31.0 inches.

How many riders of 100 at each height stand over the 19-inch frame's top tube, 31.0 inches up, in bare feet. Shoes add a little; if you do not clear it, you tip the bike to one side to put a foot down.

The 17-inch frame's top tube sits lower. Eunorau's table gives its H line, which it draws under the top tube near the seat tube, 416 mm on the 17 and 465 mm on the 19, 49 mm apart; read across, that puts the 17-inch top tube about 29.1 inches up at the same point. On that derived figure, 64 of 100 riders at 5'2" and 89 of 100 at 5'3" clear it barefoot.

Eunorau's own lettered drawing, from its DEFENDER gallery; the figure for each letter is in the geometry table. The H line stands under the top tube near the seat tube and B runs along the top tube, so neither is the stack or reach a bike shop would measure.

Will I feel cramped, or stretched out?

Expect an active, mountain-bike lean: on the 19-inch frame the median rider tips 26 degrees from vertical at 5'0" and 28 at 5'8" to reach the grips. On Eunorau's photograph the grips sit 21.5 to 22.9 inches ahead of the crank axle and 29.9 to 31.3 inches above it; the 17-inch frame's reach, by Eunorau's B, is 10 mm shorter.

Lean from vertical for the median rider on the 19-inch frame as photographed: the smallest trunk angle at which a straight arm meets the grips from where the sit bones rest, across the saddle's sit zone and the grip's extent.

On the 17-inch frame the saddle sits lower for the same rider, so the lean eases: the model puts the median rider at 25 to 26 degrees from 5'0" to 5'8". The stem Eunorau lists, "EUNORAU TDS-D507G-8FOV", is the part to look at with us if you want the grips higher.

How much weight goes on my hands?

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

How much of your body weight rests on the grips, back relaxed, on the 19-inch frame, worked from each body's segment weights (Clauser et al., 1969); the span runs across the sit zone and the grip's length, and the weight column is the survey's median at each height.

A trunk you hold up yourself takes some of that load off, so treat each row as the upper figure. On the 17-inch frame the model gives 19% across 5'0" to 5'10". Padded gloves help on long days: 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?

Your target is a knee bent 25 to 35 degrees when the pedal sits at the bottom of its stroke (Peveler et al., 2007). The quickest route there is the heel check: put your heel on the low pedal and raise the saddle until that leg just straightens. In 19 trained cyclists it put 70% inside the knee range, more than either inseam formula did (Peveler et al., 2005).

With the bike held upright, loosen the seat clamp, set the height by the heel check, and tighten the clamp firmly before the first ride.

How we computed fit

Three rules build every fit row: the saddle sits 1.09 inseams above the pedal axle, the lean is the smallest trunk angle at which a straight arm meets the grip, and the hand load is the share of upper-body weight that lean places on the bar.

Take a worked case: a rider of 5'8" with a 32.6-inch inseam, the median the survey records at that height. Measured from the pedal axle, that rider's saddle sits 35.6 inches up; take off the 170 mm crank and it is 28.9 from the crank axle (LeMond's 88.3% of inseam gives 28.8).

Up this frame's 74.5-degree post from a crank axle 14.0 inches off the ground, that is a saddle top 42.0 inches up: past the 17-inch frame's 40.9-inch top, and inside the 19-inch frame's 42.8.

The photograph is Eunorau's Army Green 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 any point was read, its scale was checked against Eunorau's table for the 19-inch frame.

The scale is set by the 19-inch column's 51.8-inch wheelbase, measured axle center to axle center. The total length, chain stay and bracket height land within 1.8%, and the seat tube reads 19.9 inches to the top of its clamp ring against the 19 column's 19 and the 17 column's 17. Eunorau's stack and reach lines are drawn at other points than a shop's, so they are not compared here.

Run across all 6,068 bodies, LeMond's route with a 170 mm crank comes to 109.0% of inseam from the pedal, close to the 109.2 ± 0.9% measured in trained cyclists (Peveler et al., 2005).

The Mercer fit test

The Mercers are the family every one of our reviews is read against, and each verdict below rests on a figure Eunorau prints or on the fit model's row for that height.

What the verdicts read: a 17-inch saddle range of 35.0 to 40.9 inches off the ground, 36.9 to 42.8 on the 19-inch, a 19-inch top tube 31.0 inches up, the 300 lb payload, the 66 lb weight, and the law set out in the next section.

For the Mercers the DEFENDER is a 19-inch bike: Maya, Dana and Frank ride it, Ruth checks her inseam against 31 inches, and Cole and Jack sit where its saddle falls short of most riders their height.

What the law calls it: 500 W, a throttle and 20 mph

On October 2, 2026, the DEFENDER's printed 500 W, its throttle and its 20 mph locked speed sat inside the e-bike definitions of 48 of 51 jurisdictions. Eunorau's highlights call it "Class 2", and its specification gives the speed as "20 MPH (32 KM/H) under speed limited/locked" (Eunorau's page).

The 500 W motor sits under the wattage limit of every one of those definitions that sets one. California's, for one, asks for "an electric motor that does not exceed 750 watts of power" (Cal. Veh. Code § 312.5(a)).

Rhode Island writes its limit in horsepower, "two (2) (S.A.E.) horsepower" (R.I. Gen. Laws § 31-1-3(g)), and the motor sits under that as well.

Pennsylvania adds a weight limb, a vehicle "weighing not more than 100 pounds" (75 Pa.C.S. § 102), and the DEFENDER's 66 lb meets it.

New Jersey is the one state whose definition leaves a throttle bike out. Under P.L.2025, c.285, its low-speed electric bicycle assists only while you pedal, and any throttle makes the bike a "motorized bicycle", which needs registration, a license and insurance (our New Jersey guide). Alaska and Kentucky write no e-bike definition at all.

Where a bike falls outside a state's definition, that state's code treats it as another kind of vehicle, and each state's statute says which. Our state guide links every state's own page.

The 28 mph setting

Eunorau's highlights call the DEFENDER "Class 2 Speed limited Unlockable", and its specification carries a note: "Riders can UNLOCK the speed limit on the display for off-road use to reach 28 miles per hour. Eunorau will not be held liable for riders that ride illegally configured bikes on-road" (Eunorau's note).

At 28 mph with a throttle, the DEFENDER sits inside none of the 51 definitions. Across our 51-jurisdiction rule table, each definition that permits a throttle cuts it off at 20 mph. Oregon's Class 2, for example, 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, keep the bike at its 20 mph setting. Every 20 mph figure on this page, the range tables included, is at the setting Eunorau's specification calls "speed limited/locked".

Charging and battery care

Eunorau ships a "US standard 2.0 A smart charger" (its charger row); 15 Ah at 2 A works out to about 7.5 hours from empty, by our arithmetic. A typical ride needs much less: 20 miles at 12 mph on the throttle draws about 260 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 ride for more than two weeks "in a cool, dry place with a 70%-80% charge remaining". It gives its batteries a typical life of "5-6 years" and "more than 80% of their original capacity after 500 charge cycles".

Where Eunorau prints a figure two ways

Eunorau describes the DEFENDER on its product page, in its product record, on a lettered geometry drawing and in the second pack's listing. Where two of them read differently, 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 specification rows matched the September 26 read row for row.

Recall and warning record

No federal recall names Eunorau or the DEFENDER e-bike. On October 2, 2026 the CPSC's recall database returned no recall for "Eunorau" in its title, description and product name fields, each field shown working by a control query.

That morning the model-name queries answered with a server error, so the full list of 10,027 recalls, June 8, 1973 to September 24, 2026, was read word by word. "Defender" appears in 8 of them: Can-Am Defender side-by-side vehicles, a doorknob, pool covers, football chin straps and an insect-trap part. None is a bicycle.

The same day, all 373 rows of the CPSC's product safety warning listing were read: two named the control brand, and none named Eunorau or the DEFENDER.

Is it UL certified?

Eunorau's DEFENDER page shows "UL CERTIFIED Yes" in its highlights. A mark like that rests on one of two standards: UL 2849 for an e-bike's whole electrical system, or UL 2271 for the battery pack alone. If your building, landlord or insurer asks for the certificate, tell us with your order and we will request it from Eunorau.

Warranty, and who handles a claim

Eunorau's warranty policy, read October 2, 2026, gives each part its own term:

The policy comes from "Eunorau Bikes, a Nevada corporation" and covers manufacturing defects in bikes bought in the US from August 1, 2023 (the policy). To claim, you need 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 to be the original purchaser.

For a bike bought before that date, the policy says it "is still subject to the original limited warranty", the 5-year frame and 12-month component terms Eunorau keeps on its Warranty Policy page; a DEFENDER ordered today falls under the first.

Order the DEFENDER from us and the claim is ours to run. Send a photo and a line on what failed, and we work with Eunorau until the part arrives at your door. Our Eunorau brand profile sets these terms out across the range.

Buying it from us

The value case in numbers. On October 2, 2026, our listing divided the $1,599 into 12 monthly payments of $144.32, 6 of $278.28 or 3 of $546.38, all 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.

Weighing the DEFENDER against the DEFENDER-S 2.0 or a mid-drive? Email your state, what you carry and the ground you ride to support@redtailebikes.com, and we will tell you which of them fits the job.

The honest ledger

Green flags

• Full suspension at 66 lb: a 100 mm fork and a 165 mm rear shock, the second-lightest bike in the family table at the lowest price.
• A 720 Wh pack, with a 15 Ah second pack that both frames take: about 55 miles at 12 mph on one pack for a 180 lb rider, and 94 planned on two (the range tables).
• A 500 W rear hub with 60 N·m: 12.5 mph up a 6% grade with 180 lb aboard on the throttle alone (the climb table).
• 180 mm hydraulic rotors at both ends, each lever cutting the motor (the parts section).
• Two frames at one price, the 17-inch below about 5'5" and the 19-inch from 5'5" to 5'9" in the fit tables (the fit section).
• Inside 48 of 51 e-bike definitions at its printed figures on October 2, 2026 (the law section).
• $1,599 on October 2, 2026, the price Eunorau charges itself, for either color and frame (buying from us).

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

• Your rides climb steep, loose ground with a heavy load: on the throttle alone the hub stops holding a 12% grade from 260 lb, so take the DEFENDER-S 2.0, a hub in each wheel (our DEFENDER-S 2.0 review).
• You are under about 5'2" and want a low frame to stand over: the FLASH LITE ST has a 17.5 in standover and a rider window from 4'8" (our FLASH LITE ST review).
• You are 6'0" or taller: the 19-inch saddle reaches 8 of 100 riders at 109%, so read the saddle tables and send us your inseam before ordering.
• You and your gear total more than 300 lb: the FAT-AWD 2.0 carries 375 lb on two 500 W hubs (our FAT-AWD 2.0 review).
• You live in New Jersey: any throttle bike there is a motorized bicycle with registration, a license and insurance, so read our New Jersey guide before you order.

Who should buy it

Buy the DEFENDER if you want full suspension for gravel, dirt paths, potholed streets and light trails at 66 lb, seven gears, 180 mm hydraulic brakes, room for 300 lb and a second pack, inside 48 of 51 e-bike definitions, for $1,599.

Choose the DEFENDER-S 2.0 instead for a motor in each wheel on steep, loose ground, the SPECTER-ST 2.0 to step through onto a mid-drive, and the FAT-AWD 2.0 for a load past 300 lb.

Hold off if you ride in New Jersey and do not want to insure your e-bike: a throttle bike there needs insurance on top of the registration and license every e-bike there now needs (our New Jersey guide).

Before you buy: the checklist

Eight checks before you buy: the first four settle the bike and the frame, the last four cover the order and the first week.

• ☐ Read your state's e-bike definition for one thing: whether it allows a throttle at 20 mph; start at our state guide.
• ☐ Measure your barefoot inseam and find your row in both saddle tables and the standover table: 17-inch below about 5'5", 19-inch from about 5'5".
• ☐ Add up your weight, your gear and any second pack and compare it with the 300 lb; the bike's own 66 lb sits outside that figure.
• ☐ Check your hitch rack's per-bike limit against 66 lb and its trays against 3.0-inch tires.
• ☐ Work out your longest ride at 12 mph on the throttle: one pack plans 47 miles for a 180 lb rider on the flat, two plan 94.
• ☐ If you want a second pack, order the 15 Ah; the 17 Ah fits only the 19-inch frame, with the rear shock locked out.
• ☐ Charge the pack fully before the first ride: about 7.5 hours from empty on the 2 A charger, by our arithmetic.
• ☐ Inspect the box before the carrier leaves, and send us photos of any damage within 48 hours.

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 and table, the second pack's listing and its FAQs, recomputed wherever arithmetic enters. The range and fit models, the two 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 motor count in the title, the speed, the saddle height's frame, the geometry letters, the rear shock, the range wording and the second pack more than one way (the conflicts table); the review uses the figure named there.
4. The screens set the printed 500 W, the throttle and Eunorau's 66 lb beside each definition at 20 mph and at 28 mph, as our rule table and the statutes stood on October 2, 2026. They read the motor, speed, throttle and weight limbs, leave age, helmet and trail rules to each state, and are not legal advice.
5. Connecticut's definition changed on October 1, 2026, from "fewer than" to "not more than" 750 watts (P.A. 26-24 § 26); the screens read the new wording, and the 500 W motor sits under both.
6. New Jersey's P.L.2025, c.285 took effect on January 19, 2026, and the screen reads its low-speed electric bicycle as pedal-assist only; our New Jersey guide sets out the fee waiver and the dates.
7. 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. The warning listing's 373 rows were read the same day.
8. Our price, orderability and Shop Pay terms come from our own listing, read October 2, 2026; the payments are its plan table for $1,599 at 15% APR.
9. The motor model rests on a comparable hub's published curve, Bafang's RM G0H0, wound for 48 V and 500 W, with the unloaded speed fitted so the hub carries a 180 lb rider to Eunorau's 20 mph and no faster. Eunorau does not name the hub or say whether it is geared.
10. The model caps the hub at Eunorau's 60 N·m and does not model the 48 V, 20 A controller's current limit; if the controller caps current below what the hub draws on a steep climb, the climb speeds run lower.
11. No drum or road figure for the CHAOYANG 27.5 × 3.0 tire was found, so the model uses the median of ten wide tires on Bicycle Rolling Resistance's fat-bike drum, bracketed by the slowest and fastest of the ten.
12. The model's wheel is the nominal 27.5 × 3.0 diameter, 28.99 inches, and its drag area the upright cruiser figure of 37 everyday riders; the photograph's tires measure 28.5 and 28.6 inches.
13. 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 Samsung cells in the second pack's listing.
14. The two-pack column uses the 15 Ah pack and leaves out its 9.9 lb; Eunorau's "Up to 80 miles (with dual batteries)" names no capacity for the second pack.
15. No ride of the DEFENDER 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.
16. 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.
17. Eunorau prints one saddle range without naming the frame. The review reads 35.0 to 40.9 inches as the 17-inch frame's, because its photograph of the 19-inch frame shows the saddle above 40.9 inches, and raises it 1.9 inches for the 19-inch along the measured post; if Eunorau's range is the 19-inch frame's, that frame's rows run lower.
18. The 19-inch frame is Eunorau's photograph, held to its table on three dimensions within 1.8%; the 17-inch uses the same post angle and grip, the grip moved 10 mm back by Eunorau's B difference.
19. The standover is measured on the 19-inch frame only, 2 inches ahead of the saddle's nose; the 17-inch's 29.1 inches is that figure less Eunorau's 49 mm H difference, derived, not measured.
20. The grip is read on the photograph at its photographed setting, and the sit bones are placed in the saddle's rear-middle quarter; moving the bar moves the lean and the hand load, and the hand figure is an upper figure for a relaxed back.
21. 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), and the heel check in the setup section gets closer.
22. The payload section quotes Eunorau's specification row, and the Mercer table names no statute. Expiry: re-verify if Eunorau changes the motor, the pack, the speed settings, the payload, the rider window, the saddle range, 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 the Eunorau DEFENDER a good e-bike?

For mixed pavement and dirt it gives you full suspension at 66 lb and $1,599, with about 55 miles at 12 mph on the throttle from one pack for a 180 lb rider. If your ground is steep and loose with a heavy load, the DEFENDER-S 2.0 adds a front hub (the family table).

What is the difference between the Eunorau DEFENDER and the DEFENDER-S?

The DEFENDER drives the rear wheel with one 500 W hub on 27.5 × 3.0 tires and weighs 66 lb; the DEFENDER-S 2.0 drives both wheels with two 750 W hubs on 26 × 4.0 fat tires and weighs 89.3 lb. Both have a fork and a rear shock and the same 300 lb payload (the family table).

Is 500W enough for an e-bike?

On the DEFENDER it is enough to hold 20 mph on the flat on the throttle, and 12.5 mph up a 6% grade with 180 lb aboard. It gets harder with weight on steep ground: from 260 lb up, a 12% grade needs your legs as well (the climb table).

How fast does a 500W electric bike go?

On the DEFENDER the setting sets the speed: 20 mph locked, with a 28 mph setting Eunorau describes "for off-road use". On the flat the modeled hub carries a 180 lb rider to 20 mph on the throttle, and the 28 mph section covers where the higher setting fits.

Can a 500W e-bike climb a hill?

Yes: on the throttle alone the DEFENDER's modeled hub holds 15.3 mph up a 4% grade and 10.4 mph up an 8% grade with 180 lb aboard. Pedal in a low gear on anything steeper, and plan about 149 to 183 Wh for each 1,000 feet you climb (the hill tables).

Are full-suspension e-bikes worth it?

If your rides include dirt, roots or broken pavement, yes: the DEFENDER's 100 mm fork and 165 mm rear shock take the hits your back and wrists would. If your rides stay on smooth pavement, weigh the 66 lb and the price against that ground; the family table sets Eunorau's options side by side.

What size e-bike should I get?

On the DEFENDER, the 17-inch frame suits riders below about 5'5" and the 19-inch most riders from 5'5" to 5'9". At 5'6" with a 31.7-inch inseam, the 19-inch saddle range covers 95 of 100 riders your height and 75 of 100 clear its top tube (the fit section).

How far can the DEFENDER go on a full charge?

About 55 miles at 12 mph on the throttle for a 180 lb rider on level pavement, 35 at 18 mph and 30 at 20, from the 720 Wh pack. Plan on 47 at 12 mph with 15% kept, and 94 with the 15 Ah second pack (the speed table).

What battery does the DEFENDER use?

A 48V 15Ah pack, 720 Wh, charged on a 2 A charger in about 7.5 hours from empty by our arithmetic. Eunorau's 15 Ah second pack adds another 720 Wh and 9.9 lb for $598.80 from us, and its listing names the Defender with no lock-out note (the frame section).

Can I buy a replacement or second battery for the Eunorau DEFENDER?

Yes: the 48V 15Ah pack Eunorau lists for the DEFENDER is $598.80 from us. Eunorau's pack listing names the "Defender" among its bikes (the frame section).

What accessories fit the Eunorau DEFENDER?

Eunorau lists the 48V 15Ah second battery and three trailers among the DEFENDER's compatible accessories, and we stock each one. The payload section links the trailers, $336.00 to $376.80, for loads you would rather tow than carry.

Can the DEFENDER pull a hunting trailer?

Eunorau lists its hunting trailer, its two-wheel hunting trailer and its one-wheel cargo trailer as compatible with the DEFENDER. Keep you and what rides on the bike inside 300 lb; the climb table's speeds are for bike and rider alone, with no trailer behind (the payload section).

Is the Eunorau DEFENDER heavy?

Eunorau lists it at 66 lb, and in the family table only the URUS 2.0, at 61.7 lb, weighs less. Your 300 lb payload sits on top of that, and the second pack adds 9.9 lb within it.

Is a 27.5-inch bike for adults?

The DEFENDER's 27.5 × 3.0 wheels are sized for adults: Eunorau's rider window runs from 5'3" to 6'4". Your inseam decides between its 17-inch and 19-inch frames (the fit section).

Is a 500W Class 2 e-bike legal in every state?

Not in every one: on October 2, 2026 the DEFENDER's printed figures sat inside 48 of 51 definitions. New Jersey treats any throttle bike as a motorized bicycle that needs registration, a license and insurance, and Alaska and Kentucky write no definition (the law section).

What warranty does the DEFENDER come with?

Eunorau's policy gives the frame 10 years and the battery, motor and electrical parts 24 months, for bikes bought in the US. Buy it from us and we run the claim with Eunorau for you (the warranty section).

Are Eunorau bikes good?

You can judge Eunorau by its parts, because it names them: on the DEFENDER a ZOOM fork, an EXA shock, a Shimano shifter, 180 mm hydraulic rotors, a 10-year frame warranty and a "UL CERTIFIED Yes" mark. Eunorau's DEFENDER page displays 163 customer reviews, 148 of them five stars, and our Eunorau brand profile covers the range.

The bottom line

The Eunorau DEFENDER is a $1,599 full-suspension e-bike with one 500 W rear hub, a 100 mm fork, a 165 mm rear shock, seven gears, 180 mm hydraulic brakes and a 720 Wh pack, rated to 300 lb, at 66 lb, in a 17- or 19-inch frame: inside 48 of 51 jurisdictions' e-bike definitions on October 2, 2026.

On the throttle a 180 lb rider covers about 55 miles at 12 mph, 35 at 18 and 44 at 12 mph with the full 300 lb, and the hub holds 12.5 mph up a 6% grade. Buy it for gravel, dirt paths, broken pavement and light trails; take the 17-inch below about 5'5" 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 — product page and product record: highlights, specification rows, notes, the geometry table and drawing for both frames, the feature copy, the compatible accessories and the studio gallery. eunorau-ebike.com/products/defender; product record defender.json. Retrieved October 2, 2026 (the specification rows equal the September 26 read, row for row); deposit copies archived.
2. Eunorau. DEFENDER-S 2.0 product page and record: two 750 W hubs, 85 N·m, the 75 mm fork and air shock, nine speeds, 26 × 4.0 tires, 89.3 lb and the 300 lb payload. defender-s. Retrieved October 2, 2026; deposit copies archived.
3. Eunorau. SPECTER-ST 2.0 product page and record: the Bafang M620 mid-drive with 160 N·m, the 140 mm fork and DNM AO-38RC shock, SRAM NX 11-speed, 27.5 × 3.0 tires, 88 lb and the 300 lb payload. specter-st-1. Retrieved September 26, 2026; deposit copies archived.
4. Eunorau. FAT-HS (Hunter X8) product page and record: the Bafang M615 mid-drive with 160 N·m, the RST GUIDE 75 mm fork and KS-388RL shock, nine speeds, 26 × 4.0 tires, 77.1 lb in the specification and 79.4 lb in the geometry table, and the 300 lb payload. fat-hs. Retrieved September 26, 2026; deposit copies archived.
5. Eunorau. URUS 2.0 product page and record: the Bafang M600 mid-drive with up to 120 N·m, the RockShox Psylo 150 mm fork and Deluxe Select+ RL shock, SRAM NX 11-speed, Maxxis 27.5 × 2.8 tires, about 61.7 lb and the 300 lb payload. urus. Retrieved September 26, 2026; deposit copies archived.
6. Eunorau. EUNORAU Universal 48V15Ah Secondary Battery, product page and record: $499, 9.9 lb, Samsung cells, and its list of compatible bikes, "Defender" among them. eunorau-48v15ah-second-battery. Retrieved October 2, 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. 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. Read for the screen of October 2, 2026.
9. 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 screen of October 2, 2026.
10. Pennsylvania General Assembly. 75 Pa.C.S. § 102, the definition of a "Pedalcycle with electric assist", including the weight limb "weighing not more than 100 pounds". palegis.us. Read for the screen of October 2, 2026.
11. New Jersey Legislature. P.L.2025, c.285 (S4834/A6235), the amended definitions of the low-speed electric bicycle and the motorized bicycle, signed and effective January 19, 2026. pub.njleg.gov. Read for the screen of October 2, 2026, through our 51-jurisdiction rule table.
12. Redtail eBikes editorial desk. The 51-jurisdiction rule table and its dated changes, and the two DEFENDER screens. Every US state and DC, each row carrying its statutory citation and source; screened October 2, 2026 on Eunorau's 500 W, the throttle and its 66 lb: at 20 mph (inside 48, outside 1, New Jersey; no definition in Alaska and Kentucky) and at 28 mph (inside none). First-party datasets.
13. Oregon Legislature. ORS 801.258, the three classes of electric assisted bicycle; Class 2 "Ceases to provide assistance once the bicycle reaches a speed of 20 miles per hour". oregonlegislature.gov. Read for the screen of October 2, 2026.
14. 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; deposit copies archived.
15. 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; and the full list of 10,027 recalls, June 8, 1973 to September 24, 2026, read for "Eunorau" and "Defender" on whole words after the model-name queries returned HTTP 503. Screens and the list archived.
16. 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 or the DEFENDER.
17. UL Standards & Engagement (standards body; context only). UL 2849 and UL 2271. Retrieved August 29, 2026.
18. Eunorau Bikes. 24-Month+ Limited Warranty: coverage periods, requirements, exclusions, the issuing entity and its scope, US purchases on or after August 1, 2023. eunorau-ebike.com/pages/warranty. Retrieved September 26 and October 2, 2026, unchanged between the two; deposit copies archived. With it, Eunorau's Warranty Policy, the original limited warranty for bikes bought before that date (5-year frame, 2-year prorated battery, 12-month components). eunorau-ebike.com/pages/eunorau-warranty. Retrieved October 2, 2026; deposit copy archived.
19. Redtail eBikes. DEFENDER store record (redtailebikes.com/products/eunorau-defender): the two colors and two frames, prices, orderability and the Shop Pay plan table; the 48V 15Ah second pack and the three trailers; the DEFENDER-S 2.0, SPECTER-ST 2.0, FAT-HS, URUS 2.0, FAT-AWD 2.0 and FLASH LITE ST prices; and our shipping policy. Read October 2, 2026.
20. Affirm. Lending partners. affirm.com/lenders. The lenders behind Shop Pay's installment plans, named in Shopify's installment terms.
21. Connecticut General Assembly. Public Act 26-24, § 26, the electric-bicycle definition's motor limb, effective October 1, 2026. cga.ct.gov. Read for the screen of October 2, 2026.
22. 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.
23. 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.
24. 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 (drag area by bicycle type); doi 10.1080/02640414.2018.1458587. civil-reactlab.sites.olt.ubc.ca. Retrieved September 23, 2026.
25. 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); doi 10.3390/wevj12020059. mdpi-res.com. Retrieved September 23, 2026.
26. Bicycle Rolling Resistance. Fat-bike tire tests (ten 26 × 4.00 tires on the drum at 12 psi). bicyclerollingresistance.com. Retrieved September 25, 2026; deposit copy archived.
27. 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.
28. 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.
29. 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.
30. Sheldon Brown and John Allen (Harris Cyclery). Tire Sizing Systems, the ISO/E.T.R.T.O. chart: the 584 mm bead seat of a 27.5-inch tire. sheldonbrown.com. Retrieved September 28, 2026; deposit copy archived.
31. 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.
32. 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.
33. 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.
34. 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.
35. 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.
36. 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.
37. 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.
38. 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.
39. 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.
40. Redtail eBikes editorial desk. DEFENDER range model. The computation set out in the range section of this review: Martin et al.'s power model with Bafang's RM G0H0 curve wound for Eunorau's 48 V and 500 W, capped at 60 N·m and fitted to its 20 mph locked setting, on a 28.99-inch 27.5 × 3.0 wheel and the median of ten wide tires; Eunorau's 80 miles mapped to a ride; run October 2, 2026. First-party computation; every input and its source in its inputs table.
41. Redtail eBikes editorial desk. DEFENDER fit model, two frames. Eunorau's drive-side photograph of the 19-inch frame, scaled by its 1,316 mm wheelbase and held to three of its table's dimensions within 1.8%; the seat post's axis fitted on 41 rows; Eunorau's 35.0 to 40.9 inch saddle range read as the 17-inch frame's and raised by the 19-inch frame's longer seat tube; the standover measured on the 19-inch frame; 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.