Buying a used electric bike: what to check, in order

A used electric bike can be a genuine bargain or an expensive brick, and the difference is almost entirely the battery. Here is what to check, in the order to check it.

We sell new bikes, so treat this as advice from someone with a reason to talk you out of buying used. We have tried to write it as though we did not.

1. Is it legal?

Before anything else. Under UK law an electric bike is an EAPC — an Electrically Assisted Pedal Cycle — if its motor is rated at no more than 250W continuous, assistance cuts out at 15.5mph, and the rider is 14 or over. Meet those and it is legally a bicycle: no licence, no registration, no insurance, no road tax. Check the rating marked on the motor, check the throttle only works to walking pace, and be wary of anything imported directly or described as “derestricted”. If it is not an EAPC you are riding an unregistered, uninsured motor vehicle.

2. The battery, which is most of the value

• Ask for the charge cycle count. Most modern systems store it and a dealer can read it. Under 300 is barely used; over 800 means the pack is near the end of its useful life and you should be pricing a replacement into the deal.
• Ask when it was last fully charged. A bike stored flat for a year may have a pack that will not recover.
• Look at it. Any swelling, any cracked casing, any corrosion on the contacts — walk away. A damaged lithium pack is a fire risk, not a bargain.
• Check a replacement is still sold. Some older or smaller brands no longer supply packs, which turns the bike into scrap the day it fails.

3. Ride it, properly

1. Start from a standstill on the steepest slope available, in the highest assistance mode. This is where a tired motor or a failing torque sensor shows itself.
2. Ride at least a couple of miles and watch the battery gauge. A pack that drops two bars in the first mile is a pack that is lying about its capacity.
3. Listen. Mid-drives hum; they should not grind, tick under load, or change pitch.
4. Cycle through every assistance mode and check the display responds to each.

4. The bits that wear faster on an e-bike

Because torque goes through the drivetrain, these age quicker than on an ordinary bike, and a seller may not have kept up with them:

• Chain: a chain checker costs £10 and settles it in seconds.
• Cassette and chainring: hooked, shark-fin-shaped teeth mean they were run on a worn chain. Add £100–150 to your offer.
• Brake pads and rotors: pads are cheap, scored rotors are not.
• Motor bearings: with the chain off, spin the cranks. Roughness or side-to-side play is a motor service, which is not cheap.

5. Provenance

• Get the frame number and check it on BikeRegister and the police stolen-bike checker. E-bikes are stolen to order.
• Ask for the original receipt. Manufacturer warranties on frames and motors are usually to the original owner only, so understand what you are and are not inheriting.
• Buy from a home address, not a car park. That one rule removes most of the risk.

What it should cost

As a rough guide, an e-bike loses around a third of its value in year one and settles at roughly half after three years — but a pack near the end of its life should take the replacement cost straight off the asking price, because you will be paying it soon — and on a large-capacity pack that is several hundred pounds.