DYU C3: 270 Watt-Hours, and 34 km Is 7.9 Wh per km

The DYU C3 is a 14-inch folding electric bike with a chain, a rear rack, and a pack small enough to do the arithmetic in one line. DYU's UK product page prints 36 volts and 7.5 amp-hours. Thirty-six times 7.5 is 270 watt-hours. The chips on that page are a 250-watt motor, 25 km/h, 20 kg, a 120 kg load, disc brakes front and rear, and 34 km of pedal assist against 25 km of "pure electric." Pure electric means the bike moves without you pedaling. That is a throttle, or a mode that acts like one. Twenty-five kilometers an hour is 15.5 mph. It is not a 20 mph Class 2 and it is not a 28 mph Class 3. This desk did not ride it.

Three watt numbers, one pack

Two hundred seventy watt-hours is the whole pack. The Lectric XP Lite3 long-range pack is 672 watt-hours. Two hundred seventy divided by 672 is 0.40. This bike is carrying 40 percent of that pack, on a claimed 20 kg against the Lite3's claimed 49 lb. A 250-watt nominal hub, if the chip is the motor, is the small end of the motor guide. A 500-watt peak, if the reseller sentence is real, is still under the 750-watt federal ceiling. None of that tells you the cadence or the newton-meters. The page does not print torque.

What 34 km actually costs

Thirty-four kilometers is 21.1 miles. Two hundred seventy watt-hours divided by 34 km is 7.9 watt-hours a kilometer, which is 12.8 watt-hours a mile. The pure-electric line, 25 km, is 15.5 miles, and 270 divided by 25 is 10.8 watt-hours a kilometer, or 17.4 watt-hours a mile. AlphaScootz prints the same idea as a band: 20 to 23 miles on pedal assist, 13 to 15 miles on the throttle. Twenty-three miles is 37 km, not 34. Fifteen miles is 24 km, not 25. Close, and not the same sentence. A published loop on the Lite3's 672-watt-hour pack came out at 15.1 watt-hours a mile. At that rate this 270-watt-hour pack is 17.9 miles. That is someone else's loop applied to this pack. It is not a C3 test. The range guide is why a 7.9 watt-hour kilometer is a light rider, a flat road, and a low assist, or it is a brochure.

Thirty-four kilometers on 270 watt-hours is 7.9 watt-hours a kilometer. The page does not say who weighed how much, or which assist, or whether the throttle was off.

The fold does not get shorter

DYU prints the open bike at 1,260 by 485 by 1,040 mm, and the folded bike at 1,260 by 220 by 610 mm. The first number does not change. One thousand two hundred sixty millimeters is 49.6 inches of length whether the hinge is open or shut. What changes is the width, 19.1 inches down to 8.7, and the height, 40.9 inches down to 24.0. A trunk that cannot take 50 inches of length cannot take this fold. A hallway can. Twenty kilograms is 44 pounds, light next to a 70-pound folder and still a two-hand lift up stairs. The folding guide is that split. A May 2026 review reads the card as about 49 by 19 by 40 open and 50 by 8 by 24 folded, and about 44 lb. That matches the millimeters. He also says a 170 lb nominal load. The spec table says 120 kg, which is 265 lb. One hundred seventy pounds is 77 kg. Those are not the same limit. Buy the number on the sticker that ships with the bike.

Class, hill, water, charge

Fifteen and a half miles an hour with pedals and a motor under 750 watts can sit inside the federal low-speed bicycle, 15 U.S.C. § 2085. A throttle that works without pedaling is the Class 2 shape, capped here by the 15.5 mph print rather than by 20. It is not legal in every state just because the federal definition is met. In the EU, an EPAC is pedal assist, 250 watts continuous, cut off at 25 km/h. A pure-electric mode is the part that can push a bike out of that box. AlphaScootz says the model is fully compliant with EU road rules and, on the same page, prints a throttle-mode range. Both sentences are theirs. A US reseller, Damaxed, has listed the same 25 km/h bike at $349.99, sold out, shipping the continental United States. DYU UK has shown £349 against a struck £499, and sold out. Electric Phoenix has shown £419, sold out. AlphaScootz has shown €479, down from €599. Buy the cart. Do not convert those four stickers into one dollar.

The hill line is 15 degrees. The tangent of 15 degrees is 0.27, so that claim is about a 27 percent grade. The page does not say for how many meters, or at what rider weight. A 250-watt chip and a 270-watt-hour pack do not make a long 27 percent climb. IP54 is dust and splashing water. It is not a pressure washer. The cleaning guide is that sentence. Charge time is printed as 3 to 4 hours, at a charge voltage of DC 42 volts, from AC 100 to 220. The table does not print an amp. Seven and a half amp-hours over 4 hours is 1.9 amps if the clock is a full fill, and 2.5 amps if the clock is 3 hours. That is a small brick, not a fast charger. The charging guide is the rest. UL 2849 is not on these pages. The UK warranty line is two years on the frame and one year on the battery and the motor. This desk did not ride it.