Eunorau 4-Piston Brake Set, 203mm Rotors Review
A 4-piston hydraulic brake set with 203mm rotors, listed at $189 for high-output 750W and 1000W e-bikes and a named list of Eunorau models. The page lists calipers with levers, rotors, adapters and hydraulic lines as the box contents.
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Our verdict
Meant for owners of the listed Eunorau models with the high-output 750W or 1000W setups the page describes, who want a 4-piston hydraulic set with 203mm rotors and motor cut-off sensors in one box. Look elsewhere if the bike is an E-TORQUE, JUMBO, cargo or trike model. The main caveat is that the braking and heat claims are the store's own and the adapter mounts are not named.
- Best for
- Owners of the listed Eunorau models with high-output 750W or 1000W motors who want a 4-piston hydraulic set with 203mm rotors.
- Skip if
- Your bike is an E-TORQUE, JUMBO, cargo or trike model, or you need the mount types and weight stated on the page.
Why 3.5/5: Held back by terms for original parts that leave this brake set unnamed and by the company's BBB profile, which shows an F grade, no accreditation and two unanswered complaints.
Aimed at high-output e-bikes, this 4-piston hydraulic brake set is listed at $189 with 203mm rotors. The page says it is designed for 750W and 1000W bikes, lists integrated motor cut-off sensors and compatibility with SHIMANO D02S/D03S brake pads, and names the Eunorau models it fits. The box is stated as 2x calipers with levers, 2x 203mm rotors, adapters and hydraulic lines of 1050mm/1980mm.
Specifications
| Spec | Page says |
|---|---|
| In the box | 2x 4-Piston Calipers and Levers, 2x 203mm Rotors, Adapters, Hydraulic Lines (1050mm/1980mm) |
| Rotors | 203mm |
| Hydraulic lines | 1050mm/1980mm |
| Brake pads | Compatible with SHIMANO D02S/D03S |
| Motor cut-off | Integrated sensors |
| Designed for | High-output 750W and 1000W eBikes |
Options and pricing
One variant at $189, in stock when read, with no crossed-out price and no size or color choice. The box is listed as 2x 4-Piston Calipers and Levers, 2x 203mm rotors, adapters and hydraulic lines of 1050mm/1980mm. The page does not say which mount types the adapters cover or which pads are fitted.
How it compares
The Eunorau Tektro 4-Piston Hydraulic Brake Set, 203mm Rotor is $299 and its spec line says Post Mount and I.S. mount disc adapters are both included; this $189 set lists 'Adapters' without naming the mounts. The Eunorau 2-Piston 2.0 Hydraulic Brake Set with 180mm Rotors is $119, with 2 piston calipers and 180mm rotors.
Shipping, returns and warranty
Shipping: the shipping page says accessories and batteries go by FedEx or UPS in an estimated 5 to 9 days after 1 to 3 business days of processing; orders over $100 ship free and smaller orders pay $14.99, with a possible remote-area charge. If the local warehouse is out of stock, the item ships from an overseas warehouse in an estimated 10 to 15 business days, and there may be no carrier tracking until it reaches the destination country and clears customs. Returns: an order can be cancelled for a full refund before it ships or is produced, but not after it ships; the page asks buyers not to refuse a delivered e-bike and to contact the store instead. A return must be applied for within 7 calendar days of receipt, the product must be new and re-sellable (not assembled, ridden, used or damaged) and complete with its manuals, accessories and original packaging, and the buyer ships it back within 7 days at their own cost to Eunorau's warehouses in the US, Australia, Europe or the UK. The store inspects it within 5 days and refunds in full when the fault is Eunorau's (wrong, damaged or defective item) or minus the shipping cost when the reason is the customer's. The terms page says customers are charged shipping only once, returns included, with no restocking fee, which does not match the return page's wording. Warranty: the warranty page covers original Eunorau parts and components for 24 months (manufacturing defects only, no labor) but excludes wear items, free gifts and accessories that came with a purchase, and damage from unapproved accessories or chargers; it does not name this item, so ask support whether and how it applies. It is for the original purchaser and excludes shipping damage. Disputes under the warranty go to binding individual arbitration (AAA rules, Nevada law) unless the buyer emails an opt-out within 30 days of purchase.
Before you buy
The page shows 3 customer reviews with 100% of them five-star in the store's own widget, which we could not verify; several product pages show the same review counts or lists, so the figure may not belong to this item alone. Reputation: Eunorau E-Mobility USA Corp has an F grade on the Better Business Bureau, is not BBB accredited and has 2 complaints on file, both marked unanswered: a December 2025 request for proof that a bike sold as new was new, and a May 2025 report of a battery cover that would not latch, which the buyer attributes to a frame defect. A web search on 21 October 2026 found no Trustpilot page for Eunorau. The store says it has specialised in e-bikes since 2009 and designs its bikes in the US and manufactures them in Shanghai, while the BBB lists a business start date of 12 December 2019; the eunorau-ebike.com domain was registered on 27 July 2016.
What we liked
- Box contents are listed: 2x calipers with levers, 2x 203mm rotors, adapters and hydraulic lines of 1050mm/1980mm
- Names a pad match: SHIMANO D02S/D03S
- Gives a long list of Eunorau models it fits and says which types it does not (E-TORQUE, JUMBO, Cargo, Trike)
- Lists integrated motor cut-off sensors
Worth noting
- Claims such as strong, linear stopping power and less brake fade on long descents are the store's own, with no test figures
- Adapters are listed without naming the mount types, and no weight is given
- Power guidance covers only 750W and 1000W bikes; the page says nothing about lower-power models
- Not compatible with E-TORQUE, JUMBO, Cargo or Trike models
Questions before you buy
Which Eunorau models does the set fit?
The page lists D6, DEFENDER, DEFENDER-S, E-FAT-MN, E-FAT-STEP, FAT-HS, FAT-HD, FAT-AWD, the FLASH series, META275, SPECTER-S, SPECTER-ST and UHVO. It says E-TORQUE, JUMBO, Cargo and Trike models are not compatible.
What is in the box?
The page lists 2x 4-Piston Calipers and Levers, 2x 203mm Rotors, Adapters and Hydraulic Lines of 1050mm/1980mm.
Which brake pads fit?
The page says the set is compatible with SHIMANO D02S/D03S brake pads. It does not say which pads are supplied.
How are Eunorau accessories and batteries shipped?
By FedEx or UPS, an estimated 5 to 9 days after 1 to 3 business days of processing; free over $100, otherwise $14.99. If local stock is out, the item ships from an overseas warehouse in an estimated 10 to 15 business days, possibly without tracking until it clears customs.
What is the return window?
The return page gives 7 calendar days from receipt to apply. The item must be new, unused and complete in its original packaging, and the buyer pays the return shipping to Eunorau's warehouse; the refund is full only when the fault is Eunorau's. Orders can be cancelled for free before they ship.
What does the warranty cover?
The warranty page covers original Eunorau parts for 24 months but excludes wear items, free gifts, accessories bundled with a bike and labor, and it does not name this item, so ask support whether it applies.
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
- Eunorau 4-Piston Hydraulic Brake Set with 203mm Rotors product page: specs, options and price (the buy buttons go there)Specs, options and the listed priceRead October 21, 2026
- Eunorau shipping informationFree FedEx/UPS to the lower 48 from Las Vegas; accessories free over $100; overseas-warehouse fallbackRead October 21, 2026
- Eunorau return policyCancel before shipment; 7 calendar days to apply for a return; customer pays return shippingRead October 21, 2026
- Eunorau warranty page (24-Month+ Limited Warranty)Frame 10 years, battery, motor and electronics 24 months; manufacturing defects only; exclusions; arbitrationRead October 21, 2026
- Eunorau FAQClass 1-3 definitions, weight capacity, battery life and charging, design and manufacturing locationsRead October 21, 2026
- Eunorau terms of servicePrices can change without notice; says customers pay shipping once, returns included, and no restocking feeRead October 21, 2026
- Eunorau About pageSays Eunorau has specialised in electric bikes since 2009 and sells in the US, Australia and parts of EuropeRead October 21, 2026
- Eunorau contact pageOrder, customer service and after-sales emails and phone lines; California showroom addressRead October 21, 2026
Independent
- BBB profile: Eunorau E-Mobility USA CorpGrade F, not BBB accredited, 2 complaints in 3 years both unanswered, 1 customer review listedRead October 21, 2026
- BBB complaints: Eunorau E-Mobility USA CorpDec 2025: proof-of-manufacture request unanswered; May 2025: battery cover would not latch, buyer cites a frame defectRead October 21, 2026
- Verisign RDAP record for eunorau-ebike.comDomain registered 2016-07-27Read October 21, 2026
What we couldn’t verify
- The page's claims of strong, linear stopping power, reduced fade on long descents and precision modulation come with no stopping figures or test conditions.
- It lists adapters without naming the mount types, gives no weight, and does not say which pads are supplied, only that SHIMANO D02S/D03S pads are compatible.
- The return page says the buyer pays return shipping, while the terms page says customers are charged shipping only once, returns included, with no restocking fee.
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