VTUVIA CMB 8-Speed Review 2026: 175 N·m for $1,399

$1,399 · a 500 W mid-drive motor at the cranks, 820 W peak in VTUVIA's table, 175 N·m · a 48 V 14.4 Ah LG pack of 691.2 Wh · Class 2 as delivered, 20 mph · Shimano 8-speed, Logan hydraulic brakes on 160 mm rotors · 26 × 2.4 tires · 60 lb, 300 lb total capacity · Metallic Silver or Dark blue · verified October 2, 2026

Quick Answer — The CMB 8-Speed is VTUVIA's $1,399 step-through city bike with its motor at the cranks: 500 W rated, 175 N·m, a 691.2 Wh LG pack, eight Shimano gears and a 16.9-inch step. With 180 lb aboard at a steady 15 mph on the throttle over flat ground, a full pack computes to about 44 miles.

Pedal easily at that 15 mph and the charge stretches to about 74 miles; hold 20 mph on the throttle and it shrinks to about 29. VTUVIA's product page lists 80 miles on pedal assist and 45 on the throttle, and the range section turns both into rides you can plan.

Because the motor pulls through the chain, the gear you pick changes what the pack spends: up a 4% grade at 15 mph, the model's motor uses 57.2 Wh a mile with the chainring at 50 rpm and 43.0 Wh at 90 rpm. It ships as a Class 2 bike, pedal assist and a thumb throttle to 20 mph.

What this review covers

Specification · What it is · Fit · Motor · Battery · Range · Brakes and controls · Fork and gears · Weight and load · The Mercer fit test · UL certification · Recalls · Class · Federal land · Green and red flags · Verdict · Checklist · Buying from us · FAQ · Limitations · Bottom line · References

How we verified this CMB 8-Speed review

Each figure was read on October 2, 2026, or on September 28 where a line says so, from VTUVIA's CMB product page, its product record, VTUVIA's CMB PRO size chart, its CMB posts, our own listing and the statutes quoted in the class section. The range and fit sections are computed, and each prints its formula and inputs; the range section also sets its figures beside a measured ride on the CMB's 10-speed sibling.

This is a specification-verified review: every number traces to VTUVIA, a statute, published research or arithmetic printed on this page. We sell the CMB, so give the red flags the same attention as the green.

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

The CMB 8-Speed on paper: VTUVIA's specification

These are VTUVIA's own words and figures as the CMB page and its record printed them, read September 28 and October 2, 2026, with the second figures from the VTUVIA posts named in the references. The pack's 691.2 Wh is 48 volts multiplied by 14.4 amp-hours.

Seven of the CMB's specifications appear more than one way. Across its page, record, size chart and posts, VTUVIA prints the peak power, the pack, the fork, the tire width, the bell, the capacity and the lowest seat in different forms; each appears on this page where it matters, and the range and fit models plan on the specification table's figures.

A mid-drive city bike for $1,399

The CMB puts its motor where the pedals turn. VTUVIA's page heads it "Mid-Drive Commuter Ebike", so the motor drives the chainring and its power reaches the rear wheel through the same eight Shimano gears your legs use. The frame steps through at 16.9 inches, and the rack, fenders and lights arrive fitted.

A helmeted rider with a dark-blue CMB on a forest road, in a photograph from VTUVIA's CMB page.

The CMB name has covered three builds. VTUVIA's July 2024 launch post describes a CMB PRO "available with a single-speed belt drive", and its September 2024 post gives that belt bike a 720 Wh pack. A 10-speed chain version followed in October 2024, the bike Scott Hardesty rode.

The bike on this page is the 8-speed chain build with Logan brakes that VTUVIA sells as the CMB 8-Speed; its class note on the same page still calls it the CMB PRO. Where a reviewer's ride below comes from an earlier build, the sentence says so.

On our shelf the CMB's nearest sibling is the Zeal LT7, a VTUVIA step-through with its motor in the rear hub instead. The rows below are what separate them, $300 apart.

The CMB rows from VTUVIA's CMB page and the LT7 rows from our Zeal LT7 review, with both of our listings read October 2, 2026.

The two torque figures sit on different shafts, the CMB's at the cranks before the gears and the LT7's at the wheel, so the climbing tables say more than the torque row. With 180 lb aboard on a 10% grade, the CMB's motor alone holds about 11.2 mph by this page's model, against about 8.6 mph for the LT7 in its review.

So the CMB is a 26-inch step-through for hilly city streets, with the motor at the cranks, a 691.2 Wh pack and eight gears, for $1,399.

Will the VTUVIA CMB 8-Speed fit you? Saddle, stop and reach

VTUVIA sizes the CMB for riders from 5'1" to 6'1", with a 27- to 33-inch inseam. For a median 5'1" rider in the US Army's ANSUR II survey, the saddle formula sets the saddle's top 31.8 inches above the pedal axle; for a median 6'1" rider, 38.8 inches.

The distance runs from the center of the lower pedal's axle, with the crank pointed down along the seat tube, to the top of the saddle, so you can check it with a tape measure. The tables set 6,068 measured soldiers, women and men, against the formula at every height from 5'1" to 6'1".

VTUVIA prints one window for the CMB, 5'1" to 6'1", on its product page and again on its CMB PRO size chart.

Find your own number in three steps:

1. Measure your inseam in socks. Stand with your back against a wall, draw a hardcover book up between your legs until it stops, spine level, and have someone measure from the floor to the spine.
2. Look up your height in the saddle table, and set your inseam beside VTUVIA's 27 to 33 inches.
3. Set the saddle from your row when the bike arrives, then adjust it with the knee and heel checks.

How high should my saddle go?

For the median 5'1" rider the formula wants 31.8 inches from pedal axle to saddle top; for the median 6'1" rider, 38.8 inches. Every figure is 109% of the median inseam at that height, the multiple evaluated in Peveler et al., 2005, and the two right-hand columns show where the 106% to 110.4% band of Ferrer-Roca et al., 2012 would set it.

Pedal axle to saddle top for the median rider at each height, at 109% of inseam and at both ends of the published band; the inseam column runs from the survey's 5th to its 95th percentile, women and men together.

From 5'9" up, measure your inseam before you order. At 5'9" the survey's median inseam is 33.1 inches, just past VTUVIA's recommended 33, and it rises to 34.3 inches at 5'11" and 35.6 at 6'1", the top of VTUVIA's height window.

The seat itself goes from 31.5 inches above the floor at its lowest to 39.4 at its highest, by VTUVIA's figures. A height above the floor becomes a pedal-axle distance only with the crank's length and its axle height (Limitations), so if you are tall, read your inseam against the red flags first.

Can I put my feet down at a stop?

Standing over the frame, with room to spare: at 5'1", 95 of every 100 riders clear VTUVIA's 16.9-inch step by 10.8 inches or more, and at 6'1" by 17.0 inches or more. Sitting on the saddle at its lowest is a separate matter, which the second table answers from VTUVIA's lowest seat.

Each survey body's barefoot inseam minus VTUVIA's 16.9-inch "Standover height"; the middle column is the median inseam, and the last is the clearance that 95 of every 100 riders at that height meet or beat.

On the saddle at its lowest, most riders from 5'6" up sit with both feet flat, and most from 5'5" down do not. VTUVIA's lowest seat is 31.5 inches up, so the median 5'5" rider's barefoot inseam falls 0.5 inches short, while at 5'8" 89 of every 100 riders reach the ground flat-footed.

Survey bodies' barefoot inseam against VTUVIA's 31.5-inch "Minimum seat to floor", counted at each height and rounded to whole riders.

VTUVIA's CMB PRO size chart prints a "Frame Seat Height" of 31.1 inches, near the product page's 31.5, and a "Minimum Seat to Floor" of 16.9 inches, the figure it also prints for the standover. The table uses the product page's 31.5, the figure printed with this model's own listing.

A saddle set for good pedaling sits too high for both feet at a light, so the CMB's way to stop is the low step: brake, slide forward off the saddle and stand astride the 16.9-inch frame.

VTUVIA's CMB size guide from its product page: a label for each length and a figure at each end of the 5'1" to 6'1" window; the drawing itself prints no numbers.

How upright will I sit?

Upright: the grips sit above the saddle at every seat height VTUVIA lists. VTUVIA prints a 43.3-inch handlebar height from the floor, so with the seat at its 39.4-inch highest the bar stands about 3.9 inches above it, and with the seat at its 31.5-inch lowest about 11.8 inches.

VTUVIA's ride-comfort graphic draws the posture it designs for: a trunk 60 to 90 degrees from level and elbows open to 150 to 160 degrees. In Priego Quesada et al., 2017, twenty recreational cyclists rated the most upright of three trunk positions the most comfortable.

VTUVIA publishes no reach or stack figure for the CMB, so no lean angle is computed here; the "Aluminum Alloy Adjustable" stem is how you tune it. If you reach down to the grips, raise the bars, and if your elbows lock straight and your weight slides back, lower them. On the 10-speed sibling, Scott Hardesty found "the seating position is excellent I'm sitting straight up".

How much weight rests on my wrists?

Little, because the bar sits above the saddle. A hand-load figure needs the grip's position on the frame, which is not published for the CMB; for scale, ten road racers on their brake hoods carried 15% of their body weight on the bars in Carahalios, 2015.

Sitting up moves your trunk's weight onto the saddle (Clauser et al., 1969 give each body segment's share), and in 36 riders padded gloves cut the pressure over the ulnar nerve by 10 to 28% (Slane et al., 2011). Hardesty's 10-speed came with a locking grip with "this nice Palm rest", and VTUVIA's close-up of the CMB's grip shows the same winged shape.

How do I set the saddle when it arrives?

Set it so your knee keeps a bend of 25 to 35 degrees at the bottom of the stroke (Peveler et al., 2007). Start from the heel: rest it on the pedal at the bottom of the stroke, and raise the saddle until that leg is straight.

In Peveler et al., 2005, the heel method put 70% of 19 trained cyclists inside that knee range, ahead of either inseam formula. VTUVIA's page lists a "Quick-release height adjustment" for the saddle, so it moves without tools; close the lever firmly before you ride.

For a softer seat, VTUVIA's 50 mm suspension seatpost comes in a CMB fitting, $129 on our shelf.

The fit arithmetic

One rule builds the saddle table: 109% of inseam, measured from the pedal axle to the top of the saddle. A 5'8" rider with the survey's median inseam of 32.6 inches gets a saddle 35.6 inches above the pedal axle, or 34.6 at 106% and 36.0 at 110.4%.

The LeMond method instead takes 88.3% of inseam from the crank axle, 28.8 inches for the same rider; add the crank's length and the two methods land close together.

VTUVIA's Dark blue side photograph, scaled to the 46.4-inch wheelbase, reproduced four of VTUVIA's lengths within 1.2%: the overall length, the chainstay, the step and the head tube. Placing a saddle on the frame also needs the crank's length, which VTUVIA does not print for the CMB and the photographs do not show clearly, so this page places no saddle, lean or hand load on the frame (Limitations).

The motor: 500 W at the cranks, 175 N·m

VTUVIA rates the CMB's mid-drive at 500 W, with "PEAK 820W" in its specification table and "750W Peak Mid-Drive Power" in the feature block on the same page, on a 48 V, 20 A controller. A September 2024 CMB PRO post gives "Peak 818W". The rating is the figure the class section reads against the statutes, and both of the page's peaks appear in the hills section.

The motor turns the chainring, and the gears multiply its pull. VTUVIA's FAQ describes it "Driving the crank instead of the wheel", so a low gear on a climb lets the same motor push harder at the rear wheel, and the gear you choose decides how fast the motor spins at a given road speed.

The torque is 175 N·m in VTUVIA's table, in the feature block ("175Nm Max Torque") and in the product record ("500W mid-drive motor with 175Nm torque"). That is torque at the cranks, before the gears. The range model caps its stand-in motor at Bafang's published 120 N·m, and run at VTUVIA's 175 its climbing figures do not change, because the motor's power runs out before its torque does.

The assist reads how hard and how fast you pedal. VTUVIA's table lists "Cadence Sensor & Torque Sensor", its feature text says the system "smart-senses your input and delivers seamless power exactly when needed", and the assist comes in "3 Modes x 5 Levels". Riding the 10-speed sibling, Hardesty could not feel the handover between the two sensors:

I couldn't tell when I was on Cadence and I couldn't tell when I was on torque.

Scott Hardesty on the 10-speed CMB PRO in an October 21, 2024 video, at the end of a ride run until the pack was empty.

The thumb throttle follows the assist level. On the 10-speed, Hardesty found that in level one "the bike takes off incredibly slow very controlled and very gently", and that from level five "it's going to take off a lot more aggressive". For a gentle start in a crowd, pick a low level before you press it.

Hub motors and mid-drives are set side by side in our e-bike motor guide. For the CMB in particular, the gear table shows in watt-hours what a well-chosen gear saves.

The battery: 48 V × 14.4 Ah = 691.2 Wh of LG cells

The pack stores 691.2 watt-hours, 48 volts times 14.4 amp-hours, in LG cells, and it runs the motor, the display and both lights. VTUVIA's highlight strip reads "691.2Wh LG", and on the 10-speed sibling Hardesty read off the same "48 volt 14.4 amp" pack.

VTUVIA's illustration of the CMB's pack inside the down tube; the glow and the cutaway are the drawing's.

VTUVIA prints the pack two more ways: its product record says "48V 15Ah", which at 48 volts would be 720 Wh, and its March 26, 2026 comparison lists 720 Wh beside the CMB's eight gears. Every figure here uses the table's 691.2 Wh.

The record calls it a "Removable battery for easy charging at home or office", and on the 10-speed Hardesty showed both ways: "you can charge it while it's in the bike with this charging port right here or you can remove it and charge it somewhere else". A replacement key set in a CMB PRO fitting is $89 on our shelf, and VTUVIA's 2 A charger in its CMB fitting is $99.

At 54.6 V and 2 A the charger delivers about 109 W, so 691.2 Wh needs about 6.3 hours before the charger's own losses, and VTUVIA's table says "About 7.5 Hours". Plug it in after dinner and it is full by morning.

How far the CMB 8-Speed goes: range by speed, gear, hill, load and cold

On a full pack, a 180 lb rider covers about 44 miles of flat road at 15 mph on the throttle, about 29 at 20 mph, and about 74 at 15 mph with easy pedaling. Hold 10 mph up a steady 8% grade with the motor doing all the work and the charge lasts about 11 miles.

To find your own figure:

1. Look up your speed and how much you pedal in the speed tables, and your cadence in the gear table.
2. Add the climbing: each 1,000 feet at 10 mph on the throttle costs 124 to 127 Wh on grades from 4 to 10% (the hills table).
3. Correct for your load and the temperature, then plan on three-quarters of the pack.

Each figure is one steady ride computed from VTUVIA's specification, a Bafang mid motor rated at the same 500 W, rolling resistance measured on 273 riders' commuter tires and a cycling-power model validated on an open road. The formula subsection works one ride through and sets the model beside a measured ride on the CMB's 10-speed sibling.

Does speed cut the CMB's range? Miles at each speed

Yes, and hardest near the top: about 64 miles at 10 mph on the throttle, about 29 at 20 mph. Going from 15 mph to 20 mph alone costs 15 of those miles, 44 at the slower pace and 29 at the faster.

Most of that goes to the air. Its drag grows with the square of your speed, and the power to push through it grows with the cube, so every extra mile an hour near the limit costs more than the last.

180 lb aboard and the motor doing all the work, with the chainring at its most efficient speed from 50 to 90 rpm, on flat ground at 77 °F, up to VTUVIA's 20 mph limit. The last column keeps back the quarter of the pack KIT's researchers found unused on one measured pedelec.

Pedal easily, about 75 W, and the 15 mph ride grows from 44 miles to 74. In these tables 75 W is easy and 150 W is steady; with the motor off, 75 W from your legs holds about 10.3 mph on the level and 150 W about 14.2 mph, so take the column closest to how you ride unassisted.

Each cell is the miles a full charge gives on flat ground with 180 lb aboard. At 15 mph the pack spends 15.8 Wh a mile with the motor doing everything and 9.4 Wh with easy pedaling. The 216-mile cell is the least certain: your legs do nearly all the work there, at a motor load for which neither Bafang's workbook nor any VTUVIA document read here prints an efficiency (Limitations, item 8).

The assist level on the display does not fix these miles by itself; the speed you hold and how much of the work you hand the motor do. VTUVIA's own range note makes the point in its list of what moves the figure: "the rider's weight, pedal assist level, throttle use, terrain, speed, weather, and towing weight".

Do gears save battery on the CMB?

Yes: on a mid-drive, the gear you are in changes what the motor spends. The motor turns the chainring, so the gear sets how fast it spins at a given road speed; the stand-in motor works best near its rated 115 rpm and turns more of the pack's energy into heat when it labors slowly under load.

Each cell is the pack's energy per mile on the throttle with 180 lb aboard at 77 °F, with the chainring turning at 50, 70 or 90 rpm; when you pedal, that is your cadence. The stand-in motor turns 130 rpm with no load and 115 rpm at its rating (Bafang's workbook).

The climb is where it counts: up a 4% grade at 15 mph the motor spends 57.2 Wh a mile at 50 rpm and 43.0 Wh at 90 rpm, about a quarter less for the same climb at the same speed. On the flat at 15 mph the gap is under a watt-hour a mile, 16.7 Wh at 50 rpm against 15.8 at 70.

VTUVIA's FAQ makes the same case for the eight gears, which it says "allows the mid-drive motor to operate at its most efficient RPM, extending your battery life". In practice, shift down before a climb or a stop so the chainring keeps turning briskly, at roughly 70 to 90 rpm.

How much battery does a climb cost?

Climbing 1,000 feet at 10 mph costs the pack 124 to 127 Wh on the throttle over grades of 4 to 10%, and 126 to 131 Wh with easy pedaling. About 90 Wh of that lifts rider and bike at the rear wheel; the rest is heat in the motor, the chain and the pack.

With 180 lb aboard and VTUVIA's 60 lb, the load is 240 lb. On the throttle up 8% at 10 mph each 1,000 feet costs 125 Wh, so the 691.2 Wh pack would lift you about 5,540 feet before it ran dry. The model counts no descents, so the coasting a hilly loop gives back is not in these figures.

Each row holds 10 mph with 180 lb aboard, the chainring at its most efficient speed. The watt-hours and throttle miles leave your legs out, and the easy column adds 75 W back. The last column is the fastest steady pace the motor holds alone on that grade within the 820 W peak in VTUVIA's table, never above 20 mph; "past the peak" means it cannot hold 10 mph there by itself.

VTUVIA prints the peak two ways, and the controller can pass more than either. The table says 820 W and the feature block 750 W, and a 48 V, 20 A controller allows 960 W. The throttle-only speeds at each:

Throttle only, 180 lb aboard, 77 °F. The middle column is the hills table's; the right-hand one is the controller's 48 V × 20 A, and the formula subsection sets a measured climb beside all three.

Past 10%, pedal in a low gear. At 12% the motor alone holds about 9.7 mph under the 820 W peak, and 75 W of easy pedaling lifts that to about 10.7; on 15% the throttle's 8.1 mph becomes about 9.0.

Put the climbing on top of your flat miles. Say you ride 10 miles each way at 15 mph on the throttle, with 400 feet of climbing at 6%: about 366 Wh, or 71% of the 518 Wh you plan on with a quarter held back. Stops, wind and broken pavement come on top, because the model holds one steady speed.

How much does a heavier rider or a full rack cost?

On the flat, extra weight costs a few miles; on a climb, a good many more. In the power model, each pound adds rolling drag and has to be lifted up every grade while the air's drag stays the same, so heavy and light loads drift further apart as the road tilts. Shopping on the rack costs the pack exactly what your own pounds do.

Rider plus everything carried, with VTUVIA's 60 lb for the CMB added to each row; throttle only. The 300 lb row is VTUVIA's rated total capacity.

A 200 lb rider with 30 lb of groceries reads the 230 lb row: about 41 flat miles at 15 mph. At the full 300 lb, the level 15 mph ride drops from 44 miles to 38, and from 280 lb up the throttle alone cannot hold 10 mph up an 8% grade within the 820 W peak, so plan to pedal on the steep parts (the hills table).

How much range does the cold take?

Colder air means shorter rides. The 44 miles of a 15 mph throttle ride at 77 °F fall to about 35 at freezing, 32 °F, and about 32 at 14 °F.

180 lb aboard on level ground. The central figures follow McMaster University's LG HG2 cell measurements at 77, 50, 32 and 14 °F for a 0.5C discharge, interpolated between, with the cells taken to be at the air's temperature. VTUVIA names LG cells but no cell model, so an LG cell with published cold data stands in.

The low bracket is the least capacity a Samsung data sheet reports at that temperature for a discharge of one to four hours (25R and 30Q at 32 °F, 35E at 14 °F); the high bracket is the most energy Casado and colleagues measured in 2025 at a gentler rate.

Below freezing three losses add up. At 32 °F the cells return about 89% of their energy at 77 °F, between 80 and 93% by source, and the air is about 9% denser by the U.S. Standard Atmosphere's gas law, so there is more of it to shove aside.

The tires roll harder in the cold as well. The model raises rolling resistance by 0.5% for every °F below 77 °F (0.9% per °C), between Rothhämel's fit for a 42 mm tire and Bicycle Rolling Resistance's road-tire average, and holds it level below 41 °F. On a cold morning, keep the pack indoors overnight and lock it in just before you go.

Heat pulls the other way (U.S. Standard Atmosphere): at 95 °F the cells keep about 99% of their energy, the air is about 3% thinner and the tires roll about 9% easier, so a 15 mph throttle ride gains a mile over 77 °F.

Do the tires and your posture cost range?

The tire counts for more than how you sit. VTUVIA's table lists a 26 × 2.4 tire and its feature block a 26 × 2.6; no drum test of either turned up, so the model uses the commuter-tire average Tengattini and Bigazzi measured across 273 everyday riders.

Level ground, 180 lb aboard, a full pack. All three coefficients come from Table 4 of the same field study, measured on riders' own tires.

Keep the tires at the pressure printed on the sidewall, since a soft tire rolls harder. Posture matters more as speed climbs: the model's drag area of 0.640 m² is what Tengattini and Bigazzi measured on 37 people riding upright cruisers, and leaning down to the 0.603 m² of their 90 mountain-bike riders turns a 20 mph throttle ride of 29 miles into 31.

VTUVIA's two range figures, as steady rides

Both range figures VTUVIA prints for the CMB 8-Speed match a steady ride the model can name. The product page gives 80 miles on pedal assist and 45 on the throttle, and its highlight strip and product record repeat the 80.

VTUVIA's 2024 posts give the belt-drive CMB PRO "Up to 70 Miles" (September 19) and "Up to 52 miles" (August 19) on its 720 Wh pack, a different pack from this bike's, so neither is mapped here.

The steady level-ground speed that uses all 691.2 Wh over VTUVIA's distance with 180 lb aboard: 80 miles allows 8.64 Wh a mile and 45 miles 15.36. A dash means no steady speed from 5 to 20 mph fits that column.

Read that way, the page's 80 miles means pedaling easily at about 14.6 mph the whole way, and its 45 on the throttle means holding about 14.7 mph, close to the model's own 44 miles at 15 mph.

Plan on three-quarters of your row. The KIT test bench used that share of its pack, which turns the 44-mile ride at 15 mph on the throttle into a planning figure of 33 miles.

The range formula, worked through

One equation sits under every range figure on this page: the 1998 model Martin and colleagues checked against power meters on an open road. It turns speed, weight, slope and air into the power the rear wheel must deliver to hold a steady ride in still air:

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

Here P is the rear wheel's power. Inside the brackets, m is the mass of rider, cargo and bike, g is gravity and θ the slope's angle; Crr, the tires' rolling-resistance coefficient, is 0.0074 here, a drag of 0.74% of the weight they carry. ρ is the air's density, CdA the drag area you present to the wind, and v your speed (Martin et al.).

On a bike with the motor at the cranks, four stages sit between the rear wheel and the cells:

1. The chain passes 97.7% of what reaches the chainring to the rear wheel (Martin and colleagues' chain efficiency); on the CMB that covers the motor's share as well as your legs'.
2. The chainring turns at your cadence, and the model picks the most efficient cadence from 50 to 90 rpm for each ride (Limitations).
3. The motor is modeled on a mid motor whose maker publishes its numbers: Bafang's 2021 OEM workbook lists the M600, MM G521.500.C, rated at 500 W with a maximum torque of 120 N·m and an efficiency of at least 80%, turning 130 rpm with no load and 115 at its rating at 48 V. It runs at 80% at its rating and less when lightly loaded, never above 120 N·m, with the pack's draw held to the 820 W peak in VTUVIA's table.
4. The cells lose a little energy as heat as they discharge, at the rate Arango, Lopez and Ceren measured on a 48 V pack.

The last step is two divisions: Wh per mile = pack watts ÷ mph, and range = 691.2 Wh × the share of its energy the cells still hold at that temperature ÷ Wh per mile.

The 44-mile ride, worked through: 180 lb aboard, flat ground, 15 mph, all of it on the throttle (Martin et al.). The rear wheel must deliver 167.2 W to hold that speed, 53.0 W against the tires and 114.2 W against the air, and through the chain that asks 171.1 W of the chainring.

With the chainring at 80 rpm, that is 20.4 N·m of torque. Built from Bafang's published figures as 3.526 N·m per amp, 0.425 Ω of winding resistance and 1.25 A with no load, the motor meets it on 7.0 A at 75% efficiency and draws 229.0 W.

With the pack's own losses added, the cells supply 237.0 W; at 15 mph that is 15.80 Wh a mile, and 691.2 Wh at 15.80 Wh a mile lasts about 43.7 miles, or 32.8 with a quarter of the pack held back.

Before it computes a ride, the model reproduces two published figures:

Each run first recomputes Martin and colleagues' Appendix I case (8.36 m/s, a 90 kg system on a 0.3% grade) and the Bafang motor's rated point, and stops if either comes out wrong.

A measured day on the 10-speed sibling. Scott Hardesty's ride, posted October 21, 2024, ran the 10-speed CMB PRO with the same 691.2 Wh pack until it stopped: "it showed that it was at 30 miles on the dot", and the reviewer's Strava read 31.6 miles. The rider's own figures: 5'9", 220 lb and a 32-inch inseam.

The ride ran mostly in "pedal assist number five", into what Hardesty called the "kind of wind that I was fighting into for the first half", with a steep climb taken partly on the throttle. With the rider's 220 lb on the throttle at a steady 20 mph over level ground, the CMB's limit as delivered, the model uses the pack in about 28.2 miles.

The pedaling added to that, and the wind and the climb took from it, so the measured 31.6 sits beside the model's figure rather than on it; the video holds no single steady speed to set against one row.

The reviewer's climb is a check on the hills table. Hardesty called it a hill that "starts off at 20 and then shoots up to 31"; with level five, the throttle and low gears, "we made it no problem", and on the throttle alone "it's getting slow but it hasn't quit" before "I got a pedal" near the top.

With the rider's 220 lb, the model's motor alone holds about 5.4 mph on 20% and 3.6 mph on 31% at the 820 W peak, and 6.3 and 4.2 mph at the controller's 960 W. Slow and still climbing is what the reviewer described (Limitations).

Brakes, lights and the controls

Both wheels stop through Logan hydraulic calipers on 160 mm rotors of martensitic stainless steel, by VTUVIA's table, and the product record names Logan for the 8-speed build. Hardesty's 10-speed sibling used Tektro brakes on rotors of the same size.

A CMB grip with its palm wing, the hydraulic brake lever and the thumb throttle, in VTUVIA's close-up.

The lights run off the main pack. VTUVIA's table lists a "48V 10W 150 Lux LED Headlight & 48V Rear Light". On the 10-speed, Hardesty switched the headlight on by holding the plus key, and its tail light grew brighter under braking: "when you hit the brakes it just gets brighter".

The CMB's 3.5-inch color display in VTUVIA's close-up: speed, battery percentage, assist level and trip.

VTUVIA's table describes the display as 3.5 inches, "Full Color,High Brightness,Adjustable Angle", and its feature text promises "real-time ride data with maximum clarity, even under direct sunlight". The screen on Hardesty's 10-speed showed the pack as a percentage, as VTUVIA's close-up does.

On the 10-speed the thumb throttle sat on the left grip ("this thumb throttle here on your left hand side"), and there was a walk mode: with assist at zero, hold the minus key. Hardesty tried it walking the bike over a bridge and found "a strong walk feature".

Fit a bell if yours arrives without one. VTUVIA's table lists the bell as "Not Included", while its product record mentions "Integrated lights and bell". Hardesty put a bell first on his list of changes for the 10-speed: "add a bell immediately to this bike especially if you live in a big city like I do".

Fork, tires, gears and water

The fork is sprung at the front only, and VTUVIA describes it two ways. The specification table names an "EXSHO Suspension Fork", while the feature block calls it a "100mm Travel Hydraulic Fork" and the product record a "Hydraulic front fork with 100mm travel".

The CMB's fork in VTUVIA's close-up, with a red-capped knob on top of one leg.

On the 10-speed, Hardesty found a fork with "100 mm of travel you can preload them and you can lock them out". If yours has the same knob, lock it for smooth roads and open it for broken ones.

The tires are 26 × 2.4 in VTUVIA's table and "26" x 2.6" Puncture-Proof Tires" in its feature block, which describes them as "anti-puncture reflective tires".

The CMB's front tire and its reflective sidewall stripe, in VTUVIA's close-up.

The gearing is Shimano: an 8-speed shifter, rear derailleur and cassette, by VTUVIA's table. On a mid-drive those eight gears serve the motor as well as your legs, which is the subject of the gear table.

VTUVIA's class note covers water. It says the bike is "built to the IP67-rated standard, making it suitable for riding through creeks, mud, and snow", then asks you to "avoid prolonged or intentional immersion in water" and to keep pressure washers and sprayers away (VTUVIA's CMB page).

For the 10-speed, Hardesty gave "an ipx rating of five". Whichever rating you go by, follow the product page's care note, and wipe the bike down with a damp cloth after a wet ride.

Weight, load and the rack

The CMB weighs 60 lb with its rack and fenders on VTUVIA's table, and the feature block adds that the 60 lb includes "the battery and all standard gear". Take the pack out before you lift the bike onto a hitch rack, and check that rack's per-bike limit.

A rider lifts a silver CMB on a boardwalk, in a photograph from VTUVIA's CMB page.

Keep yourself and everything on the bike under 300 lb. VTUVIA's table calls it "Total capacity" and the highlight strip "Payload Capacity"; the product record says the frame "supports up to 330 lbs", and the range tables plan on the table's 300.

The fitted rack is a platform for panniers and cargo, in VTUVIA's words a "stable platform for your pannier bags and cargo". The replacement rack VTUVIA lists for the CMB 8-Speed is rated by VTUVIA at 25 kg, about 55 lb, on our rack listing, where it is $99.

The CMB's rear rack in VTUVIA's close-up.

The Mercer fit test

The same seven Mercers of Fair Oaks, California, stand in for every reader we review for, so fit answers compare cleanly from one bike to the next (meet the Mercers). Each verdict below comes from a figure VTUVIA publishes, a row of the fit tables, or the California code section cited beside it.

Ruth, Dana and Maya fit the frame, and Ruth stops most easily by standing over the low step. Frank, Jack and Cole should measure their inseams before ordering, because from 5'9" up the median inseam passes VTUVIA's 33 inches, and Cole rides in a helmet under California law.

Is it UL certified?

VTUVIA says both the pack and the electrical system are: its specification lists "UL2271(Battery） UL2849(E-bike System)", its highlight strip reads "UL2271 & UL2849 Safety Certified", and its class note says the bike "is UL2849 certified for safety". In a December 29, 2024 post, VTUVIA named the CMB among models "certified by SGS TO UL2849".

Each standard covers its own part of the bike. UL 2849, "Electrical Systems for eBikes", lists "the drive unit, battery, battery management system (BMS), interconnecting wiring, and power inlet" within its minimum scope, while UL 2271 is the standard for "Batteries for Use In Light Electric Vehicle (LEV) Applications". Should a landlord, building manager or insurer ask for proof, we will request the certificate from VTUVIA in writing.

Has it been recalled?

No. We queried the Consumer Product Safety Commission's recall data on October 2, 2026 for VTUVIA, Vtuvia and vtuviaebike by title, product name and manufacturer, and read every field of the 623 bicycle, e-bike, battery and scooter recalls in the set we saved on September 25 for the brand and the name CMB.

None of them names VTUVIA or the CMB. The same queries first returned the recalls known to exist for Ancheer (1), Specialized (54) and Trek (24), which is what lets the empty result for VTUVIA stand.

The class question: 500 W rated, 20 mph as delivered

As VTUVIA ships it, the CMB is a Class 2 e-bike: pedal assist and a thumb throttle that both stop at 20 mph, on a motor rated at 500 W. VTUVIA's class note says the bike "comes out of the box as a Class II e-bike, equipped with pedal assist and throttle" and that "the default maximum speed is set to 20 MPH", and its table lists "Class 2".

The federal line sits in consumer-product law: 15 U.S.C. § 2085(b) describes a low-speed electric bicycle by its "fully operable pedals and an electric motor of less than 750 watts (1 h.p.)", and by a top speed on the motor alone, with a 170-pound rider, that "is less than 20 mph".

California's Vehicle Code § 312.5(a), as it read on September 28, 2026, covers a bicycle with fully operable pedals and a motor that "does not exceed 750 watts of power".

The CMB's rating clears both lines, and its two published peaks land in different places. A 500 W rating is "less than 750 watts" and does not "exceed 750 watts". The table's 820 W peak is over both lines; the feature block's 750 W is on the federal line and within California's; and neither statute says whether a rated or a peak figure is the one to read.

Both texts as read on September 28, 2026 (§ 2085(b), § 312.5(a)), against the figures VTUVIA prints for the CMB.

The federal definition shapes how the Consumer Product Safety Commission treats the product, but where and how you ride is set by your state, and each state words its own line. Our 50-state e-bike law atlas quotes them all, and our California page goes deeper into the one quoted here. Paths, parks and trails often add rules of their own, so read the posted sign or ask the agency in charge.

Parks, trails and federal land

Off the street, the land manager's own definition and route map decide where the CMB may ride, whatever its class. When a ride starts at a trailhead, find out who manages the land before you lift the bike off the car.

Each manager's own document answers its row, for the CMB and for any other e-bike.

The Bureau of Land Management draws its e-bike line in 43 CFR 8340.0-5(j): a cycle with fully operable pedals and a motor "of not more than 750 watts (1 h.p.)", in one of three classes. The CMB's 500 W rating and the feature block's 750 W meet "not more than 750 watts", and the table's 820 W peak goes past it.

Paragraph (a)(5) of that section keeps an e-bike out of the off-road vehicle rules only while three things all hold: roads and trails "upon which mechanized, non-motorized use is allowed", a motor not "exclusively propelling the e-bike for an extended period of time", and a field office that "has expressly determined" e-bikes should be treated like non-motorized bicycles.

If any one of the three fails, the CMB is an off-road vehicle on that ground, penalties and all. 43 CFR 8340.0-7 sets the penalty for breaking the off-road rules of subparts 8341 and 8343 at "a fine of not more than $1,000 or imprisonment for not longer than 12 months, or both". A long stretch on the thumb throttle alone fails the second condition by itself.

National Forests go a step further. The Forest Service's notice at 87 FR 41278 records directives for "managing all classes of e-bikes as motor vehicles", and where a district has published its motor vehicle use map, 36 CFR 261.13 forbids operating a motor vehicle "other than in accordance with those designations". Our public-land e-bike guide goes through each federal land agency's rules.

Green flags / Red flags

Green flags

• A 16.9-inch step that 95 of every 100 riders at 5'1" clear by 10.8 inches or more, and a 31.5-inch lowest seat that most riders from 5'6" up sit on with both feet flat.
• A 500 W mid-drive with 175 N·m that pulls through eight Shimano gears, so a brisk cadence up a 4% grade at 15 mph spends about a quarter less of the pack than a slow one.
• 44 computed miles on one charge for a 180 lb rider holding 15 mph on the throttle over flat ground, and 74 with easy pedaling.
• About 11.2 mph up a 10% grade on the motor alone with 180 lb aboard, within the 820 W peak in VTUVIA's table.
• Logan hydraulic brakes on 160 mm rotors, a 150 lux headlight, a rear light and a color display.
• UL 2849 for the e-bike system and UL 2271 for the battery, by VTUVIA's specification.
• $1,399, VTUVIA's own price, in Metallic Silver or Dark blue, with the CMB's charger ($99), key set ($89), fenders ($99), rack ($99) and suspension seatpost ($129) on our shelf.

Red flags

Each is about fit: who the CMB is wrong for, and what to do instead.

• Wrong if your inseam passes 33 inches, the top of VTUVIA's recommended range: read our Zeal XT8 review, a step-through VTUVIA sizes to 6'2" with an inseam up to 34 inches.
• Wrong if you stand 5'5" or shorter and need to sit flat-footed. At the 31.5-inch lowest seat, 34 or fewer of every 100 riders at those heights do; stop by standing over the 16.9-inch step, or read the VTUVIA SX20 review, whose lowest seat is 30.7 to 31.4 inches off the floor by VTUVIA's two figures.
• Wrong if you want the lowest price on a VTUVIA step-through. The Zeal LT7 puts a 500 W hub motor, a torque sensor and a 624 Wh pack on a step-through frame for $1,099.
• Wrong if rider and cargo together pass 300 lb. That is VTUVIA's table figure for the CMB; the Zeal LT7 and the Zeal XT8 each carry 350 lb by VTUVIA's figures.
• Wrong if a child is to ride on the back. The CMB has no passenger seat; the VTUVIA SF20H carries a second seat on its rack, and its review sets that seat against California's passenger rule.
• Wrong if the bike has to fold or travel in a trunk. VTUVIA lists the CMB's frame as not foldable; the VTUVIA SX20 folds and steps through at 13.8 or 15.4 inches.
• Wrong for paths open to Class 1 bikes only. The thumb throttle puts the CMB in Class 2, so send us the path's name and we will read its rule for you.

Buy it if / Buy something else if

Buy it if you ride city streets with real hills, want the motor's pull to run through gears, and like a frame you step through at 16.9 inches, with hydraulic brakes, a rack, fenders and lights fitted, for $1,399. The model gives a 180 lb rider 44 miles at 15 mph on the throttle over flat ground, or 74 with easy pedaling.

It suits riders from 5'1" to about 5'8" whose inseam sits inside VTUVIA's 27 to 33 inches, who stop by standing over the step, and whose load stays under 300 lb.

At $1,399 you get a 500 W mid-drive with 175 N·m, a removable 691.2 Wh LG pack, torque and cadence sensing, eight Shimano gears, Logan hydraulic brakes, a 150 lux headlight, a rear light, a rack and fenders. Spread over our listing's 12-month Shop Pay plan at 15% APR, it comes to $126.27 a month, $1,515.24 in total.

Buy something else if you want the lowest price, carry more than 300 lb, need a passenger seat or a folding frame, or have an inseam past 33 inches: the red flags send each of those to a bike we sell. If price is the only reason, the Zeal LT7 keeps a step-through frame for $1,099.

Our e-bike reviews hub collects every review we have published, and our VTUVIA brand profile sets the CMB beside the other VTUVIAs we can ship, with range, fit and price for each.

The CMB in Dark blue, the picture VTUVIA's listing ties to that colorway.

Before you buy: the checklist

Go through these ten before you spend $1,399, beginning with where you will ride.

1. Start with your route: read your state's e-bike definition, then the signs on each path and trail you use.
2. Hold the CMB against them: a 500 W rating, peaks of 820 W and 750 W in VTUVIA's two figures, Class 2, and 20 mph as it leaves VTUVIA.
3. Measure your inseam and find your row in the saddle table; it should sit inside VTUVIA's 27 to 33 inches.
4. Set your height beside VTUVIA's 5'1" to 6'1", and if you are 5'9" or taller, read the red flags first.
5. Practice the stop: brake, slide forward off the saddle, and stand astride the 16.9-inch step.
6. Weigh yourself with your cargo, and keep the total under 300 lb.
7. Keep the rack's load inside the 55 lb that VTUVIA rates its replacement CMB rack at.
8. Find your steepest climb in the hills table, and plan to shift down and pedal past 10%.
9. Look up your commute in the range tables, add the hills and the cold, and keep a quarter of the charge back.
10. If your building, city or a rebate program wants a certificate, ask us before you order, and we will request VTUVIA's documents in writing.

Buying it from us

Why buy the CMB 8-Speed from Redtail

Our listing priced the CMB at $1,399 against a regular $1,899 on October 2, 2026, in both colorways, the same as VTUVIA's page that day.

A change-of-mind return follows the refund policy: ask within 72 hours of delivery with the bike unopened in its factory packaging, and the refund is reduced by a 15% restocking fee and the cost of return shipping, while an order you cancel carries a 3% transaction fee. Questions about fit, range or the rules on your route cost nothing, and asking them first is the better order of events.

Frequently asked questions

How far can the VTUVIA CMB 8-Speed go on one charge?

VTUVIA's product page lists 80 miles on pedal assist and 45 on the throttle. At 180 lb on flat ground, you get about 44 miles at 15 mph on the throttle by the model, 29 at 20 mph, or 74 at 15 mph if you pedal easily; add 124 to 127 Wh for every 1,000 feet you climb at 10 mph on the throttle (range).

What is the top speed of the CMB 8-Speed?

20 mph. VTUVIA ships it as a Class 2 bike, and its class note says "the default maximum speed is set to 20 MPH" (the class section).

Is the CMB 8-Speed street legal, and which class is it?

VTUVIA delivers it as a Class 2 e-bike, with pedal assist and a thumb throttle that stop at 20 mph. Its 500 W rating sits under both the federal "less than 750 watts" and California's "does not exceed 750 watts", VTUVIA prints its peak as 820 W and as 750 W, and your state decides where you may ride it (the class section).

What is the difference between the CMB 8-Speed and the CMB PRO?

The CMB PRO name has covered a single-speed belt-drive bike with a 720 Wh pack and a 10-speed chain bike, both from 2024. The CMB 8-Speed you can order today has a Shimano 8-speed chain drivetrain, Logan hydraulic brakes and a 691.2 Wh pack in VTUVIA's table, and VTUVIA's class note on its page still calls it the CMB PRO (what it is).

Is a mid-drive better than a hub motor?

It depends on your riding. A mid-drive like the CMB's pulls through the gears, so on a climb a low gear helps it, and up a 4% grade at 15 mph a brisk cadence spends about a quarter less battery than a slow one; a hub motor like the Zeal LT7's leaves the gears to your legs and costs $300 less (the gear table).

What is a mid-drive e-bike?

A mid-drive puts the motor at the cranks, where the pedals turn, instead of in a wheel hub. On the CMB the motor drives the chainring, and its power reaches the rear wheel through the chain and eight gears, the same path as your pedaling (the motor section).

Does the CMB 8-Speed have a throttle?

Yes, a thumb throttle, along with pedal assist in "3 Modes x 5 Levels", and both stop at 20 mph. On the 10-speed sibling, Scott Hardesty found the throttle starts gently in assist level one and pulls harder in level five (the motor section).

How much does the CMB 8-Speed weigh?

60 lb with its rack and fenders, by VTUVIA's table, which its feature block says includes "the battery and all standard gear". Lift it with the pack out, and check your car rack's per-bike limit before loading it (the weight section).

How much weight can the CMB 8-Speed carry?

Plan on 300 lb for you and everything on the bike, VTUVIA's "Total capacity", though its product record says "supports up to 330 lbs". Loaded to 300 lb, the model's level 15 mph ride on the throttle comes to about 38 miles (the weight table).

Does the CMB 8-Speed have a torque sensor?

Yes. VTUVIA's table lists "Cadence Sensor & Torque Sensor", so the assist responds to how hard and how fast you pedal; on the 10-speed sibling, Hardesty could not feel the switch between the two (the motor section).

Can the CMB 8-Speed climb hills?

Yes, and with you pedaling in a low gear it climbs steep ones. On the throttle alone with 180 lb aboard it holds about 15.4 mph up 6% and about 11.2 mph up 10% within the 820 W peak in VTUVIA's table, and Hardesty took the 10-speed sibling up a grade given in the video as 20 to 31% (the hills table).

What height rider does the CMB 8-Speed fit?

On VTUVIA's page the range is 5'1" to 6'1" with a 27- to 33-inch inseam. If you are 5'9" or taller, your inseam may run past VTUVIA's 33 inches, so measure it first (fit).

Is the CMB 8-Speed a good e-bike for seniors?

For many older riders it is: you step through a 16.9-inch frame instead of swinging a leg over, the grips sit above the saddle for an upright seat, and the torque sensor eases you away from a stop. Below 5'6" you will usually stop by standing over the step, since the lowest saddle sits 31.5 inches up (fit).

How long does the CMB 8-Speed battery take to charge?

Plan on about 7.5 hours, VTUVIA's figure. The arithmetic agrees: 54.6 V at 2 A is about 109 W, which fills 691.2 Wh in about 6.3 hours before the charger's own losses (the battery section).

Can you ride the CMB 8-Speed in the rain?

Yes. VTUVIA's class note rates it to "the IP67-rated standard" for creeks, mud and snow, while asking you to avoid long immersion and pressure washers; after a wet ride, a damp cloth is all it needs (the water section).

Is the CMB 8-Speed UL certified?

VTUVIA says so: its specification lists "UL2271(Battery） UL2849(E-bike System)", and a December 29, 2024 post names the CMB among models "certified by SGS TO UL2849". If you need the certificate for a landlord or insurer, we will request it from VTUVIA in writing (UL certification).

What does the CMB 8-Speed cost to run?

At 15 mph on the throttle with 180 lb aboard, it uses about 15.8 Wh a mile, and a full charge puts 0.69 kWh into the pack before the charger's losses; multiply that by your electric rate for the cost of a charge. Pedal easily and the figure falls to 9.4 Wh a mile (the speed tables).

What warranty does the CMB 8-Speed have?

If something goes wrong with a CMB you bought from us, you deal with us: send photos and your order number, and we handle the claim from start to finish. Under our refund policy, a bike that will not power on or charge, shows an error code or has a faulty part is covered, and if you ask, we will send you the terms for your CMB in writing before you buy.

Is the VTUVIA CMB 8-Speed worth it?

At $1,399 on our store (regular $1,899, read October 2, 2026) with free contiguous-US shipping, you get a step-through with a 175 N·m mid-drive, eight gears, a 691.2 Wh pack, hydraulic brakes, a rack and fenders. It suits you best from 5'1" to about 5'8", riding hilly city streets most days (the verdict).

Can I finance the CMB 8-Speed?

Yes. On October 2, 2026, Shop Pay on our listing offered 12 payments of $126.27 a month at 15% APR for the $1,399 CMB, $1,515.24 in total, along with 3- and 6-payment plans at the same APR.

Limitations of this review

Twenty-eight things this review cannot settle, set out so you can weigh them.

1. We sell this bike. Give the red flags the same weight as the green ones.
2. This review is specification-verified. Its figures come from VTUVIA's published pages, statutes, our store record, the research the range and fit sections cite, and arithmetic shown on the page.
3. Each range figure is one steady ride: one speed on one grade, with no wind and no stops. Starts, stops, headwinds and soft ground all cost more.
4. A Bafang mid motor stands in for VTUVIA's. VTUVIA publishes the rating, both peaks, the torque and the controller, and none of the documents read here names the motor's maker or its internals. At 82% efficiency instead of Bafang's 80% floor, the 15 mph throttle ride rises from 44 miles to 46.
5. The rated-power reading is the model's. Read VTUVIA's 500 W on a comparable motor rated at 750 W instead, and the 15 mph throttle ride comes to 42 miles and the 20 mph ride stays at 29.
6. The model caps torque at the stand-in's 120 N·m, under VTUVIA's 175; run at 175, no figure on this page moves, because the motor's power limits every climb first.
7. VTUVIA prints three peaks, 820 W in the table, 750 W in the feature block and 818 W in a 2024 post. The hills table uses 820 W, and the bracket table prints 750 W and the controller's 960 W beside it.
8. The model has no measured check at light motor load. Where your legs do most of the work, as in the steady-pedaling column at 15 mph, the figure rests on motor losses at a load for which neither Bafang's workbook nor any VTUVIA document read here prints an efficiency.
9. The gear table prices cadences, not gears. VTUVIA prints no chainring or cassette sizes for the CMB, so the model assumes one of the eight gears puts the chainring between 50 and 90 rpm at each speed and grade.
10. The measured day is on the 10-speed sibling, which shares the 691.2 Wh pack but not the gears or brakes. The rider's assist level and speed changed through the ride, the grades are the reviewer's own figures, and later in the video the same hill is called a 31-degree climb; the model reads the percent figures.
11. Every figure assumes VTUVIA's 691.2 Wh. At the 720 Wh the product record's 15 Ah and a March 2026 post imply, the 15 mph throttle ride rises from 44 miles to 46. The planning column holds back the quarter KIT's researchers found unused on one measured pedelec.
12. The tire coefficient is a field average. No drum test of the CMB's tire was found, so the model uses the commuter-tire mean of 273 riders, bracketed by slick tires and one standard deviation up.
13. The cold figures rest on one cell's laboratory data. VTUVIA names LG cells without a cell model, so the central line uses McMaster University's measured LG HG2, bracketed by other published cells.
14. VTUVIA prints two capacities, 300 lb in the table and highlight strip and "supports up to 330 lbs" in the product record; the page plans on 300.
15. VTUVIA describes the fork two ways, an "EXSHO Suspension Fork" in the table and a "100mm Travel Hydraulic Fork" in the feature block and record.
16. VTUVIA prints two tire widths, 2.4 inches in the table and 2.6 in the feature block.
17. VTUVIA lists the bell two ways, "Not Included" in the table and "Integrated lights and bell" in the product record.
18. VTUVIA prints the lowest seat three ways: 31.5 inches on the product page, and a "Frame Seat Height" of 31.1 and a "Minimum Seat to Floor" of 16.9 on its CMB PRO size chart. The flat-foot table uses 31.5.
19. VTUVIA names the bike more than one way. The page title says CMB 8-Speed, the class note CMB PRO, and the gallery file of the Metallic Silver picture "CMB10S"; no photograph's cassette can be counted, so each caption claims only what is in the frame and the colorway VTUVIA's listing ties to it.
20. The saddle table measures from the pedal axle. VTUVIA prints its seat range from the floor and no crank length or crank-axle height, so the page cannot say whether the seat reaches a given rider's setting, only what that setting is.
21. VTUVIA's photograph could not place the saddle. Scaled to the 46.4-inch wheelbase, it matched the overall length, the chainstay, the step and the head tube within 1.2%, but the crank's pedal end cannot be read on it or on VTUVIA's other side views, so no saddle position, lean to the grips or hand load was measured. The horizontal top tube and the wheel diameter were recorded and not counted.
22. The handlebar figures use VTUVIA's one handlebar height, 43.3 inches, measured at a stem setting VTUVIA does not state; the stem adjusts, so your bar may sit higher or lower.
23. The flat-foot figures set a barefoot inseam against the saddle's top height. Shoes, the saddle's width and tilting the bike all change what you feel at a stop.
24. The fit figures use the US Army's ANSUR II bodies: 6,068 soldiers aged 17 to 58, measured from 2010 to 2012, who are not the US public; your own inseam decides your row.
25. The 109% formula is a starting point. In 19 trained cyclists it put 55 to 65% inside the 25-to-35-degree knee range and the heel check 70%, so let your knee and heel settle the final height.
26. The reviewer's observations come from the 10-speed sibling. Its throttle side, walk mode, brake light, fork adjustments and water rating are the reviewer's; check the same features on yours when it arrives.
27. The certification is VTUVIA's statement. The pages read here print the standards, not a certificate number; if you need one, we will request VTUVIA's documents in writing.
28. The price and the stock were read on October 2, 2026, and either can change, as can VTUVIA's stock, our part prices and the Shop Pay terms.

The bottom line

For $1,399, the CMB 8-Speed puts a 500 W mid-drive with 175 N·m and a 691.2 Wh LG pack on a step-through frame with Logan hydraulic brakes, eight Shimano gears, a rack, fenders, a headlight and a rear light.

With 180 lb aboard, it computes to about 44 flat miles at 15 mph on the throttle, or 74 with easy pedaling; every 1,000 feet of climbing on the throttle at 10 mph adds 124 to 127 Wh, and a brisk cadence on a climb saves about a quarter of what a slow one spends.

It does its best work under a rider from 5'1" to about 5'8" who rides hilly city streets, shifts down before the climbs, stops by standing over the 16.9-inch step, and keeps the load under VTUVIA's 300 lb.

Through Shop Pay on our listing, it comes to $126.27 a month over 12 months at 15% APR.

Settle two things before you pay: your inseam against the saddle table, and your steepest daily climb against the hills table. Send us your usual route and we will check its climbs and its path rules before you order.

Source register

What each document behind this review supports.

T1 is the record itself from whoever issued it: a statute, the maker's product pages, record and posts, and our own store record.

T2 is a party's own publication about its product or its measurements: the motor maker's workbook, published research, and a reviewer's recorded ride.

Expiry conditions

Re-read this page if VTUVIA changes the CMB's price, specification, motor rating, either peak, torque, pack, range figures, speed, class note, weight, capacity, size guide, rider window or FAQ, or if VTUVIA publishes a crank length, gear sizes or a certificate number for the CMB; and re-read it if the price, the stock, the part prices or the Shop Pay terms change on our store.

Re-read it as well if a recall is published naming VTUVIA, if California amends §§ 312.5, 21204, 21212 or 21213, or if the BLM or the Forest Service changes its e-bike rules. Verified October 2, 2026.

References

The full bibliographic record for each document cited above, with the date it was retrieved.

1. VTUVIA, VTUVIA CMB 8-Speed Ebike — product page (highlight strip, feature blocks, ride-comfort graphic, Specs table, Size guide and drawing, the notes under the table, FAQs, as rendered for the US market). Retrieved September 28 and October 2, 2026. https://vtuviaebike.com/products/cmb-mid-drive-500-watt-electric-city-bike-vtuvia-ebike
2. VTUVIA, VTUVIA CMB 8-Speed Ebike — product record, variant prices, compare-at prices, availability and description. Retrieved September 28 and October 2, 2026. https://vtuviaebike.com/products/cmb-mid-drive-500-watt-electric-city-bike-vtuvia-ebike.json
3. VTUVIA, CMB PRO Size Chart. Retrieved September 28, 2026. https://vtuviaebike.com/pages/size-chart
4. VTUVIA, Meet the VTUVIA CMB PRO - A city e-bike that meticulously considers every detail ! (July 7, 2024; dated July 8 above its text), the single-speed belt drive. Retrieved September 28, 2026. https://vtuviaebike.com/blogs/news/meet-the-vtuvia-cmb-pro-the-e-bike-everyones-talking-about
5. VTUVIA, The Best 500 Watte Electric Bikes for Adults in 2024 (August 19, 2024; dated August 20 above its text), the belt-drive CMB PRO's "Up to 52 miles". Retrieved September 28, 2026. https://vtuviaebike.com/blogs/news/the-best-500-watte-electric-bikes-for-adults-in-2024
6. VTUVIA, 5 Best E-Bikes for Tall Riders (September 19, 2024), the belt-drive CMB PRO's 720 Wh pack, "Peak 818W" and "Up to 70 Miles". Retrieved September 28, 2026. https://vtuviaebike.com/blogs/news/5-best-e-bikes-for-tall-riders
7. VTUVIA, The Best 10-Speed E-Bike of 2024: The Upgraded CMB Pro (October 9, 2024; dated October 10 above its text), the 10-speed chain version. Retrieved September 28, 2026. https://vtuviaebike.com/blogs/news/the-best-10-speed-e-bike-of-2024-the-upgraded-cmb-pro
8. VTUVIA, Why does UL certification matter? (December 29, 2024), the CMB "certified by SGS TO UL2849". Retrieved September 28, 2026. https://vtuviaebike.com/blogs/news/why-does-ul-certification-matter
9. VTUVIA, VTUVIA CMB Pro vs Euphree Falcon 2: Which Commuter Electric Bike Wins? (March 26, 2026; dated March 31 above its text), the 8-speed CMB's "720Wh". Retrieved September 28, 2026. https://vtuviaebike.com/blogs/news/vtuvia-cmb-pro-vs-euphree-falcon-2
10. US Government Publishing Office, 15 U.S.C. § 2085 — Low-speed electric bicycles, subsection (b). Retrieved September 28, 2026. https://www.govinfo.gov/content/pkg/USCODE-2024-title15/html/USCODE-2024-title15-chap47-sec2085.htm
11. California Legislative Information, California Vehicle Code § 312.5, subdivision (a). Retrieved September 28, 2026. https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=VEH&sectionNum=312.5.
12. California Legislative Information, California Vehicle Code § 21204, subdivision (b). Retrieved September 28, 2026. https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=VEH&sectionNum=21204.
13. California Legislative Information, California Vehicle Code § 21212, subdivision (a). Retrieved September 28, 2026. https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=VEH&sectionNum=21212.
14. California Legislative Information, California Vehicle Code § 21213, subdivision (a). Retrieved September 28, 2026. https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=VEH&sectionNum=21213.
15. Bureau of Land Management, 43 CFR § 8340.0-5 — Definitions, paragraphs (a)(5) and (j). Retrieved September 28, 2026. https://www.ecfr.gov/current/title-43/subtitle-B/chapter-II/subchapter-H/part-8340/subpart-8340/section-8340.0-5
16. Bureau of Land Management, 43 CFR § 8340.0-7 — Penalties. Retrieved September 28, 2026. https://www.ecfr.gov/current/title-43/subtitle-B/chapter-II/subchapter-H/part-8340/subpart-8340/section-8340.0-7
17. Forest Service, US Department of Agriculture, 36 CFR § 261.13 — Motor vehicle use. Retrieved September 28, 2026. https://www.ecfr.gov/current/title-36/chapter-II/subchapter-B/part-261/subpart-A/section-261.13
18. US Forest Service, Directive Publication Notice, 87 FR 41278 (July 12, 2022), recording the final e-bike directives issued March 31, 2022. Retrieved September 28, 2026. https://www.federalregister.gov/documents/2022/07/12/2022-14777/directive-publication-notice
19. UL Standards & Engagement, UL 2849 — Electrical Systems for eBikes, scope. Retrieved September 28, 2026. https://www.shopulstandards.com/ProductDetail.aspx?productId=UL2849
20. UL Standards & Engagement, UL 2271 — Batteries for Use In Light Electric Vehicle (LEV) Applications. Retrieved September 28, 2026. https://www.shopulstandards.com/ProductDetail.aspx?productId=UL2271
21. US Consumer Product Safety Commission, Recall data, title, product-name and manufacturer queries for VTUVIA, Vtuvia and vtuviaebike, a full-field read of a 623-record corpus, and controls Ancheer / Specialized / Trek. Retrieved October 2, 2026. https://www.saferproducts.gov/RestWebServices/Recall?format=json&RecallTitle=VTUVIA
22. Redtail eBikes, Shipping policy. Retrieved October 2, 2026. https://redtailebikes.com/policies/shipping-policy
23. Redtail eBikes, Refund policy. Retrieved October 2, 2026. https://redtailebikes.com/policies/refund-policy
24. Redtail eBikes, VTUVIA CMB 8-Speed listing (price, compare-at price, availability, Shop Pay plan table) and VTUVIA parts (prices, fittings and the rear rack's rating). Retrieved October 2, 2026. https://redtailebikes.com/products/vtuvia-cmb-8-speed
25. Bafang, BAFANG Workbook OEM 2021, the M600 mid motor MM G521.500.C. Retrieved September 23, 2026. https://www.bafang-e.com/Uploaded/Labels/BAFANG%20Workbook%20OEM%202021.pdf
26. 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). Retrieved September 23, 2026. https://collections.lib.utah.edu/dl_files/b4/8e/b48ef26086091662c561e673d7bd990d77868437.pdf
27. Tengattini, S. and Bigazzi, A., Physical characteristics and resistance parameters of typical urban cyclists, Journal of Sports Sciences 36(20):2383–2391 (2018). Retrieved September 23, 2026. https://civil-reactlab.sites.olt.ubc.ca/files/2022/11/Tengattini_2018_Physical-characteristics-and-resistance-parameters-of-typical-urban-cyclists.pdf
28. 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). Retrieved September 23, 2026. https://mdpi-res.com/d_attachment/wevj/wevj-12-00059/article_deploy/wevj-12-00059.pdf
29. Schmitt, M., Decker, S. and Doppelbauer, M., Measuring and Characterization of a Pedal Electric Cycle (Pedelec) on a Full System Test-Bench with Full Range Emulation of a Cyclist, EPE'19 ECCE Europe (IEEE, 2019). Retrieved September 23, 2026. https://publikationen.bibliothek.kit.edu/1000100371/50695920
30. Kollmeyer, P. et al., LG 18650HG2 Li-ion Battery Data and Example Deep Neural Network xEV SOC Estimator Script, Mendeley Data, V2 (McMaster University). Retrieved September 23, 2026. https://doi.org/10.17632/b5mj79w5w9.2
31. Samsung SDI, INR18650-25R specification. Retrieved September 23, 2026. https://e2e.ti.com/cfs-file/__key/communityserver-discussions-components-files/196/4628.130109_5F00_INR18650_2D00_25R-Cell-SPEC-_2800_3_2900_-_2800_1_2900_.pdf
32. Samsung SDI, INR18650-30Q data sheet. Retrieved September 23, 2026. https://e2e.ti.com/cfs-file/__key/communityserver-discussions-components-files/196/INR18650_2D00_30Q_5F00_datasheet.PDF
33. Samsung SDI, INR18650-35E technical information. Retrieved September 23, 2026. https://enerpower.de/wp/wp-content/uploads/2016/03/Technical_Information_INR18650-35E.pdf
34. Casado, A. et al., Journal of Power Sources (2025), low-temperature discharge measurements. Retrieved September 23, 2026. https://doi.org/10.1016/j.jpowsour.2025.236552
35. NOAA, NASA and US Air Force, U.S. Standard Atmosphere, 1976 (NOAA-S/T 76-1562). Retrieved September 23, 2026. https://ntrs.nasa.gov/api/citations/19770009539/downloads/19770009539.pdf
36. Bicycle Rolling Resistance, Rolling resistance and temperature test. Retrieved September 23, 2026. https://www.bicyclerollingresistance.com/specials/crr-temperature-test
37. Rothhämel, M., Rolling resistance of bicycle tyres and its temperature dependence, International Journal of Vehicle Design (2023). Retrieved September 23, 2026. https://www.inderscience.com/filter.php?aid=132317
38. Scott Hardesty, VTUVIA CMB PRO: Mid-drive, 10 Speeds, Cadence and Torque Sensor Premium Commuter (October 21, 2024), video and captions. Retrieved October 2, 2026. https://www.youtube.com/watch?v=LT6C0tyu4fk
39. US Army, For good measure: Natick releases raw data from Army-wide anthropometric survey (ANSUR II, 2012). Retrieved September 25, 2026. https://www.army.mil/article/188601/for_good_measure_natick_releases_raw_data_from_army_wide_anthropometric_survey
40. Peveler, W. W., Pounders, J. D. and Bishop, P. A., Effects of Saddle Height on Anaerobic Power Production in Cycling, Journal of Exercise Physiology online (February 2005). Retrieved September 25, 2026. https://www.asep.org/asep/asep/JEPonlineFEBRUARY2005_PevelerSaddle.doc
41. Peveler, W. W. and Green, J. M., Comparison of saddle height selection methods, PubMed 18076230 (2007). Retrieved September 25, 2026. https://pubmed.ncbi.nlm.nih.gov/18076230/
42. Ferrer-Roca, V. et al., A comparison between static and dynamic methods for saddle height adjustment, PubMed 22190163 (2012). Retrieved September 25, 2026. https://pubmed.ncbi.nlm.nih.gov/22190163/
43. Priego Quesada, J. I. et al., Effect of bike-fit in the perception of comfort, PubMed 27490817 (2017). Retrieved September 25, 2026. https://pubmed.ncbi.nlm.nih.gov/27490817/
44. Slane, J. et al., The influence of glove and hand position on pressure over the ulnar nerve during cycling, PubMed 21458120 (2011). Retrieved September 25, 2026. https://pubmed.ncbi.nlm.nih.gov/21458120/
45. Carahalios, A., Measured load on the handlebars of road racers (University of Colorado, 2015). Retrieved September 25, 2026. https://scholar.colorado.edu/downloads/70795789x
46. Clauser, C. E., McConville, J. T. and Young, J. W., Weight, Volume, and Center of Mass of Segments of the Human Body (1969). Retrieved September 25, 2026. https://ntrs.nasa.gov/api/citations/19700027497/downloads/19700027497.pdf