DYU D3S 14-Inch Folding E-Bike Review
A 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.
Our verdict
Consider it if you want a compact 14-inch folding bike at €499 for short trips and accept figures that come from the store's own page. Look elsewhere if you are tall, expect steep hills or want outside measurements of this exact model: the coverage found is of the earlier D3F, which failed a 12 percent test hill with a 170 lb adult on Electric Bike Report's circuit. The main caveat is that no independent coverage of the D3S itself was found and the page gives both 19kg and 17kg.
- Best for
- Riders who want a small 14-inch folding e-bike for short trips and accept store-supplied figures.
- Skip if
- You are tall, expect steep hills, or want outside measurements of the D3S itself.
Why 3.4/5: Lifted by outside reviews of the earlier D3F and a page that lists motor, battery, weights, folded and full sizes and box contents; held back by two weights on the page, by no review found of the D3S itself, and by the store terms and reputation notes below.
The D3S is a 14-inch mini folding e-bike listed at €499. Its spec list gives a 250W motor, a 36V 10Ah battery, a 25km/h top speed, 50km of assisted range and 19kg net weight, and the page headline says 'No Throttle'. The outside coverage found is all of the earlier D3F, the same 14-inch bike under its original name, which had a twist throttle. On the D3F, Electric Bike Report measured an average of 13.6 mph on pedal assist and one 29.65-mile range test, and called it mostly a toy while allowing it may suit affordable transportation.
Specifications
| Spec | Page says |
|---|---|
| Motor | 250W |
| Battery | 36V 10Ah |
| Net weight | 19kg |
| Max load | 120kg |
| Max speed | 25km/h |
| Assistant-Mileage | 50km |
| Frame | Metal |
| Full size | 1170 x 500 x 990 mm |
| Folded size | 1170 x 200 x 720 mm |
| Brake mode | Front and rear disc brakes |
| Charging time | 5-6 Hours |
| Lights | Yes, headlight & rear fog light |
| Recommended height | 5.24-6.39 FT |
| IP rating | IP54, per the page |
Options and pricing
The page lists one variant: black with an EU plug at €499, shown with a crossed-out price of €749. Its box list names the bike, two pedals, a charger, instructions, a hexagon spanner, a 15mm single open wrench and a fender, with a child seat as an optional item. The page also says front and rear baskets can be fitted as needed.
How it compares
The DYU C2 16-Inch Full Folding Electric Bike costs €549 and is a 16-inch folding bike with a magnesium frame, but its page lists three weights (22.5kg, 23.6 kg and 29.6kg); this D3S, at €499, is a 14-inch bike with 19kg on its spec list. The DYU T1 20-Inch Foldable Electric Bike is €699 and is a 20-inch folding bike with a magnesium frame, a torque sensor and 22.5kg, and its page claims 60km against the 50km on this page.
Shipping, returns and warranty
Where it sells: the shipping page names these EU countries: Austria, Belgium, Bulgaria, Croatia, Czechia, Denmark, Estonia, Finland, France, Greece, Hungary, Ireland, Italy, Latvia, Lithuania, Luxembourg, the Netherlands, Poland, Portugal, Romania, Slovakia, Slovenia, Spain and Sweden (Croatia appears twice); Germany is not on the list, and a cart test on 22 October 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. Prices are in euros. Shipping: free over EUR 100, an estimated 3 to 5 business days, shipped within 2 working days from a Poland or German warehouse by FedEx, UPS or DPD (the FAQ page says 2 to 7 business days, and the Terms of Service say delivery 'may take up to 50 days'). Returns: 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 the buyer pays 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 FAQ on this product page says 14 days, and the Terms of Service describe a 7-day dead-on-arrival rule, 10 days for faulty goods and 30 days for unopened items. Warranty: the warranty page gives one year from delivery for manufacturing defects: a replacement frame only (no labor), a battery repaired or replaced in year one and then a prorated credit, tires, brake pads and chains excluded, and claims by email to [email protected] with photos or video; product pages show a '12-24 Months Warranty' banner.
Before you buy
The page shows 533 customer reviews with 77% of them five-star in the store's own widget, which we could not verify. Reputation: Trustpilot lists dyucycle.com with a TrustScore of 3.7 from 209 reviews (60% five-star, 26% one-star), a profile claimed in June 2024 with a Dover, Delaware address, and says the company replies to negative reviews. Recent one-star reviews describe bikes cutting out while riding, requests for EUR 100 to 200 return fees, unanswered emails and, from a Dutch reviewer, a model that was not road legal in the Netherlands; we have not verified any of them. The registry shows dyucycle.com registered on 8 April 2021. The About page says DYU was founded in 2016 and sells in over 60 countries, which we could not confirm; the Terms of Service are governed by the laws of Hong Kong, while the contact page gives a Rotterdam office address. The page shows a crossed-out price of €749 next to its '60-Day Lowest Price Guarantee' banner; that is the store's own comparison figure. The store lists this bike twice at the same price under two page addresses with near-identical text; this review covers both.
What we liked
- The spec list gives a 250W motor, a 36V 10Ah battery, a 25km/h top speed and 19kg net weight
- Folded size is listed as 1170 x 200 x 720 mm, and the page describes a three-step fold
- Front and rear disc brakes, a headlight with a rear light and an LCD battery display are listed
- Independent measurements exist for the earlier D3F: Electric Bike Report measured speeds, a range and a stopping distance
- The box list is detailed: pedals, charger, spanner, wrench and a fender, with an optional child seat
Worth noting
- All outside coverage found is of the earlier D3F, not the D3S; the D3F reviewed had a twist throttle where this page's headline says 'No Throttle'
- Electric Bike Report: the D3F failed a 12 percent test hill twice with a 170 lb adult (a 10-year-old cleared it), and its brake levers arrived reversed
- BikeRide reports a non-removable battery on the D3F and judged its hill climb inadequate; its range test was 22.03 miles, mostly on the throttle, with 728 ft of climbing
- TechStage (2020, unit supplied by the retailer Banggood) found the D3F's support weak, its motor weaker on a gradient of a few percent, and the bike not fully foldable
- A 6 ft rider (BikeRide) and riders over 1.70 m (TechStage) were cramped on the D3F, while this page lists a recommended height of 5.24-6.39 FT
- The page gives 19KG in several places but 17KG under 'Bicycle Weight' in its product details
Questions before you buy
What battery and motor does the D3S list?
The spec list gives a 250W motor and a 36V 10Ah battery; the technical table adds a lithium-ion battery with a BMS, a DC42V charging voltage and a 5-6 hour charge time. The page says the motor can reach 500W at its peak. It does not say whether the battery can be taken off the bike; BikeRide reports a non-removable battery on the earlier D3F.
How big is it folded, and how heavy?
The spec list gives 1170 x 200 x 720 mm folded, 1170 x 500 x 990 mm at full size and 19kg net weight, with a max load of 120kg. One line of the product details says 17kg instead. The page describes a three-step fold and says the bike can be carried on a subway or put in a car trunk.
Is there an independent review of the D3S?
None found for the D3S itself. The three outside reviews found are of the earlier D3F: Electric Bike Report (published Jan 2023, updated Jun 2024), BikeRide (read from a Nov 2025 archive copy) and TechStage (28 Aug 2020, a unit supplied by the retailer Banggood). All three report weak hill performance, and none mentions the D3S.
Does DYU ship to my country?
The shipping page names 24 EU countries and prices are in euros. A cart test on 22 October 2026 gave free delivery in an estimated 3 to 5 business days for French, Spanish and Italian addresses and no shipping rate for German, UK, US, Swiss, Norwegian or Vietnamese addresses. Ask [email protected] before ordering from anywhere else.
What is the return window and what does it cost?
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 is deducted (EUR 100 per battery). The FAQ on this product page says 14 days and the Terms of Service describe 7, 10 and 30-day rules, so get the terms that apply to your order in writing.
What warranty does a DYU bike carry?
The warranty page gives one year from delivery for manufacturing defects: a replacement frame only, a battery repaired or replaced in year one and then a prorated credit, and claims by email with photos or video. Product pages show a '12-24 Months Warranty' banner that the page does not explain.
Sources & verification
What this review is based on and the day we last read it. Specs and claims from the maker are the maker’s own; the verdict and the rating are ours.
From the store
- DYU D3S 14-Inch Mini Folding Electric Bike product page: specs, options and price (the buy buttons go there)Specs, options and the listed priceRead October 22, 2026
- DYU shipping and delivery page24 EU countries named, free over EUR 100, 3-5 business days, shipped from a Poland or German warehouseRead October 22, 2026
- DYU return and refund policy page30 days; EUR 200 per bike deducted for a change of mind; EUR 100 fee on quality returns; 5% fee when cancelling before shipmentRead October 22, 2026
- DYU warranty page1-year limited warranty: frame replacement only, battery 1 year then prorated credit, claims by email with photos or videoRead October 22, 2026
- DYU Terms of ServiceStore operated by 'dyucycle'; governed by the laws of HK; its return section (7, 10 and 30 days) differs from the return pageRead October 22, 2026
- DYU FAQ pageDelivery in 2-7 business days by FedEx, UPS or DPD; order changes before dispatchRead October 22, 2026
- DYU contact page[email protected]; office address Shannonweg 40, 3197 LG Botlek, Rotterdam, NetherlandsRead October 22, 2026
- DYU About pageMilestones as the store states them (founded 2016, Costco in the US 2018, 60+ countries); not independently confirmedRead October 22, 2026
- DYU D3S second listing (same bike, older page address)Near-identical text and the same price as the main listingRead October 22, 2026
Independent
- Trustpilot profile for dyucycle.comTrustScore 3.7 from 209 reviews, 60% five-star, 26% one-star; claimed profile; Dover, Delaware address shownRead October 22, 2026
- Verisign RDAP record for dyucycle.comDomain registration date (see the 'Before you buy' section)Read October 22, 2026
- Electric Bike Report: DYU D3F review (the earlier version of the D3S)Test of the earlier D3F: 13.6 mph average on assist, a 29.65-mile range test, failed a 12% hill with an adult; verdict 'mostly a toy'Read October 22, 2026
- BikeRide: DYU D3F expert review (the earlier version of the D3S)Throttle-mostly range test of 22.03 miles; hill climb judged inadequate; reversed brake levers; read from a Wayback Machine copyRead October 22, 2026
- TechStage (heise): DYU D3F test, 2020 (the earlier version; unit supplied by Banggood)2020 D3F with a fixed 250 Wh battery and twist throttle: about 30 km with pedal support, 15 km on throttle; no road approval in GermanyRead October 22, 2026
What we couldn’t verify
- The page gives 19KG in its header, spec list and technical table but 17KG under 'Bicycle Weight' in the product details; the spec list says 50km assisted range while another block says 30-37 miles per charge.
- All outside coverage found is of the earlier D3F, a 14-inch bike under its original name, and none mentions the D3S; the D3F reviewed had a twist throttle while this page's headline says 'No Throttle'.
- The headline calls the bike '100% EU Street Legal'; the page names no standard or test behind it, and it does not say whether the battery is removable.
- The store's pages disagree on returns: 30 days on the return page, 14 days in this page's FAQ, and 7, 10 and 30-day rules in the Terms of Service; the return page deducts EUR 200 per e-bike for a change of mind.
- Product pages show a '12-24 Months Warranty' banner while the warranty page gives one year for manufacturing defects.
Spotted an error or something out of date? Tell us and we’ll fix it and update the date.
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