Chinese e-bike conversion kit: what to check
Check the exact battery, charger and drive-system combination, your bicycle’s condition and the installer’s competence before fitting. Confirm the finished bike meets road-use rules. Government guidance says private installers also carry safety responsibility. Supplier evidence can be checked in China by Cambridge China Bridge.
Specify the complete combination before ordering
Ask the supplier to identify the motor, controller, battery and charger by exact model, with instructions and a declaration of conformity for the supplied kit. Request written confirmation that these components are intended to work together. Matching plugs or advertised voltage alone should not be your acceptance test.
Compare the documents with photographs of the actual component labels. Check that test reports cover the supplied configuration using our guide to verifying product test reports. Keep general supplier capability checks separate, using the factory audit checklist.
Resolve battery and charger compatibility
For replacement batteries or chargers, government guidance advises using genuine items authorised by the cycle or drive-system manufacturer. Ask who authorises the proposed combination and request the supporting documents. If the supplier cannot establish compatibility, stop the purchase rather than trying adapters or modifying connections.
Record battery voltage, charger output, connector polarity and the controller’s permitted operating range from the manufacturer’s documents. Ask the installer to review them together. Our battery sourcing guide covers the wider procurement questions; this check concerns the combination fitted to your bicycle.
Assess the bicycle and agree the installation
Have the installer inspect the frame, forks, wheel fixings, brakes and battery mounting position before you order. Ask them to confirm the bicycle can accommodate the proposed conversion, explain any necessary repairs and identify reasons they would refuse the job.
Government guidance recommends a competent professional with insurance covering this work where possible. Ask about experience with the proposed kit and confirm conversion work is covered. Agree a handover record covering component identities, secure mounting, cable routing, braking and assistance operation.
Check the finished bike’s road-use status
For Great Britain, check that the pedals can propel the bicycle, maximum continuous rated motor power does not exceed 250 watts and assistance cuts off at 15.5 miles per hour. Ask for continuous rated power rather than relying on a peak-power advert. Confirm these points for the finished conversion.
If the bike fails the electrically assisted pedal cycle rules, it is classed as a motorcycle or moped. Throttle propulsion without pedalling can also trigger vehicle approval requirements, with an exception for low-speed walk assistance. Have the installer establish the intended configuration’s status before road use.
Keep responsibility and charging arrangements clear
Government battery guidance says the installer is liable for the product’s safety even when acting as a private individual. Treat fitting your own kit as a safety responsibility. Keep the supplier correspondence, instructions and installation record, and resolve unanswered safety questions before using it.
Plan a charging location clear of escape routes. Follow the manufacturer’s instructions and charge while awake and present. Agree who handles compatibility questions, replacement parts and faults after installation, so a future battery or charger replacement receives the same review.
Frequently asked questions
Can I use my existing battery with a conversion kit?
Ask the drive-system manufacturer to authorise the exact battery and charger combination. Matching voltage or connectors alone is insufficient grounds to approve it.
Can I fit an e-bike conversion kit myself?
Government guidance says private installers are liable for product safety. It recommends a competent professional insured for conversion work where possible.
Is a Chinese e-bike conversion kit road legal?
Origin does not establish road legality. Check the finished bicycle’s pedals, continuous rated motor power, assistance cut-off and any vehicle approval needed for throttle operation.
What should I ask the factory before buying?
Request exact component models, compatibility confirmation, instructions, a declaration of conformity and relevant test reports. Have the proposed installer review the pack before ordering.