An eBike conversion kit is the right answer when you have a good bike frame and the wrong answer when you have a cheap one. The motor is rarely the problem; the brakes, wheel and frame you are attaching it to usually are.
What we looked for
- Motor type and placement — hub versus mid-drive, and how each changes handling and hill performance.
- Battery quality and cell provenance, which is the largest cost and the biggest safety variable.
- Installation difficulty and which specialist tools you actually need.
- Brake and frame compatibility, since added speed and weight demand more than a basic bike provides.
Watch the full head-to-head
The ranked picks, the side-by-side comparisons and the ones that did not make the cut are all in the video version of this test.
How to choose
Mid-drive kits use the bike gearing and climb far better, but they load the drivetrain heavily and require more involved fitting. Rear hub kits are simpler, cheaper and perfectly adequate for flat commuting, which is what most conversions end up doing.
Do not economise on the battery. It is the component most likely to cause a fire, the most expensive to replace and the one where unbranded cells of unknown provenance are common. Buy a pack with identifiable cells and proper battery management, even if the kit costs noticeably more.
Common questions
Can any bike be converted?
Most conventional bikes can, but the result is only sensible on a frame with sound brakes and wheels. Carbon frames, very old steel frames and bikes with worn discs are poor candidates.
Is converting cheaper than buying an eBike?
Usually yes on paper, but factor in a battery, possible brake upgrades and your own labour. The saving is real when you start with a good bike and disappears when you do not.