Folding e-bikes from DYU, compared by wheel size, motor, battery, folded size and price.
DYU T1 20-Inch Foldable Electric Bike — read reviewA 20-inch foldable e-bike with a magnesium alloy frame, a 250W motor, a torque sensor and a removable 36V 10Ah battery, listed at €699. It suits riders who want larger wheels in a folding bike and accept store-supplied range and weight figures.
DYU D3S 14-Inch Folding E-Bike — read reviewA 14-inch folding e-bike listed at €499, with a 250W motor, a 36V 10Ah battery and 19kg on the spec list. It suits riders who want a small bike for short trips; the outside coverage found is of the earlier D3F, not this D3S.
DYU C2 16-Inch Folding E-Bike — read reviewA 16-inch folding e-bike with a magnesium alloy frame and a 250W motor, listed at €549. It suits riders who want a small folding commuter with a rear rack and can accept a page that gives three weights, two batteries and two ranges.
DYU C9 20-Inch Long-Range Electric Bike — read reviewA 20-inch fat-tire folding e-bike with an aluminium alloy frame, a 250W motor and a removable 48V 15.6Ah battery, listed at €999. It suits riders who want fat tires and a large battery; the outside coverage found is of a different US-market C9.
DYU SP1 20-Inch Power Bank Folding E-Bike — read reviewA 20-inch aluminum-frame folding e-bike with a 250W motor and a removable 24V 5Ah battery that the page says supports mobile device charging, from €1,099. The page states no range and gives no weight with the battery fitted.
The 5 folding e-bikes here all come from one store, DYU (dyucycle.com), which prices in euros and ships only to a list of EU countries. They run from €499 for the D3S 14-inch to €1,099 for the SP1 ("from" price), with the C2 at €549, the T1 at €699 and the C9 at €999, as checked on Oct 22, 2026. Compare size and weight first, because a folding bike has to be carried. Wheels are 14, 16 or 20 inches; the weights listed run from 14 kg for the SP1 (without fenders and battery) to 30 kg for the C9; and the folded sizes run from 700 x 450 x 620 mm (SP1) to 1170 x 200 x 720 mm (D3S). The C2 page gives three weights, 22.5, 23.6 and 29.6 kg, and the D3S page gives 19 kg and 17 kg, so read the spec list and confirm with the store.
All five list a 250W rated motor, and the D3S and C2 pages say peak power can reach 500W, so battery size and range claims are what differ. Volts times amp-hours gives watt-hours (Wh), the energy a battery stores: 36V 10Ah is 360 Wh (D3S, T1 and the C2 spec list), the C9's 48V 15.6Ah is about 749 Wh and the SP1's 24V 5Ah is 120 Wh. Four pages list 25 km/h as the top or rated speed; the SP1 lists assist fading from 10 to 24 km/h. Ranges are the store's own: 50 km (D3S), 60 km (T1), 60 km on the C2 spec list but 40 km in its header, and 150 km in pedal assist for the C9, with no test method; the SP1 page states none. The D3S headline says 'No Throttle', while the coverage found is of its earlier D3F, which had a twist throttle.
Every review here comes from DYU, so these are its terms. The shipping page names 24 EU countries, not Germany, and a cart test on Oct 22, 2026 returned no shipping rate for a German, UK, US, Swiss or Norwegian address; delivery is free over EUR 100 from a Poland or German warehouse, an estimated 3 to 5 business days, although the FAQ says 2 to 7 and the Terms of Service say it may take up to 50 days. The return page gives 30 days for a bike in its original packaging with under 10 km on the display; for a change of mind you pay the return and EUR 200 per e-bike (EUR 100 per battery) is deducted. The D3S FAQ says 14 days, and the Terms of Service give 7, 10 and 30-day rules. The warranty page gives one year for manufacturing defects, with a replacement frame only, while product pages show a '12-24 Months Warranty' banner.
Trustpilot lists dyucycle.com at 3.7 from 209 reviews (60% five-star, 26% one-star); recent one-star reviews describe bikes cutting out while riding, EUR 100 to 200 return fees and unanswered emails, and we have not verified them. A Dutch reviewer said a model was not road legal in the Netherlands, and the D3S headline says '100% EU Street Legal' without naming a standard. The Terms of Service are governed by Hong Kong law, while the contact page gives a Rotterdam address. Look elsewhere if you live outside the 24 listed countries or need a clear return rule before paying.
| Review | Price | Wheels and frame | Battery | Weight | Folded size |
|---|---|---|---|---|---|
| DYU T1 20-Inch Foldable Electric Bike | €699 | 20-inch wheels; magnesium alloy frame, per the page | 36V 10Ah, removable with a key per the page; 18650 lithium-ion type | 22.5kg per the spec list; 23KG in the technical table | 885 x 445 x 875 mm, per the technical table |
| DYU D3S 14-Inch Folding E-Bike | €499 | 14-inch wheels; metal frame per the spec list | 36V 10Ah, per the spec list | 19kg on the spec list; 17kg in one product details line | 1170 x 200 x 720 mm, per the spec list |
| DYU C2 16-Inch Folding E-Bike | €549 | 16-inch wheels with 16 x 2.5-inch tires, per the page | 36V 10Ah per the spec list; the header says 48V 7.5Ah | 22.5kg per the spec list; 23.6 kg and 29.6kg elsewhere | — |
| DYU C9 20-Inch Long-Range Electric Bike | €999 | 20 x 3.0-inch fat tires on 20-inch hubs, per the page | 48V 15.6Ah, removable and anti-theft per the page | 30kg on the spec list | 970 x 465 x 760mm, per the spec list |
| DYU SP1 20-Inch Power Bank Folding E-Bike | From €1,099 | 20-inch; aluminum alloy frame with 3D forging per the page | Removable LG 24V 5Ah; single or dual battery style | 14 kg excluding fenders and battery, per the spec list | 700 x 450 x 620 mm, per the spec list |
DYU lists a folded size on four of the five pages: 700 x 450 x 620 mm for the SP1, 885 x 445 x 875 mm for the T1, 970 x 465 x 760 mm for the C9 and 1170 x 200 x 720 mm for the D3S. At least two pages disagree with themselves: one calls 885 x 445 x 875 mm the full size in its spec list and the foldable size in its technical table, and another gives different sizes in its spec list and its technical table. Confirm the folded size with the store before checking it against a car boot or a flat.
The spec lists give 19 kg (D3S), 22.5 kg (C2 and T1), 30 kg (C9) and 14 kg for the SP1 without fenders and battery, for which the page gives no weight with the battery. The pages disagree with themselves: the D3S says 17 kg in one line, the T1 says 23 kg in its technical table, and the C2 says 23.6 kg and 29.6 kg elsewhere.
Multiply volts by amp-hours. The D3S, T1 and C2 spec list give 36V 10Ah, which is 360 Wh; the C2 header's 48V 7.5Ah also works out to 360 Wh. The C9 lists 48V 15.6Ah, about 749 Wh, and the SP1 a removable LG 24V 5Ah, 120 Wh. One outside reviewer notes that the SP1's 120 Wh is above the 100 Wh airline carry-on threshold, although the page says the bike is fully compliant for airline travel.
The shipping page names 24 EU countries and prices are in euros. Germany is not on the list, and a cart test on Oct 22, 2026 returned no shipping rate for a German, UK, US, Swiss, Norwegian or Vietnamese address, while French, Spanish and Italian addresses got free delivery in an estimated 3 to 5 business days.
The return page gives 30 days for a bike in its original packaging with under 10 km on the display. For a change of mind you pay the return and EUR 200 per e-bike (EUR 100 per battery) is deducted; a defective bike is exchanged or refunded within 30 days, and cancelling before shipment costs 5%. The D3S FAQ says 14 days and the Terms of Service describe 7, 10 and 30-day rules, so ask which applies before you order.
The warranty page gives one year from delivery for manufacturing defects: a replacement frame only, with no labor, and a battery repaired or replaced in year one and then a prorated credit. Tires, brake pads and chains are excluded, and claims go by email with photos or video. Product pages show a '12-24 Months Warranty' banner, which does not match.