Ridstar Q50 Review: 1,200 Wh in One Pack

Moped-style fat-tire e-bike · one motor Ridstar prints as 2000 W and as 1500 W · one 48V 25Ah pack, 1,200 Wh · 20 × 4.0 tires, front fork and rear shock, hydraulic brakes · 330 lb load, riders 5'4" to 6'2" · 28+++ mph in its text, 25 mph on its panel · $918.85 on October 14, 2026 · verified October 14, 2026

Quick Answer — The Ridstar Q50 is a $918.85 moped-style fat-tire e-bike with one motor and one 48V 25Ah pack, 1,200 Wh from Ridstar's own figures, for riders 5'4" to 6'2". A 180 lb rider on level pavement computes to 64 miles at 15 mph with no pedaling; Ridstar prints 100 miles in pedal-assist mode.

Ridstar prints six range figures for this pack, 50 to 100 miles, and the range section maps each to a ride. Check three things before you order: how your state defines a 2,000 W motor (class), the weight Ridstar does not publish (weight and load), and Ridstar's after-sales statement beside our warranty answer (buying it from us).

The maker's record, before you buy. The Consumer Product Safety Commission issued two stop-use warnings in 2026 for Ridstar e-bikes made by Huizhou Xingqishi Sporting Goods Co., Ltd. of China: 26-337, for the Q20 and Q20 Pro, over batteries and wires that can ignite, and 26-584, for the Q20 and Q20 Lite, over a front wheel that can detach. The Q50 is in neither, no Ridstar recall exists, and the record section quotes both warnings.

What this review covers

Specification · Which Q50 · Fit · Motor · Battery · Range · Weight and load · Brakes and lights · Suspension and tires · The Mercer fit test · UL · Recalls · The maker's record · Class · Where to ride · Green and red flags · Verdict · Checklist · Buying it from us · FAQ · Limitations · Bottom line · References

How we verified this Ridstar Q50 review

Every Q50 figure here was read on October 14, 2026 from Ridstar's ridstar.net 25AH listing, its 20AH listing and ridstar.com's listing with the US market selected, and from the six images they carry, two read at full size for their printed figures. The CPSC warnings, the UK report, the court dockets, the recall list and our store's price, stock, shipping, checkout and refund terms were read the same day.

Every figure is verified against Ridstar's published specification and recomputed where arithmetic is involved, and the range and fit sections name each input. We sell the Q50, so the red flags get the same care as the green ones.

Written by Milad Ghobadibeygvand, BScN (Western University, 2014). Corrections: support@redtailebikes.com.

Ridstar's Q50 specification, figure by figure

Ridstar prints three top speeds, two motor ratings, two torque figures and six range figures for the Q50, and the table prints what each of its pages says. The second column is our reading of each row, the third is the listing text, and the fourth is what Ridstar prints over its own gallery photographs.

Ridstar's studio photograph, the first image on each of its Q50 listings. The ring headlight is drawn lit, and the listing text does not describe it.

Read October 14, 2026 from Ridstar's ridstar.net 25AH listing, its 20AH listing and ridstar.com's listing; the panel figures were read at full size. Image numbers follow the 25AH listing's gallery order. The 20AH listing's text differs from the 25AH's only in its pack and its range figures.

Ridstar lists the Q50 twice on ridstar.net and once on ridstar.com. In US dollars on October 14, 2026, ridstar.net asked $759 for the 25AH bike and $699 for a 20AH listing titled "Q50/Q30", and ridstar.com, with its US market selected, asked $1,389 for its 25 Ah variant and $1,279 for its 20 Ah one.

Ridstar's own price for the 25AH bike was $799 on August 30, 2026 and $759 on each of our reads since, with the same range, motor and rider-height lines on the page. Ours is $918.85, and the buying section sets out what that difference buys and what it does not.

The 25AH listing prints a different range in its headline paragraph (65 and 100 miles) than in its spec block and FAQ (50 and 80), and a 2000 W motor in its opening bullet and its spec block against 1500 W in a later paragraph. Where Ridstar's pages disagree with each other this review prints both figures with their sources and never picks one, and the range section works out what each range figure asks of the rider.

Which Q50 is this? The 25AH one with a single pack

On our shelf the Q50 is Ridstar Q50 2000W 48V 25Ah, and it is the bike this review covers: the 25AH listing on ridstar.net and the 25 Ah variant on ridstar.com. Three other names sit close to it, and none is the same machine.

The 20AH bike shares the photographs and every line of text except its pack, 48V 20Ah and 960 Wh by arithmetic, and its range figures. Ridstar titles it "Q50/Q30" on ridstar.net, although its spec block gives the model number as "Q50".

The Q50 Lite is a different 1000 W bike. On October 16, 2026 ridstar.net listed it as the "Q50/Q30Lite 1000W 15.6AH" at $599 and ridstar.com as the "Q50 Lite 1000W 48V 15AH", and this review does not cover it. Our store sells it as the Q30 Lite, and our Ridstar Q30 Lite review sets out its three names and their figures.

Google offers "ridstar q50 pro" as a search, but neither Ridstar store lists a Q50 Pro: none of ridstar.net's 85 titles or ridstar.com's 55 names one on October 14, 2026, and the Pro names Ridstar does use belong to the Q20 Pro and the Q30 Pro.

The machine in Ridstar's photographs is a moped-style frame: a long bench seat with a black fairing ahead of it, a ring headlight, a down-tube pack printed with a white Ridstar wordmark, and a perforated silver panel in the rear triangle. Ridstar's listing calls it an "adult dirt bike", an "electric motorcycle" and an "electric mountain bike" in different paragraphs, and names no class for it.

Google suggests "ridstar q20 vs q50" as a search, so the table sets the Q20 beside the Q50 from Ridstar's own pages for the Q20 1500W and the Q50.

The Q20 column is from Ridstar's ridstar.com page as read October 12, 2026, and the Q50 column from the listings read October 14, 2026. Our prices were read from our store on October 14, 2026.

At our prices the Q50 costs 77 cents per watt-hour of pack and the Q20 109 cents. The two records differ as well: the Commission's warnings name the Q20 twice and the Q50 never.

If 1,200 Wh is more pack than you need, the Ridstar Q20 Lite review reads the Q20 family's smallest pack, 720 Wh, the Ridstar H26 Pro review a 960 Wh bike that folds, and the Ridstar MN26 review a 960 Wh step-through that does not. The Ridstar FM001 review covers Ridstar's two-seater and its single load limit for two. Our e-bike reviews gather Ridstar's bikes with every other maker we review.

Who the Q50 fits: Ridstar's 5'4" to 6'2" window

By the standard saddle formula, 109% of inseam from the pedal axle, a median 5'10" rider in the US Army's ANSUR II survey needs the saddle top 36.8 inches above the pedal, and a median 6'2" rider 39.3 inches. Ridstar prints one fit figure for the Q50, a rider window, and a window cannot say which bodies it suits: in the same survey, riders of one height differ by about three inches of inseam.

A crop of Ridstar's photograph: the bench, the fairing and the side panel. Ridstar prints no seat height or seat range for the Q50.

Ridstar's two stores write the window in two ways: ridstar.com prints "5'4" -6'2"" on its slider, and ridstar.net prints "5.4 to 6.2 feet" in its FAQ. This review reads both as 5'4" to 6'2"; taken as decimal feet, the ridstar.net figures would be 5'4.8" to 6'2.4".

Get your own figure in three steps:

1. Measure your inseam in stocking feet against a wall, with a book pressed up between your legs.
2. Find your height in the saddle table and read the saddle top to the pedal axle that matches your inseam.
3. Set the saddle with the heel check in the setup subsection, then bend the knee to the 25 to 35 degree target.

No geometry is published for the Q50: the listings and their six gallery images give no seat height, saddle range, standover, reach or crank length. The model therefore prints the formula and the window, and it does not compute a lean, a hand load or a clearance for a bike whose dimensions nobody has printed.

What seat height does the Ridstar Q50 need?

The saddle top goes at 109% of your inseam, measured from the pedal axle, the figure Peveler et al. (2005) compared with the heel method. Ferrer-Roca et al. (2012) give 106% to 109% as their recommended range and 108.6% to 110.4% from their equation, so the table prints 106% and 110.4% as its two ends.

The inseam bands are the middle 90% of the 6,068 bodies in the US Army's ANSUR II survey. Ridstar publishes no saddle range for the Q50, so the table shows where the formula puts your saddle, not whether the seat post reaches it.

The formula saddle table. Inseam bands are the middle 90% of ANSUR II bodies at each height, at least 30 per band. The 109% column is Peveler et al.'s figure, and the 106% and 110.4% columns are the ends of the Ferrer-Roca ranges. Ridstar publishes no crank length, so LeMond's 88.3% column is not computed.

What is the Ridstar Q50's standover height?

Ridstar prints no standover height for the Q50, so the clearance over its frame cannot be computed. For a sense of scale, the median inseam in the Army survey is 33.8 inches at 5'10" and 36.0 inches at 6'2".

Measure the bench height on the bike you receive before you count on both feet reaching the ground at a stop. The email offer above covers it before you order.

Will you sit stretched or cramped on the Q50?

The lean is not computed, because Ridstar publishes no grip position or reach for the Q50. The lean depends on both, and the studio photograph shows a bike without a rider on it. Sit on one at rest if you can; otherwise the email offer above takes your arm length too.

Weight on your hands

Hand load depends on where the grips sit, and no grip position is published for the Q50, so no hand load is computed. The one measured reference this page can cite is about 15% of body weight through the stem, from Carahalios (2015) on ten road racers with their hands on the hoods; it is a ceiling for a racer leaning forward, and no Q50 figure is computed from it.

What size is the Ridstar Q50?

Ridstar's listings offer one frame on 20 × 4.0 tires for riders 5'4" to 6'2", so the fitting happens at the seat post when the box opens.

Start with the heel check: sit with the heel on the pedal at the bottom of the stroke and the crank in line with the seat tube, and straighten the leg. If your hips rock on the bench, or the leg cannot straighten, the seat is too high.

Then pedal on the ball of the foot and aim for 25 to 35 degrees of knee bend at the bottom of the stroke, the target Peveler, Pounders and Bishop (2007) and Ferrer-Roca et al. (2012) bracket. Two riders of one height can need different settings, so treat the formula as the first guess.

The fit arithmetic, step by step

The model reads each body's inseam from ANSUR II and prints the saddle top at 109%, 106% and 110.4% of it, from the pedal axle. Worked through for a 68-inch rider: the model's inseam at that height is 32.6 inches, so the 109% saddle sits 35.6 inches above the pedal axle, the 106% saddle 34.6 inches and the 110.4% saddle 36.0 inches.

At 109% the model gives the figure Peveler et al. (2005) report, 109.2 ± 0.9%. Ridstar prints no saddle range to check the output against, and Limitations lists that gap.

One 2,000 W motor in the rear wheel

Ridstar's own graphic draws the Q50's motor inside the rear wheel, and the listing rates it at 2,000 W in its spec block and at 1,500 W in its description. The spec block gives the motor as "2000W Motor", the next bullet says "a powerful 2000W brushless motor with a torque of up to 85Nm", and a later paragraph says "Equipped with a 1500W brushless motor".

The gallery's motor panel prints "2000W BRUSHLESS MOTOR" and "80n.m" for the torque.

A crop of Ridstar's studio photograph: the front wheel with its drilled disc and red caliper.

A crop of the same photograph: the rear wheel's hub, caliper and chain run, with the kickstand down.

Three speeds sit on Ridstar's pages. The ridstar.net text says "a maximum speed of 28+++ mph in pure electric mode", ridstar.com's slider says "Max Speed Tested 28 MPH" and its text "25-28mph", and the motor panel says "25mph".

Our range model rebuilds a published hub-motor curve, Bafang's RM G0H0, at 48 V and 2,000 W with its no-load speed set from Ridstar's 28 mph, and for a 180 lb rider on level pavement it holds 26.3 mph at most.

Ridstar claims climbs "up to 30°" on ridstar.net and "35-degree roads" on ridstar.com. A 30° slope is a 58% grade, and the model's steepest row is 15%, where the same rider holds a steady 10 mph on the motor alone; no measurement on the record checks Ridstar's angles.

Ridstar's own parts store sells the drive train for it. The throttle listing carries a "US / Q50" variant at $59, the motor listing a "US / Q50" variant at $209 and the controller listing one at $89, each in stock on October 14, 2026. The Q50's own listing says "Twist Grip Throttle" and names three riding modes: pure electric, electric assist and pedal.

Ridstar prints 2,000 W and 1,500 W for one motor, with no peak or continuous split for either. That rating decides how the law reads the bike: 44 of the 51 state definitions in our census set a 750-watt motor limb, and the Q50 sits above it at either figure. The range tables carry the 1,500 W reading as a sensitivity row.

One 48V 25Ah pack: 1,200 Wh

Ridstar's listing prints one removable 48V 25Ah pack, which is 1,200 Wh computed from 48V and 25Ah as published. At our prices that is 77 cents per watt-hour of pack, against 116 cents for the Samebike M20's 864 Wh and 193 cents for the VTUVIA SF20H's 672 Wh.

A crop of Ridstar's photograph: the one pack, 48V 25Ah, which is 1,200 Wh on Ridstar's figures.

The listing says "a removable 48V 25AH lithium-ion battery", and its gallery panel prints "REMOVABLE BATTERY" beside "Lockable", "Fast Charging" and "BMS Power Saving". The spec block gives "Charging Time: About 4-6 Hours" and no charger rating, so this review computes no charging current. The 20AH bike carries a 960 Wh pack, and the UL section sets out what the listing does and does not say about certification.

Filling the pack costs about 22 cents. At 18.31 cents per kWh, the US residential average for July 2026 in the Energy Information Administration's Table 5.6.A, 1,200 Wh comes to about 22 cents before the charger's losses. A rider who covers 1,000 miles a year at 15 mph with no pedaling, at the model's 18.7 Wh a mile, spends about $3.42 a year on the same basis.

The maker sells a spare pack. Ridstar's parts store lists a "US / Q50 25AH" variant at $379, in stock on October 14, 2026, under a product titled "Ridstar Q20/DC26/H20 48V 20AH 15AH Removable Electric E-Bike Battery". That is 41% of our price for the whole bike and 32 cents per watt-hour.

Range: how far 1,200 Wh carries the Q50

On level pavement, a 180 lb rider on a Q50 modeled at 92.6 lb computes to 64 miles at 15 mph with no pedaling, 47 miles at 20 mph and 91 miles at 15 mph with easy pedaling, on a full pack. Each 1,000 feet of climbing on the throttle costs the pack about 133 to 154 Wh, depending on the grade, so a hilly route shortens the ride faster than its length suggests.

A crop of Ridstar's photograph: the cockpit. The listing names a twist-grip throttle and an LCD that shows speed, mileage, battery level and pedal-assist level.

Get your own figure in three steps:

1. Find your cruising speed and how hard you pedal in the speed tables.
2. Add the climb cost of your route from the hill table, about 133 to 154 Wh for each 1,000 feet on the throttle.
3. Correct for your weight with cargo and the air temperature, then plan on the column that keeps a quarter of the pack in reserve.

Every number in this section comes from one steady-state model. Its inputs are Ridstar's own figures, a comparable motor's published curve, measured fat-tire rolling resistance and a peer-reviewed cycling-power model, and the formula subsection walks one ride through it so you can check the arithmetic.

How much range does the Ridstar Q50 have?

On flat pavement with no pedaling, a full pack computes to 64 miles at 15 mph and 47 miles at 20 mph for a 180 lb rider, and the tables below show how each step in speed, pedaling, load and weather moves that figure.

The first table pairs the throttle ride with the planning column, and the second shows what steady pedaling adds at each speed. Both use level pavement, the 180 lb rider, a 92.6 lb bike and 77 °F.

Miles on a full 1,200 Wh pack, flat pavement, 180 lb rider, 92.6 lb bike, 77 °F, tires at the median rolling resistance of ten fat-tire tests. The last column keeps 25% of the pack in reserve, the share left after Schmitt, Decker and Doppelbauer (2019) measured a pedelec using 75% of its nominal pack; Ridstar publishes no reserve for this model.

Miles on a full pack at each effort, flat pavement, 180 lb rider, 92.6 lb bike. "Easy pedaling" adds 75 W of rider power and "steady pedaling" 150 W. The throttle column is the first table's.

At Ridstar's 28 mph the model's motor cannot hold the speed on the flat: its fastest steady speed for a 180 lb rider is 26.3 mph, so the tables stop at 25 mph, where the bike still covers 35 miles on a full pack with no pedaling.

Pedaling alone would hold the bike at 8.8 mph with 75 W and at 12.9 mph with 150 W, which is why the effort table starts at 15 mph.

What gears does the Ridstar Q50 have?

Seven speeds: Ridstar's listing names a "Shimano 7-speed Transmission System". The motor sits in the wheel, so the gears change your cadence and what your legs add, and no cog choice changes what the motor draws.

The table therefore shows the energy each ride needs at three efforts, and it is not a gear chart. Pick the gear that lets you hold your effort; the pack feels the difference in your watts and not in your cog.

Watt-hours a mile from the pack on the flat and on two grades, 180 lb rider, 92.6 lb bike, at three efforts. The 12 mph rows show what a grade does to a slow ride.

Climbing and the pack

Each foot you climb draws on the pack at a rising rate. On the throttle alone, climbing costs about 133 Wh per 1,000 feet at a 4% grade, 139 at 6%, 146 at 8% and 154 at 10%. At a steady 10 mph the cost of a mile rises from 27 Wh at 2% to 152 Wh at 15%.

Full-pack miles by grade at a steady 10 mph, 180 lb rider, 92.6 lb bike, on the throttle and with easy pedaling. The grades run from 2% to 15%.

Ridstar's "30°" is a slope of 58% grade, far beyond the table, and the listing prints no speed or load for it. The model's motor holds every grade in the table at 10 mph.

What is the Ridstar Q50's weight limit?

Ridstar prints "maximum load capacity of 330 lbs", and every pound you bring toward it shortens the ride. On the flat at 15 mph, going from a 100 lb load to Ridstar's 330 lb takes the pack from 72 miles to 54 miles. The 8% climb at 10 mph shows the larger drop, from 23 miles to 9.

Rider plus cargo, 92.6 lb bike, on the throttle, flat pavement unless the column says climb. The heaviest row is Ridstar's own 330 lb maximum load, read as the rider and cargo the bike carries; Ridstar does not define it further.

The bike's own weight is the one input Ridstar does not publish, so the model runs it at a bracket: 92.6 lb, the weight Ridstar prints for its Q30 Luxe, which carries the same 48 V, 2,000 W motor rating, 20 × 4.0 tires and one pack at 20 Ah, and 66 lb, the weight Ridstar prints for its Q20 1500W. The lighter case adds two miles at 15 mph.

A 180 lb rider on the throttle, flat pavement unless the column says climb, at the two published weights. The first row is the one every other table uses.

Cold and the pack

The cold table uses the cell data of a representative 18650 lithium cell, because Ridstar names no cell for the Q50. At 32 °F the model gives 52 miles at 15 mph with no pedaling for a 180 lb rider, within a bracket of 46 to 54 miles; at 14 °F it gives 47 miles, within 23 to 47.

Air temperature, the pack's energy against 77 °F, and the 15 mph flat range with no pedaling, 180 lb rider. Brackets are the spread across the cell data read; below freezing the sources disagree most.

Tires and riding position

The tires move the range a little. The model uses the median rolling resistance of ten fat-tire tests on a drum (0.0105), bracketed by the lowest of the ten (0.0070) and the highest, a knobby Kenda Juggernaut Pro (0.0126). Ridstar's listing names no tire maker, so the bracket covers the range the drum recorded.

Position is the other term. The model uses 0.640 m² for the frontal area of an upright cruiser, from Tengattini and Bigazzi (2018), because Ridstar does not publish the Q50's riding position. Sit lower and the drag falls, which adds range.

Rolling resistance as the drum measured it, with the 15 mph and 20 mph flat ranges on the throttle for a 180 lb rider on the 92.6 lb bike.

How many miles of range does Ridstar give the Q50?

Ridstar prints six range figures for the Q50, from 50 to 100 miles, and the model reproduces each one as a ride: the two pure-electric figures at 14.8 mph (65 miles) and 19.2 mph (50 miles) with no pedaling, and the four assist figures with 75 W or 150 W of pedaling. The table gives the steady speed at which a 180 lb rider on the 92.6 lb bike reaches each figure on flat pavement.

The steady flat-pavement speed at which the model reaches each of Ridstar's range figures on a full 1,200 Wh pack, at three efforts. The sources are the ridstar.net headline, spec block and FAQ, its gallery image 2, and ridstar.com's slider.

None of the six prints a speed, a rider weight or a terrain beside it. The 100 miles in the headline, for example, asks for 14.3 mph with 75 W of easy pedaling, or 17.4 mph with 150 W: the rider's legs carry a large part of that ride, so read it as the reach of a pedal-led day.

For a ride with the throttle doing the work, the speed table is the figure to plan on.

The formula behind the range tables

The power at the wheel is the rolling resistance, plus the climb, plus the aerodynamic drag, and the motor and battery losses are added on top. The model uses the cycling-power form of Martin et al. (1998): power equals speed times the sum of the rolling term, the gravity term and the drag term, divided through the drivetrain, motor and battery efficiencies.

The inputs, each with its source. A number with no row here does not enter the model.

Each row is a published input, a comparable with its bracket, or a constant, and each is read in the model's own provenance block. Sources are in the references.

One ride, worked through step by step. At 15 mph on flat pavement with no pedaling, a 180 lb rider on the 92.6 lb bike: the rolling term takes 86 W, the drag 114 W, and the wheel receives 200 W. The motor runs at about 74% efficiency at that load, so the battery supplies 272 W, and with the battery's own losses at 97% the cells give up 280 W.

At 18.7 Wh a mile, 1,200 Wh carries the bike 64.2 miles, and the planning figure is 48.1 miles.

The model reproduces Martin et al.'s Appendix I values, 45.7 W for the rolling and potential terms and 158.8 W for the aerodynamic term, to the printed digit, and its comparable motor gives 80% at its rated point, the Bafang workbook's published floor. No measured ride of a Q50 checks the output, which is the gap Limitations names.

The motor assumption alone moves the 15 mph figure from 64 to as much as 74 miles. If the motor behaved like a comparable rated at 750 W, the 15 mph ride reads 69 miles instead of 64, and 49 instead of 47 at 20 mph; at the 1,500 W rating in Ridstar's description it reads 67 and 49, and at 82% motor efficiency 74 and 53.

All the cases come from the same inputs, none is a measurement, and the central figure is the lowest of them.

Weight and load: no bike weight, and 330 lb on board

Ridstar prints a 330 lb maximum load for the Q50 and no weight for the bike. The listing says "Max Load: 330lbs" and "a maximum load capacity of 330 lbs", and the weight field in Ridstar's store records for all three Q50 listings reads zero on August 26, September 17, October 12 and October 14, 2026.

The two published weights closest to the Q50 in motor, tire and pack are 92.6 lb for the Q30 Luxe and 66 lb for the Q20 1500W, and the 26 lb between them is the size of the unknown. It is the number to settle before you order if the bike will live up a flight of stairs or ride on a hitch rack.

If you lift the bike, get its weight in writing before you order. The email offer in the fit section covers it: send the stairs or the rack you have in mind along with your height, and our written answer comes before you pay.

Brakes, lights and display

Ridstar lists hydraulic brakes on both wheels: its spec block gives "Hydraulic Dual Brakes". The listing adds "The hydraulic dual brakes system reduces the average braking distance by 50% compared to mechanical brakes", a comparison for which it prints no test, and the photographs show a red caliper on each wheel, a drilled disc at the front. Ridstar prints no rotor size and no brake maker.

The parts store lists a front brake set and a rear brake set for the Q50 in "US / Left front brake / Q50" and "US / Right rear brake / Q50" variants at $90 each, and a front fork at $189, in stock on October 14, 2026.

The lights are "bright LED headlights and IP5 waterproof protection" in the listing's words, and the gallery's last image draws the headlight lit above a red tail light.

The display is "an advanced LCD that provides real-time metrics, adjustable parameters, and various trip-tracking options" on ridstar.net, and ridstar.com lists "speed shifts, mileage data, battery prompts, gear switching" among its readouts. The listing also names a 7.2-inch phone holder and a storage box of 22 × 14 × 11 cm.

Ridstar's gallery image 6, scaled down: the headlight and the tail light, both drawn lit. The listing gives no lumen figure for either.

Suspension and tires

Ridstar fits a front fork and a rear shock and puts the bike on 20 × 4.0 tires. The listing says "The front suspension fork is strengthened by 100%, making it easier to navigate rough terrains" and "The rear hydraulic shock absorber offers superior performance compared to mechanical models", and prints no travel for either.

Ridstar's gallery image 5: the fork damper and the coil rear shock, with the orange glow the graphic adds. It prints no travel figure.

The tires are "20-inch x 4.0 wide tires" that the listing calls "puncture-resistant", for "grass, dirt, sand, snow, and gravel". Ridstar names no tire maker and prints no pressure. Our range model brackets the rolling resistance between the lowest and the highest of ten measured fat tires, and the rider's weight and the hills move the range more than the tires do.

The Mercer fit test

Seven members of the Mercer family, the fixed archetypes we hold every reviewed bike against, are set against the Q50. Each row reads Ridstar's window, the model's saddle figure for that height, the load rating or the law in the class section; the people are archetypes and never testers.

The people are the Mercer family. Heights and ages are theirs; the saddle figures are the model's at each height, from the ANSUR II survey.

All five adult Mercers fall inside Ridstar's 5'4" to 6'2" window, and the line runs between them and the two youngest. Ruth at 5'5" sits near the bottom of the window and Jack at 6'1" near the top, and the bench height is not published, so both should sit on the bike or ask before ordering.

Cole is 16 and Ivy is 12, and on Ridstar's own figures the bike sits above the e-bike limits in the class section, so neither row is a yes.

Is the Ridstar Q50 UL certified?

None of Ridstar's three Q50 listings, and none of the 18 images on them, prints a UL standard, a certificate holder or a file number for the bike, the pack or the charger. UL Solutions certifies e-bikes to UL 2849, which examines the drive train, battery and charger as one system. The two ridstar.net listings list "US trademark", "CE trademark" and "European trademark" under "Our Qualifications", and none of the three names a safety standard.

A certificate has a holder's name and a UL file number, and a seller can be asked for both before you pay. If a certificate on paper decides your purchase, VTUVIA's SF20H page prints "UL2271 & UL2849 Safety Certified" beside its specifications, and the same two questions apply there.

Has the Q50 been recalled?

No. The CPSC's recall list carries no Ridstar recall of any model, and the Commission's two Ridstar warnings name the Q20, the Q20 Pro and the Q20 Lite, and not the Q50. On October 14, 2026 the whole recall list, 10,047 records to the newest recall of October 8, 2026, held no Ridstar, Xingqishi, HK Ridstar or YVY term and no record naming a Q50, and the Commission's recall feed of 40 items held none either.

A warning is not a recall, and no recall also means no recall remedy for any Ridstar model. The CPSC recall search is the place to check the bike again before you buy, and the next section sets out what the two warnings say.

The maker's record

Two CPSC stop-use warnings, a UK safety report and two lawsuits concern Ridstar bikes, and none of them names the Q50. The record concerns the company you would be buying from, so it is set out here in full, in the regulators', the courts' and Ridstar's own words as they printed them.

Both rows as the Commission printed them, re-read word for word on October 14, 2026.

The Commission names the manufacturer in both releases as Huizhou Xingqishi Sporting Goods Co., Ltd., of China. The first says it "has refused to agree to an acceptable recall", and the second that it "has been unresponsive to CPSC's requests for information about these products or a recall." The first also prints the company's reply: "The company objects to this press release."

What the record does not say. Neither warning names the Q50, and neither the Commission nor Ridstar publishes whether the Q50 shares the warned bikes' batteries, wiring or front-wheel hardware.

Both releases tell owners how to identify the bikes: they are black, "the brand name Ridstar is printed on the battery", and the model number sits "on the purchase receipt", "Q20 or Q20 Pro" in the first and "Q20 or Q20 Lite" in the second.

The Q50 in Ridstar's photographs is black and carries the Ridstar name on its pack, so if you own any Ridstar, the model number on your receipt is the line to read, and the Commission names only those three models.

Britain has its own record. The Office for Product Safety and Standards reported Ridstar's "Q20-Plus, Q20-Mini, E26 Pro and Chargers" as a serious fire risk on June 19, 2025, because "the charger has poor quality soldering, and the transformer does not meet the minimum requirements for creepage and clearance distances." The import "has been rejected at the border." The report does not name the Q50.

Two product-liability suits allege that a Ridstar front wheel came off: the Oregon suit against Amazon, No. 3:26-cv-00692, over a "Ridstar Q20", and the Florida suit against Walmart, No. 9:26-cv-81045, over a "Ridstar Electric Bike, Peak 1500W30MPH,48V 15.6Ah". Both are allegations, undecided on their dockets as of October 14, 2026. Neither names the Q50, and Ridstar is not a named defendant in either.

Who you would be buying from. Ridstar's company page names its business as "HK RIDSTAR TRADE LIMITED", at an address in Hung Hom, Kowloon, while the Q50 listing says "Established in New Jersey and proudly serving the US since 2008." YVY's own company page names the same business, HK Ridstar Trade Limited, so YVY and Ridstar bikes come from one company.

Which Ridstar store you would be buying from. ridstar.net prints "Official Statement of Ridstar: Except ridstar.net, other similar websites are our dealers" and "The only official website of ridstar", while ridstar.com's listing says "The Ridstar Warranty Policy is only available to customers ordering from ridstar.com."

A first-time buyer put the question on r/ebike on August 9, 2026: the same Q50 was "$1.4K" on ridstar.com and "6 hundred dollars less" on ridstar.net. On October 14 the 25AH bike cost $759 on ridstar.net and $1,389 on ridstar.com, and the buying section sets out what that gap means for a bike bought from us.

No e-bike class fits the Q50's figures

On Ridstar's own figures, a 2,000 W motor, or a 1,500 W one, and a top speed of 28+++ or 25 mph sit outside the definitions the e-bike classes are built on, and Ridstar's pages assign the Q50 no class. Read your state's definition before any ride on a public road, lane or path.

At the federal level, 15 U.S.C. § 2085(b) defines a low-speed electric bicycle as one with "fully operable pedals and an electric motor of less than 750 watts (1 h.p.), whose maximum speed on a paved level surface, when powered solely by such a motor while ridden by an operator who weighs 170 pounds, is less than 20 mph."

Statute text read October 12, 2026 at govinfo and California's legislative site; Ridstar's figures from its listings and gallery, read October 14, 2026.

In California the motor alone takes the Q50 outside the electric bicycle definition at either rating, because § 312.5(a) tests a motor that "does not exceed 750 watts of power" and Ridstar prints 2,000 W and 1,500 W. Neither figure is split into a rated and a peak value on the listing, and the statute does not say which one counts.

The code's definition of a motorized bicycle or moped, § 406(a), asks for "fully operative pedals", "an automatic transmission" and "a motor that produces less than 4 gross brake horsepower" with a top speed "of not more than 30 miles per hour on level ground".

A 2,000 W motor is about 2.7 horsepower and a 1,500 W motor about 2.0, and Ridstar's 25 and 28 mph sit under the speed limb, though its "28+++" leaves the figure open.

Ridstar names a "Shimano 7-speed Transmission System", and whether that is "an automatic transmission" is a question for the California Department of Motor Vehicles and our California page; this review does not decide it.

Our census of the 51 state definitions, the 50 states and DC, read September 24, 2026, found 44 that set a 750-watt motor limb, California's among them, and Rhode Island's "rated not more than two (2) (S.A.E.) horsepower", about 1,491 W. The Q50's 2,000 W is above all 45 of those limbs, and at its 1,500 W it is above the 44 that set 750 watts.

Four definitions set no power figure, the District's, Montana's, New Jersey's and Oregon's, and Alaska and Kentucky define no electric bicycle. Our 50-state atlas sets out each one from its statute, with the speed limits that decide a bike in the states that set no wattage.

Where you can ride it

A path or trail that admits e-bikes by class admits this machine only if its own posted wording says so, and on Ridstar's figures no class covers the Q50. In California, if the bike is read as a motorized bicycle, § 21207.5(a) keeps it off "a bicycle path or trail, bikeway, bicycle lane" unless the path is "within or adjacent to a roadway" or a local ordinance permits it.

Each rulebook reads its own posted wording first, and the specification matters once that wording names watts or speed.

National Forest rules define a motor vehicle as "any vehicle which is self-propelled, other than" a vehicle operated on rails or a wheelchair or mobility device (36 CFR 261.2), and a breach of a Part 261 rule carries "imprisonment of not more than six months or a fine in accordance with" the federal criminal code (36 CFR 261.1b). Our public-land guide covers each federal land agency.

Green flags / Red flags

The green flags are checkable facts on Ridstar's pages and ours. Each red flag ends in something you can do before you buy or ride.

Green flags

• One 1,200 Wh pack for $918.85. About 77 cents per watt-hour at our price, against 109 cents for our Q20 listing and 116 for the Samebike M20.
• In stock at the maker and buyable here. Ridstar's ridstar.net listing and its ridstar.com US variant both showed the 25AH bike in stock on October 14, 2026, and our listing took orders that day.
• A fit window and a load rating are published. Ridstar's pages print 5'4" to 6'2" and a 330 lb maximum load.
• The maker sells the parts. Ridstar's store lists Q50 variants of a 25AH pack, a motor, a controller, a throttle, two brake sets and a fork, all in stock that day.
• Hydraulic brakes, a front fork, a rear shock and seven speeds, in Ridstar's own words.

Red flags

• On Ridstar's own figures no e-bike class covers it. Read your state's definition first; for a 750 W bike inside a class, look at the VTUVIA SF20H.
• Ridstar prints two motor ratings, three top speeds and six range figures. Email us and we will ask Ridstar which ones it measured, in writing, before you order.
• Ridstar prints no bike weight, seat height or geometry. The weight section brackets the bike at 66 to 92.6 lb and the fit section prints the saddle formula, so measure your inseam and get the weight in writing before you order.
• The maker's record includes two CPSC warnings on other models and no recall. Read the record; for the same kind of machine from a maker no notice names, look at the Samebike M20.
• Ridstar's official statement limits its after-sales service to ridstar.net buyers. Read our warranty answer and ask us in writing which terms apply before you buy.
• No UL standard, certificate holder or charger rating is printed. The UL section says what to ask a seller for, and the VTUVIA SF20H prints "UL2271 & UL2849 Safety Certified".

Buy it if / Buy something else if

Buy it if you want one big pack on a moped-style fat-tire bike, you are 5'4" to 6'2", and you ride where your state's rules take a motor Ridstar prints at 2,000 W and at 1,500 W. At $918.85 the pack costs about 77 cents per watt-hour, and charging for 1,000 miles a year at 15 mph with no pedaling costs about $3.42 a year.

Buy something else if you ride bike lanes or paths that admit e-bikes by class. The VTUVIA SF20H, $1,299 on our store on October 14, 2026, prints "750W Motor Power" and "UL2271 & UL2849 Safety Certified" on VTUVIA's page, lists "Speed Class 2" among its specifications, and has a 672 Wh pack and a 60 lb net weight that includes its rear racks and fenders.

VTUVIA showed the SF20H in stock in White and Black that day, and our SF20H review computes its range and fit for your height and route.

Buy something else if you want the same kind of machine from a maker no CPSC notice names. The Samebike M20, $999 on our store, has a "1800W Peak Motor" and a "48V 18Ah" pack, 864 Wh by arithmetic, on Samebike's page.

Samebike showed it in stock in Peru on October 14, 2026. Its printed figures sit above the 750-watt line as the Q50's do, so the class question is the same, and our M20 review computes its range and fit.

Buy something else if you need the store that sold you the bike to hold the maker's warranty. Ridstar's statement and our policy are set side by side in buying it from us; ask us in writing before you order.

Before you buy: the checklist

Six checks cover the Q50: your state's definition, your inseam and the bench, the weight Ridstar does not print, the maker's record, the figures to ask for, and the first week of riding.

1. Read your state's definition and the posted class wording on any path you plan to use, in our atlas.
2. Measure your inseam and read your row in the saddle table before you order.
3. Settle the weight if you lift the bike: the bracket runs from 66 to 92.6 lb, and the figure you need is the one in writing.
4. Read the maker's record and our warranty answer, and ask us anything they leave open.
5. Ask for the missing figures in writing: which motor rating is the measured one, the top speed, the charger rating, and a UL certificate holder and file number if you want one.
6. In the first week, inspect the delivery within 48 hours, check that the axle nuts are tight, and set the saddle with the heel check.

Buying it from us

Our Q50 listing was open at $918.85 on October 14, 2026, and here is what we do for that price. Every row is a thing we do, read from our own store that day.

Read October 14, 2026 from our shipping policy, our refund policy and our checkout.

Change-of-mind returns are for unopened bikes in factory-sealed packaging, requested within 72 hours of delivery, with a 15% restocking fee and the return freight, and an order cancellation carries a 3% transaction fee, as our refund policy sets out.

Who repairs it is the question to settle before you buy. Ridstar's official statement says: "Except for customers who purchase from ridstar.net, we will not provide any after-sales service to customers who purchase ridstar products from other places." Our refund policy says a power, charging or component fault "is covered under manufacturer warranty — we coordinate repair or replacement remotely."

For a bike bought here those two statements do not agree, and this review does not settle the disagreement. Ask us in writing which applies to the unit you are offered, and we will answer before you order.

Frequently asked questions

What is the Ridstar Q50?

The Ridstar Q50 is a moped-style fat-tire electric bike that Ridstar lists on ridstar.net and on ridstar.com. Ridstar prints one hub motor as 2,000 W and as 1,500 W, one removable 48V 25Ah pack that is 1,200 Wh by arithmetic, 20 × 4.0 tires, a front fork and a rear shock, hydraulic brakes, seven speeds and a 330 lb maximum load. The specification table quotes each figure with its source.

How fast does the Ridstar Q50 go?

Ridstar prints three figures: "a maximum speed of 28+++ mph in pure electric mode" on ridstar.net, "Max Speed Tested 28 MPH" and "25-28mph" on ridstar.com, and "25mph" over "Top Speed" on its gallery panel. The range model's motor holds 26.3 mph on flat pavement with a 180 lb rider. No measured top speed is published, so ask for one in writing before you rely on any of the three.

How far can the Ridstar Q50 go on one charge?

The model computes 64 miles at 15 mph with no pedaling, 47 at 20 mph and 91 at 15 mph with easy pedaling, on flat pavement with a 180 lb rider. Keep a quarter of the pack in reserve and plan on 48 miles at 15 mph with no pedaling. Ridstar prints six figures from 50 to 100 miles and no speed beside any of them, and the range section shows the ride each one asks for.

What are the Ridstar Q50's specs?

Ridstar prints one motor at 2,000 W and at 1,500 W; one 48V 25Ah pack, 1,200 Wh by arithmetic; 20 × 4.0 tires; a front fork and a rear shock; hydraulic brakes; seven speeds; a 330 lb load; and a 5'4" to 6'2" window, and it prints no weight. The specification table quotes each figure and each place Ridstar's pages disagree.

Is the Ridstar Q50 street legal?

On Ridstar's own figures its motor alone puts it outside the federal low-speed electric bicycle definition and outside California's electric bicycle definition at either rating, and it is above the 750-watt limb of 44 of the 51 state definitions we read. Your state decides whether and where a machine of this power may ride; the class section has the detail.

Is the Ridstar Q50 named in the CPSC warnings?

No. The Commission's two Ridstar warnings, on fires and on front wheels, name the Q20, the Q20 Pro and the Q20 Lite, and neither names the Q50. Neither the Commission nor Ridstar publishes whether the Q50 shares the warned bikes' parts, and no Ridstar recall exists; the record section quotes both warnings.

What is the difference between the Ridstar Q20 and the Q50?

Ridstar prints a 1,500 W motor and a 48V 20Ah pack for the Q20 1500W, and the Q50 listing prints 2,000 W in its spec block and 1,500 W in its description, on one 48V 25Ah pack. On October 14, 2026 our Q20 was $1,045.35 and our Q50 $918.85, 109 and 77 cents per watt-hour of pack, and the Commission's warnings name the Q20 twice and the Q50 never (the table).

Is there a Ridstar Q50 Pro?

No Ridstar store lists one. People search for it, but none of ridstar.net's 85 product titles or ridstar.com's 55 names a Q50 Pro on October 14, 2026; the Pro bikes Ridstar does list are the Q20 Pro and the Q30 Pro, and our reviews of them print the figures Ridstar gives.

What is the Ridstar Q50 Lite?

A separate bike. Ridstar lists it at 1000 W as "Ridstar® Q50/Q30Lite 1000W 15.6AH Fat Tire Electric Bike" for $599 on ridstar.net and as "Q50 Lite 1000W 48V 15AH" for $1,079.00 on ridstar.com with the US market selected, both in stock on October 16, 2026. This review covers the 25AH Q50 only. Our store sells the Q50 Lite as the Q30 Lite, and our Ridstar Q30 Lite review covers it.

Which Ridstar website should you buy the Q50 from?

Ridstar's ridstar.net banner reads "The only official website of ridstar", its statement calls other sites "our dealers", and ridstar.com says its warranty is "only available to customers ordering from ridstar.com". On October 14, 2026 the 25AH bike cost $759 on ridstar.net, $1,389 on ridstar.com and $918.85 here. Service for a bike bought elsewhere is Ridstar's to state, and for a bike bought here buying it from us states ours.

Does the Ridstar Q50 have a throttle?

Ridstar's listing says "Twist Grip Throttle" and names three riding modes, "pure electric, electric assist, and pedal", and its parts store sells a "Turning Handle Throttle" in a "US / Q50" variant at $59, in stock on October 14, 2026. The range tables treat the ride with no pedaling as the throttle ride, so every figure here that says no pedaling is the throttle's.

How tall do you need to be for the Ridstar Q50?

Ridstar's pages print a window of 5'4" to 6'2". If you are 5'10" with the Army survey's median inseam of 33.8 inches, the saddle formula sets the saddle top 36.8 inches above the pedal axle, and the saddle table gives the figure for each height from 5'0" to 6'4".

Can you replace the Ridstar Q50's battery?

Ridstar sells one. Its parts store lists a "US / Q50 25AH" variant at $379, in stock on October 14, 2026, under a product titled "Ridstar Q20/DC26/H20 48V 20AH 15AH Removable Electric E-Bike Battery", and that is 41% of our price for the whole bike. Ask which pack you would receive before you buy one.

Is the Ridstar Q50 worth it?

At $918.85 it gives 1,200 Wh, about 77 cents per watt-hour, against 109 cents for our Q20. It is worth it if you ride where a 2,000 W machine is allowed and you have weighed the maker's record; if not, the verdict names the bikes to read instead.

Limitations of this review

Each item below is a limit on what this page can tell you about the Q50, and what that limit means for your own decision.

1. Ridstar's figures disagree, and each is printed. The motor is 2,000 W in the spec block and 1,500 W in the description; the top speed is 28+++ mph in the text, 28 mph on ridstar.com's slider and 25 mph on the panel; the torque is 85 N·m in the text and 80 on the panel; and the slope is 30° on ridstar.net and 35° on ridstar.com.
2. The bike's weight is not published. The model brackets it with the printed weights of two other Ridstar bikes, 92.6 and 66 lb, and the difference moves the 15 mph range by about two miles.
3. The motor in the range model is a comparable whose curve is not the Q50's own. Bafang's published curve is rebuilt at 48 V and 2,000 W with its no-load speed set from Ridstar's 28 mph, and the sensitivity cases move the 15 mph figure from 64 to as much as 74 miles.
4. The tire's outer diameter is borrowed. Ridstar prints a "20 inch" wheel and a 20 × 4.0 tire, and the model uses Samebike's printed 22.8 inches for the same tire; it sets the torque a climb needs and does not change the flat-road figures.
5. No ride of a Q50 to an empty pack is used. The model's miles are checked against published physics and the maker's own figures, so every range figure here is computed.
6. The Q50's tires were not measured. Ridstar names no tire maker, so the bracket covers the ten fat tires the drum recorded.
7. The cold table uses LG HG2 cell data, and Ridstar names no cell for the Q50; the brackets widen below freezing.
8. The speed behind each of Ridstar's six range figures is not printed, so the maker's band shows the rides they would take.
9. Ridstar publishes no geometry for the Q50. The standover, the cockpit lean and the hand load are not computed, and the saddle figures are the formula's, with no seat-post range to check them against.
10. The fit tables use the US Army's ANSUR II survey, 4,082 men and 1,986 women, a population different from the general public. Your own inseam outranks any row.
11. The saddle formulas are averages. Published recommendations run from 106% to 110.4% of inseam, and the heel check is the test on your own leg.
12. Ridstar's pages carry no UL certificate to read. None of the three Q50 listings or their 18 images prints a UL standard, a certificate holder or a file number.
13. The warnings, the UK report and the suits do not name the Q50, and nothing published says whether it shares the warned bikes' parts; this review does not say either way.
14. No Q50 manual is linked. The page titled "Ridstar/YVY User Manual" on ridstar.com holds a returns policy and links no manual, and the same address on ridstar.net answered 404 on October 14, 2026, so the torque, tire pressure and charger figures a manual might give are unknown here.
15. The one r/ebike thread that names the Q50 is a buyer's question about Ridstar's two stores; its replies are opinions, one of them about the Q20, and none is quoted as evidence about the bike.
16. The store comparison covers ridstar.net and ridstar.com. Other sites that carry the Ridstar name were checked for a Q50 on October 14, 2026: ridstar.eu lists none, ridstar.uk answered 404 on every route and ridstar-ebike.com answered every request with a captcha, so those two could not be read.
17. The state census is a reading of statutes as published on September 24, 2026. A change after that date is outside it; our atlas carries each state's current definition.
18. Our own listing's text predates parts of this page. On October 14, 2026 our checkout offered a credit card and Google Pay, ridstar.com's US price for the 25 Ah bike was $1,389, and both Ridstar stores printed a rider window; where our listing's older text differs, this review follows those reads.

The bottom line

Buy the Ridstar Q50 if you want one 1,200 Wh pack on a moped-style fat-tire bike for $918.85, you are 5'4" to 6'2", and you ride where your state's rules take a motor Ridstar prints at 2,000 W and at 1,500 W.

On flat pavement it computes to 64 miles at 15 mph with no pedaling for a 180 lb rider, 48 with a quarter kept in reserve, and charging for 1,000 such miles a year costs about $3.42 a year.

Read the maker's record and our warranty answer before you order, and ask us anything they leave open. If you ride bike lanes or paths, the VTUVIA SF20H is the bike with a printed 750 W motor; if you want the same kind of machine from a maker no notice names, the Samebike M20 is $999.

Image credit: every image below the cover is Ridstar's own photograph of the Q50 from its ridstar.net gallery: the studio view and the headlight-and-tail-light close-up scaled uniformly, five crops of the studio view that change no pixel, and the fork-and-shock close-up as Ridstar published it; none is retouched.

Cover: Ridstar's own front three-quarter studio photograph of the Q50, scaled uniformly with no pixel of the bike changed; the studio around it was generated on Playcut (playcut.ai) with Nano Banana Pro, and the type and its shading are laid on top.

Source register

Each source behind this review is listed below with the tier we grade it at, the claim it supports and the date we read it, so you can open any of them and check the figure yourself.

Expiry conditions

Any of these would date the page: a recall, a new warning or a change to either warning from the CPSC; a new figure, a changed listing or a manual on any Ridstar store; or a ruling or a new filing in either lawsuit.

So would a change to our listing's price, stock or text, or to our shipping or refund policy; a change to 15 U.S.C. § 2085 or to California Vehicle Code §§ 312.5, 406 or 21207.5; or a change to any state definition in our census. Verified October 14, 2026.

References

Each document cited on this page is listed with its publisher, its title, the part relied on and the date it was retrieved, so you can check any figure at its source.

1. U.S. Consumer Product Safety Commission, CPSC Warns Consumers to Immediately Stop Using Ridstar E-Bikes Due to Fire Hazard; Risk of Serious Injury or Death. CPSC warning 26-337, March 19, 2026: names the Ridstar Q20 and Q20 Pro (not the Q50); battery and wiring fire hazard; 11 reports of fire; the manufacturer 'has refused to agree to an acceptable recall'; the e-bikes are black, the brand name Ridstar is printed on the battery, and the model number is on the purchase receipt. Retrieved Oct 14, 2026. https://www.cpsc.gov/Warnings/2026/CPSC-Warns-Consumers-to-Immediately-Stop-Using-Ridstar-E-Bikes-Due-to-Fire-Hazard-Risk-of-Serious-Injury-or-Death
2. U.S. Consumer Product Safety Commission, CPSC Warns Consumers to Stop Using Ridstar E-Bikes Immediately Due to Crash Hazard; Risk of Serious Injury or Death. CPSC warning 26-584, June 25, 2026: names the Ridstar Q20 and Q20 Lite (not the Q50); front wheel detachment; 32 reports; the manufacturer 'has been unresponsive'; the e-bikes are black, the brand name Ridstar is printed on the battery, and the model number is on the purchase receipt. Retrieved Oct 14, 2026. https://www.cpsc.gov/Warnings/2026/CPSC-Warns-Consumers-to-Stop-Using-Ridstar-E-Bikes-Immediately-Due-to-Crash-Hazard-Risk-of-Serious-Injury-or-Death
3. U.S. Consumer Product Safety Commission, Product safety warning listing (CSV). CPSC product safety warning listing (CSV): 375 rows, both Ridstar warnings listed, no other Ridstar row. Retrieved Oct 14, 2026. https://www.cpsc.gov/s3fs-public/recall-data/product_safety_warning_listing.csv
4. U.S. Consumer Product Safety Commission, Recalls & Product Safety Warnings. CPSC recalls: no Ridstar recall in the whole list (10,047 records to October 8, 2026) or the recall feed (40 items), no record naming a Q50, with controls. Retrieved Oct 14, 2026. https://www.cpsc.gov/Recalls
5. Office for Product Safety and Standards (UK), Product Safety Report: Ridstar E-Bikes and Chargers (2506-0011). UK OPSS product safety report 2506-0011, June 19, 2025: Q20-Plus, Q20-Mini, E26 Pro and chargers; serious fire risk; import rejected; not the Q50. Retrieved Oct 14, 2026. https://www.gov.uk/product-safety-alerts-reports-recalls/product-safety-report-ridstar-e-bikes-and-chargers-2506-0011
6. U.S. District Court for the District of Oregon (docket via CourtListener RECAP), Cunanan v. Amazon.com Services LLC, No. 3:26-cv-00692. Cunanan v. Amazon.com Services LLC, No. 3:26-cv-00692 (D. Or.): allegations about a Ridstar Q20; undecided on its docket. Retrieved Oct 14, 2026. https://www.courtlistener.com/docket/73159439/cunanan-v-amazoncom-services-llc/
7. U.S. District Court for the Southern District of Florida (docket via CourtListener RECAP), L.E., a minor, v. Walmart Inc., No. 9:26-cv-81045. L.E. v. Walmart Inc., No. 9:26-cv-81045 (S.D. Fla.): allegations about a Ridstar bike sold on Walmart.com; undecided on its docket. Retrieved Oct 14, 2026. https://www.courtlistener.com/docket/74691512/le-v-walmart-inc/
8. US Government Publishing Office, 15 U.S.C. § 2085 — Low-speed electric bicycles. 15 U.S.C. § 2085(b): the federal low-speed electric bicycle definition (under 750 W; under 20 mph). Retrieved Oct 12, 2026. https://www.govinfo.gov/content/pkg/USCODE-2024-title15/html/USCODE-2024-title15-chap47-sec2085.htm
9. California Legislative Information, California Vehicle Code § 312.5. Cal. Veh. Code § 312.5(a): the California electric bicycle definition ('does not exceed 750 watts of power'); class 2 limit of 20 mph. Retrieved Oct 12, 2026. https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=VEH&sectionNum=312.5.
10. California Legislative Information, California Vehicle Code § 406. Cal. Veh. Code § 406(a): motorized bicycle or moped (under 4 gross brake horsepower; not more than 30 mph on level ground). Retrieved Oct 12, 2026. https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=VEH&sectionNum=406.
11. California Legislative Information, California Vehicle Code § 21207.5. Cal. Veh. Code § 21207.5(a): motorized bicycles on bicycle paths and trails, and the exception for roadways. Retrieved Oct 12, 2026. https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=VEH&sectionNum=21207.5.
12. Forest Service, USDA (eCFR), 36 CFR § 261.13 — Motor vehicle use. 36 CFR 261.13: the National Forest motor vehicle use map rule. Retrieved Sep 26, 2026. https://www.ecfr.gov/current/title-36/chapter-II/subchapter-B/part-261/subpart-A/section-261.13
13. U.S. Department of Agriculture, Forest Service (Office of the Federal Register, eCFR), 36 CFR 261.2 Definitions. 36 CFR 261.2: the definition of motor vehicle (any self-propelled vehicle). Retrieved Sep 26, 2026. https://www.ecfr.gov/current/title-36/chapter-II/part-261/subpart-A/section-261.2
14. U.S. Department of Agriculture, Forest Service (Office of the Federal Register, eCFR), 36 CFR 261.1b Penalty. 36 CFR 261.1b: the penalty for a breach of Part 261. Retrieved Sep 26, 2026. https://www.ecfr.gov/current/title-36/chapter-II/part-261/subpart-A/section-261.1b
15. U.S. Army Natick Soldier Research, Development and Engineering Center, 2012 Anthropometric Survey of U.S. Army Personnel (ANSUR II), public data release 2017. ANSUR II, public release: the rider bodies (6,068) the fit model's saddle table is built on. Retrieved Sep 25, 2026. https://www.army.mil/article/188601/for_good_measure_natick_releases_raw_data_from_army_wide_anthropometric_survey
16. NOAA, NASA, US Air Force, U.S. Standard Atmosphere, 1976 (NOAA-S/T 76-1562; NASA TM-X-74335). U.S. Standard Atmosphere 1976: the air density used by the range model. Retrieved Sep 23, 2026. https://ntrs.nasa.gov/api/citations/19770009539/downloads/19770009539.pdf
17. BAFANG, BAFANG Workbook OEM 2021. Bafang OEM workbook 2021: the comparable motor curve (rated voltage, no-load speed, efficiency floor, maximum torque). Retrieved Sep 23, 2026. https://www.bafang-e.com/Uploaded/Labels/BAFANG%20Workbook%20OEM%202021.pdf
18. Bicycle Rolling Resistance (Jarno Bierman), Fat Bike Tires Test Results. Bicycle Rolling Resistance: ten fat-tire rolling-resistance tests on a drum (median, lowest and highest). Retrieved Sep 25, 2026. https://www.bicyclerollingresistance.com/fat-bike-reviews
19. Journal of Applied Biomechanics (Human Kinetics), Martin JC, Milliken DL, Cobb JE, McFadden KL, Coggan AR. Validation of a Mathematical Model for Road Cycling Power. Martin et al. (1998): the cycling-power model, its Appendix I values, and the chain efficiency. Retrieved Sep 23, 2026. https://collections.lib.utah.edu/dl_files/b4/8e/b48ef26086091662c561e673d7bd990d77868437.pdf
20. Journal of Sports Sciences (Taylor & Francis), Tengattini S, Bigazzi AY. Physical characteristics and resistance parameters of typical urban cyclists. Tengattini & Bigazzi (2018): frontal area and drag for upright cruisers and mountain bicycles. Retrieved Sep 23, 2026. https://civil-reactlab.sites.olt.ubc.ca/files/2022/11/Tengattini_2018_Physical-characteristics-and-resistance-parameters-of-typical-urban-cyclists.pdf
21. World Electric Vehicle Journal (MDPI), Arango I, Lopez C, Ceren A. Improving the Autonomy of a Mid-Drive Motor Electric Bicycle Based on System Efficiency Maps and Its Performance. Arango, Lopez & Ceren (2021): battery efficiency as a function of current. Retrieved Sep 23, 2026. https://mdpi-res.com/d_attachment/wevj/wevj-12-00059/article_deploy/wevj-12-00059.pdf
22. IEEE / EPE'19 ECCE Europe (Karlsruhe Institute of Technology authors), Schmitt M, Decker S, Doppelbauer M. Measuring and Characterization of a Pedal Electric Cycle (Pedelec) on a Full System Test-Bench. Schmitt, Decker & Doppelbauer (2019): a measured pedelec used 75% of its nominal pack. Retrieved Sep 23, 2026. https://publikationen.bibliothek.kit.edu/1000100371/50695920
23. McMaster University (Kollmeyer et al.), Mendeley Data, LG 18650HG2 Li-ion Battery Data and Example Deep Neural Network xEV SOC Estimator Script. LG 18650HG2 cell data (McMaster, Kollmeyer): cell energy relative to 25 °C at low temperature. Retrieved Sep 23, 2026. https://doi.org/10.17632/b5mj79w5w9.2
24. Journal of Exercise Physiology Online (American Society of Exercise Physiologists), Peveler et al., Comparing methods for setting saddle height in trained cyclists, JEPonline 8(1):51-55. Peveler et al. (2005): saddle-height methods compared, the 109% formula and the heel method. Retrieved Sep 25, 2026. https://www.asep.org/asep/asep/JEPonlineFEBRUARY2005_PevelerSaddle.doc
25. Journal of Strength and Conditioning Research (NSCA), Ferrer-Roca V, Roig A, Galilea P, Garcia-Lopez J. Influence of saddle height on lower limb kinematics in well-trained cyclists: static vs. dynamic evaluation in bike fitting. J Strength Cond Res 26(11):3025-9; doi 10.1519/JSC.0b013e318245c09d. Ferrer-Roca et al. (2012): the saddle-height ranges and the knee-angle band used for the 25 to 35 degree target. Retrieved Sep 25, 2026. https://pubmed.ncbi.nlm.nih.gov/22190163/
26. Journal of Strength and Conditioning Research (NSCA), Peveler, Pounders & Bishop, Effects of saddle height on anaerobic power production in cycling, JSCR 21(4):1023-7. Peveler, Pounders & Bishop (2007): saddle height and knee range in trained cyclists. Retrieved Sep 25, 2026. https://pubmed.ncbi.nlm.nih.gov/18076230/
27. University of Colorado Boulder (MS thesis), Carahalios A. An Analysis of the Bicycle-Rider Interface Forces in Stationary Road Cycling (MS thesis, Department of Integrative Physiology, University of Colorado). Carahalios (2015): hand load on the stem, about 15% of body weight, ten road racers on the hoods. Retrieved Sep 25, 2026. https://scholar.colorado.edu/downloads/70795789x
28. UL Solutions, E-Bikes Certification: Evaluating and Testing to UL 2849. UL Solutions: e-bike certification to UL 2849, which covers the drive train, battery and charger as one system. Retrieved Sep 26, 2026. https://www.ul.com/services/e-bikes-certificationevaluating-and-testing-ul-2849
29. YVY / HK Ridstar Trade Limited (yvyebike.com), Company Address. YVY company address: the business is HK Ridstar Trade Limited. Retrieved Oct 12, 2026. https://yvyebike.com/pages/company-address
30. Ridstar (ridstar.net), Ridstar Official Statement. Ridstar Official Statement (ridstar.net): 'Except for customers who purchase from ridstar.net, we will not provide any after-sales service to customers who purchase ridstar products from other places.'; 'Except ridstar.net, other similar websites are our dealers'; header 'The only official website of ridstar'. Retrieved Oct 14, 2026. https://ridstar.net/pages/ridstar-official-statement
31. Ridstar (ridstar.net), Ridstar® Q50 2000W 25AH Fat Tire Electric Bike — ridstar.net product page (variant 'US', $759). Ridstar's Q50 25AH listing: one motor rated 2,000 W in the spec block and 1,500 W in the description; 85 N·m; 28+++ mph; 30°; one removable 48V 25Ah pack; six range figures; three riding modes; a twist-grip throttle; Shimano 7-speed; hydraulic brakes; 330 lb; a rider window; 4-6 hours; a one-year warranty. Retrieved Oct 14, 2026. https://ridstar.net/products/ridstar%C2%AE-q50-2000w-fat-tire-electric-bike
32. Ridstar (ridstar.net), Ridstar® Q50/Q30 2000W 20AH Fat Tire Electric Bike — ridstar.net product page (variant 'US', $699). The same Q50 listed on ridstar.net as 'Q50/Q30' 20AH at $699, in stock; text identical to the 25AH listing except its pack and range figures. Retrieved Oct 14, 2026. https://ridstar.net/products/ridstar%C2%AE-q50-2000w-20ah-fat-tire-electric-bike
33. Ridstar (ridstar.com), Ridstar Q50 2000W 48V 20AH 25AH Fat Tire Electric Bike — ridstar.com product page. Ridstar's ridstar.com Q50 listing (US market): variants 48V 20Ah $1,279 and 48V 25Ah $1,389, in stock; a 28 MPH slider; '25-28mph'; '35-degree roads'; a rider window; a two-year warranty available only to customers ordering from ridstar.com. Retrieved Oct 14, 2026. https://ridstar.com/products/ridstar-q50-2000w-48v-20ah-fat-tire-electric-bike
34. Ridstar (ridstar.net), Ridstar® Q50/Q30Lite 1000W 15.6AH Fat Tire Electric Bike — ridstar.net product page. Ridstar's separate Q50 Lite on ridstar.net: 1000 W, 15.6AH, $599, in stock. Retrieved Oct 16, 2026. https://ridstar.net/products/ridstar%C2%AE-q50lite-1000w-15-6ah-fat-tire-electric-bike
35. Ridstar (ridstar.com), Ridstar Q50 Lite 1000W 48V 15AH Electric Bike — ridstar.com product page. Ridstar's separate Q50 Lite on ridstar.com (US market): $1,079.00, in stock. Retrieved Oct 16, 2026. https://ridstar.com/products/ridstar-q50-lite-1000w-48v-15ah-electric-bike
36. Ridstar (ridstar.net gallery), Ridstar Q50 25AH gallery image 2 (battery panel). Ridstar's Q50 gallery image 2 (battery panel): 'REMOVABLE BATTERY', '90Miles Max Range', 'Lockable', 'Fast Charging', 'BMS Power Saving', '48V 25AH'. Retrieved Oct 14, 2026. https://cdn.shopify.com/s/files/1/0696/9960/0602/files/20260625114848_6535_26.jpg?v=1782359375
37. Ridstar (ridstar.net gallery), Ridstar Q50 25AH gallery image 3 (motor panel). Ridstar's Q50 gallery image 3 (motor panel): '2000W BRUSHLESS MOTOR'; stat bar '25mph Top Speed', '80n.m Max Torque', 'SHIMANO 7 Speed Gears', '30° Slope'. Retrieved Oct 14, 2026. https://cdn.shopify.com/s/files/1/0696/9960/0602/files/fc5dc0e2e86730ccfe54bc1011ba996e.jpg?v=1782360106
38. Ridstar (ridstar.net parts store), Ridstar Turning Handle Throttle (two keys included). Ridstar sells a 'Turning Handle Throttle (two keys included)' for the Q50: variant 'US / Q50', $59, in stock. Retrieved Oct 14, 2026. https://ridstar.net/products/ridstar-turning-handle-throttle-two-keys-included
39. Ridstar (ridstar.net parts store), Ridstar Q20/DC26/H20 48V 20AH 15AH Removable Electric E-Bike Battery. Ridstar sells a replacement pack for the Q50, variant 'US / Q50 25AH', $379, in stock, under a product titled '...48V 20AH 15AH Removable Electric E-Bike Battery'. Retrieved Oct 14, 2026. https://ridstar.net/products/ridstar-q20-dc26-h20-48v-20ah-removable-electric-e-bike-battery
40. Ridstar (ridstar.net parts store), Ridstar Motor (Please provide the motor code). Ridstar sells a Q50 motor ('Ridstar Motor', variant 'US / Q50', $209), in stock. Retrieved Oct 14, 2026. https://ridstar.net/products/ridstar-motor
41. Ridstar (ridstar.net parts store), Ridstar Controller. Ridstar sells a Q50 controller ('Ridstar Controller', variant 'US / Q50', $89), in stock. Retrieved Oct 14, 2026. https://ridstar.net/products/ridstar-controller
42. Ridstar (ridstar.net parts store), Ridstar Front fork. Ridstar sells a Q50 front fork ('Ridstar Front fork', variant 'US / Q50', $189), in stock. Retrieved Oct 14, 2026. https://ridstar.net/products/ridstar-front-fork
43. Ridstar (ridstar.net parts store), Ridstar Electric bikes brake set. Ridstar sells Q50 brake sets ('Ridstar Electric bikes brake set', variants 'US / Left front brake / Q50' and 'US / Right rear brake / Q50', $90 each), in stock. Retrieved Oct 14, 2026. https://ridstar.net/products/rear-brake-set
44. Ridstar (ridstar.net), Company Address — ridstar.net. Ridstar's company page names its business as HK RIDSTAR TRADE LIMITED, Hung Hom, Kowloon. Retrieved Oct 14, 2026. https://ridstar.net/pages/company-address
45. Internet Archive (Wayback Machine), Wayback Machine capture of ridstar.net's Q50 25AH listing, August 30, 2026. Ridstar's Q50 25AH listing as captured on August 30, 2026: $799, in stock, with the same range, motor and rider-window lines. Retrieved Oct 14, 2026. https://web.archive.org/web/20260830203036/https://ridstar.net/products/ridstar%C2%AE-q50-2000w-fat-tire-electric-bike
46. Redtail eBikes (our listing), Ridstar Q50 2000W 48V 25Ah Fat Tire Electric Bike — our product page. Our Q50 listing: $918.85, one variant, buyable (inventory not tracked); parts of its body text predate this page's reads of October 14, 2026. Retrieved Oct 14, 2026. https://redtailebikes.com/products/ridstar-q50-2000w-fat-tire-electric-bike
47. Redtail eBikes (our listing), Ridstar Upgraded Q20 1500W Fat Tire Electric Bicycle — our product page. Our Q20 listing: the 20AH variant $1,045.35, in stock (the 25AH variant on the same listing was not buyable). Retrieved Oct 14, 2026. https://redtailebikes.com/products/ridstar-upgraded-q20-1500w-fat-tire-electric-bicycle
48. Redtail eBikes, Shipping policy. Our shipping terms: free shipping on every electric bike within the contiguous United States; Alaska, Hawaii, U.S. territories, P.O. boxes and remote areas may incur additional charges or be excluded. Retrieved Oct 14, 2026. https://redtailebikes.com/policies/shipping-policy
49. Redtail eBikes, Refund policy. Our refund terms: change-of-mind returns only unopened and factory-sealed, within 72 hours of delivery, 15% restocking fee and return freight; damage claims within 48 hours with photos, we file the carrier claim; power, charging and component faults 'covered under manufacturer warranty', we coordinate the repair or replacement; a 3% transaction fee on cancellations. Retrieved Oct 14, 2026. https://redtailebikes.com/policies/refund-policy
50. U.S. Energy Information Administration, Electric Power Monthly, Table 5.6.A. Average Price of Electricity to Ultimate Customers by End-Use Sector. Average US residential electricity price, July 2026: 18.31 cents per kWh. Retrieved Oct 14, 2026. https://www.eia.gov/electricity/monthly/epm_table_grapher.php?t=epmt_5_06_a
51. VTUVIA (maker), VTUVIA SF20H Utility Ebike — maker product page. VTUVIA's figures for the SF20H: '750W Motor Power'; 'UL2271 & UL2849 Safety Certified'; 'Speed Class 2'; a 672 Wh pack; a 60 lb net weight including rear racks and fenders; White and Black in stock on its US store. Retrieved Oct 14, 2026. https://vtuviaebike.com/products/sf20h-fat-tire-folding-electric-bike-ul-certified-ebike
52. Samebike (maker), M20 Off Road Peak 1800W Fat Tire Electric Bike — Samebike US product page. Samebike's figures for the M20: '1800W Peak Motor'; '48V 18Ah'; the description's 'M20 1200W Electric Bike'; Peru in stock on its US store, the other three colors sold out. Retrieved Oct 14, 2026. https://us.samebike.com/products/m20-off-road-peak-1800w-fat-tire-electric-bike
53. Samebike (maker), M20-III Off Road Peak 3000W Fat Tire Electric Bike — Samebike US product page. Samebike's printed wheel figure for the same 20 x 4.0 tire, 22.8 inches, the range model's wheel comparable. Retrieved Oct 2, 2026. https://us.samebike.com/products/m20-iii-off-road-peak-3000w-fat-tire-electric-bike
54. Reddit, r/ebike (a shopper), Ridstar websites. A first-time buyer's question on r/ebike, August 9, 2026: the same Q50 was '$1.4K' on ridstar.com and '6 hundred dollars less' on ridstar.net. Retrieved Oct 14, 2026. https://www.reddit.com/r/ebike/comments/1vk585l/ridstar_websites/
55. State of Rhode Island General Assembly, R.I. Gen. Laws § 31-1-3 (definitions). Rhode Island's electric bicycle definition: a motor 'rated not more than two (2) (S.A.E.) horsepower', about 1,491 W. Retrieved Sep 24, 2026. https://webserver.rilegislature.gov/Statutes/TITLE31/31-1/31-1-3.HTM
56. District of Columbia (DC Council), DC Code § 50-2201.02. The District's motorized bicycle definition: 'A motor incapable of propelling the device at a speed of more than 20 miles per hour'; no motor-watt limb. Retrieved Sep 24, 2026. https://code.dccouncil.gov/us/dc/council/code/sections/50-2201.02
57. Oregon Legislature, ORS chapter 801 (ORS 801.258). Oregon's electric assisted bicycle definition (ORS 801.258): classes by speed, no motor-watt limb since HB 4103 (2024). Retrieved Sep 24, 2026. https://www.oregonlegislature.gov/bills_laws/ors/ors801.html
58. Redtail eBikes (our state census), Our census of state e-bike definitions, 51 rows (50 states and DC). Our census of the 51 state e-bike definitions, read September 24, 2026: 44 set a 750-watt motor limb; Rhode Island 2 SAE hp; the District, Montana, New Jersey and Oregon no power figure; Alaska and Kentucky no e-bike definition. Retrieved Sep 24, 2026. https://redtailebikes.com/blogs/journal/electric-bike-laws
59. Ridstar (ridstar.net), Ridstar® Q30 Luxe 2000W Fat Tire Ebike — ridstar.net product page. Ridstar's Q30 Luxe record: 'Actual weight: 42kg' beside 'Motor parameters: 48v2000W', 'Tire size: 20*4.0', 'Capacity 20AH' and 'Battery *1'; the weight bracket's heavier end, 92.6 lb. Retrieved Oct 12, 2026. https://ridstar.net/products/ridstar%C2%AE-q30luxe-2000w-fat-tire-ebike
60. Ridstar (ridstar.com), Ridstar Q20 1500W Fat Tire Ebike — ridstar.com product page. Ridstar's Q20 1500W record on ridstar.com: 'Item Weight' 66 Pounds; '1500W'; '48V 20AH'; the weight bracket's lighter end, and the comparison table's Q20 column. Retrieved Oct 12, 2026. https://ridstar.com/products/ridstar-q20-1500w-fat-tire-ebike
61. Ridstar (ridstar.com), Ridstar/YVY User Manual — ridstar.com page. Ridstar's page titled 'Ridstar/YVY User Manual' on ridstar.com holds a returns policy and links no manual; the same address on ridstar.net answered 404 on October 14, 2026. Retrieved Oct 14, 2026. https://ridstar.com/pages/ridstar-yvy-user-manual
62. Ridstar (ridstar.eu), ridstar.eu product sitemap. Ridstar.eu lists no Q50: its 538 KB product sitemap lists Q20 pages and none for a Q50, with the Q20 controls read. Retrieved Oct 14, 2026. https://ridstar.eu/product-sitemap.xml
63. Ridstar (ridstar.net), ridstar.net and ridstar.com product catalogs (products.json, page 1). Ridstar's two stores' product counts on October 14, 2026: 85 titles on ridstar.net, 55 on ridstar.com, none a 'Q50 Pro'. Retrieved Oct 14, 2026. https://ridstar.net/products.json
64. Ridstar (ridstar.com), ridstar.com product catalog (products.json, page 1). Ridstar.com's product count on October 14, 2026: 55 titles, none a 'Q50 Pro'; its Q50 family is 'Ridstar Q50 Lite 1000W 48V 15AH Electric Bike' and 'Ridstar Q50 2000W 48V 20AH 25AH Fat Tire Electric Bike'. Retrieved Oct 14, 2026. https://ridstar.com/products.json
65. Playcut, Playcut. Tool credit: Playcut, where the studio around Ridstar's studio photograph of the Q50 on the cover was generated with Nano Banana Pro (the studio of another of our reviews, reused), credited with a backlink; not a source of any fact. Retrieved Oct 14, 2026. https://playcut.ai