Duotts C29 Pro: 720 Watt-Hours, and 25 or 52 km/h

The Duotts C29 Pro is one product page wearing two motors. Duotts.com, the C29 URL, read 17 October 2026, titles the bike C29 and then says the model is C29 Pro, upgraded from the C29. The single-battery price is €819, struck from €1,149. One thousand one hundred forty-nine minus 819 is €330. A code on the page, DUOTTS-C29, is another €30. This desk did not check out, so €789 is the arithmetic, not a receipt. The pack is 48 volts and 15 amp-hours. Forty-eight times 15 is 720 watt-hours. The cart does not print 720. Tesztarena, 12 October 2026, does. A Geekbuying deal on 7 October sold a dual-battery version at €1,069 with the code C29Produal, two 48-volt 15-amp-hour packs. Forty-eight times 30 is 1,440 watt-hours, if the second pack matches the first. The official page this desk opened was the single, and it did not show that dual price.

Twenty-five kilometers an hour is not fifty-two

The EU line is 250 watts and 25 km/h. Twenty-five divided by 1.609 is 15.5 mph. That is the European assisted-bicycle ceiling, not a U.S. class. The international line is 750 watts. The M is capped at 45 km/h. Forty-five divided by 1.609 is 28.0 mph. The L is capped at 52 km/h. Fifty-two divided by 1.609 is 32.3 mph. A tile on the same page also says 25 km/h, next to the words EU and international. The class chart stops a Class 3 at 28 mph of pedal assist, and it stops a Class 2 throttle at 20 mph. Thirty-two miles an hour is past both. The page also claims a pure-electric range of 50 to 60 km, which is a motor-only mode. A motor-only mode is a throttle. The page does not say the throttle is locked at 20 mph on the international bike. Do not buy the L and tell a ranger it is a Class 3 because the M’s 45 km/h is close to 28 mph. Close is not the cell.

Seven hundred twenty watt-hours, three range sentences

Seven hundred twenty divided by 90 is 8.0 watt-hours per kilometer, if the 90 km line and the 720 are a pair. Seven hundred twenty divided by 80 is 9.0. Divided by 100 it is 7.2. The motor-only band is 50 to 60 km. Seven hundred twenty divided by 50 is 14.4 watt-hours per kilometer. Divided by 60 it is 12.0. Those are five rates from one pack, and the page says the 90 km figure is at 75 kg, in assist, and that the real ride moves with temperature, terrain, and the rider. It does not say which assist level, or whether the 80-to-100 sentence is the same test as the 90. The range page is why a band is not a loop. The charger is 54.6 volts at 2 amps. Fifty-four point six times 2 is 109.2 watts. Seven hundred twenty divided by 109.2 is 6.6 hours, if the charger held that watt the whole time, which a lithium charge does not. The sheet’s 6 to 8 hours sits on top of that estimate. A 7 October retailer line said 7 to 8 hours a pack. Six-to-eight and seven-to-eight overlap. They are not the same sentence.

Sixty-five newton-meters, and a speed sensor

The torque cell is 65 newton-meters. It is not labeled EU or international, so this desk will not give the 250-watt version and the 750-watt version each their own 65. The assist sensor is a speed sensor. That is a cadence-style switch, not a torque sensor. A speed sensor does not know how hard you push. It knows that the wheel, or the crank, is moving. The motor page is why a hub watt and a newton-meter are not the same claim. The fork is 100 mm. There is no rear shock. Calling it a mountain bike and a commuter on the same shopping page does not make it a full-suspension e-MTB. The mountain-bike guide is the other category. Tires are 29 by 2.125 inches, front and rear. Two point one two five times 25.4 is 54.0 millimeters. The tire page is the bead. Gears are a Shimano Tourney, 3 by 7, which is 21. Brakes are discs with 160 mm rotors. Hydraulic is written on the C29L brake cells. It is not written on the M cells this desk read. IPX4 is the water line. Max load is 150 kg. One hundred fifty times 2.2 is 330 pounds. The steel rear rack is 25 kg, which is not the 150. Seat height runs from 85 cm to 103 cm. That is 18 cm of drop. Wheelbase is 113 cm. Length is 186 cm, and the millimeter line is 1,860, so that pair agrees.

The scale does not agree with itself

The English cart prints 25.3 kg for the M and 25.5 kg for the L, and another line says 26.5 kg. The French cart says 26.5 kg and does not split M and L. Twenty-five point five times 2.2 is 56.1 pounds. Twenty-six point five times 2.2 is 58.3 pounds. The gap is 1.0 kg, about 2.2 pounds, and it is a printed gap, not a luggage estimate. Climbing is “up to 30°.” Thirty degrees is not 30 percent. The tangent of 30 degrees is 0.58, so the claim, if you convert it, is a 58 percent grade. They printed degrees. Do not shop it as a 30 percent hill. A 7 October dual-battery story repeats 52 km/h, 30 degrees, 90 km per pack, and hydraulic brakes, and it does not mention the EU 250-watt bike or the M’s 45 km/h. That story is the two-pack listing. It is not a correction of the single-pack cart.

Forty-eight times 15 is 720. Twenty-five kilometers an hour and fifty-two are both on the page.

No public film with C29 Pro in the title turned up. A 3 July 2025 upload, 16 minutes, is a year and about 1,800 km on a bike the rider calls the C29. The cart now says the Pro is the upgrade. That film is not this page’s test. A 9 April 2026 ride is also titled C29. Treat both as the older name until someone puts the Pro on the title card. Buy the version whose watt and speed are the ones you are allowed to ride. The €819 is the single pack. The €1,069 is a coupon on a different listing, a week older, for two packs. The 720 watt-hours are the arithmetic the cart left out.