Builds

This is the conversion bench — the part of the site written from my own knuckles. I converted a donor bike with a Bafang-class mid-drive kit, chose the battery pack with the same Wh math I run on my battery bench, and learned the torque-arm and dropout lessons the hard way so you don’t have to. Every build article in this section traces back to that bike or to the owned bikes it gets compared against.

The honest map for would-be converters: a kit conversion makes sense when you love the donor bike, when you want to understand the machine down to the controller settings, or when the budget genuinely can’t reach a purpose-built mid-drive. It does not make sense as a shortcut to a cheap fast bike — a converted bike still has to comply with your local law, and a drivetrain that wasn’t designed for motor torque will tell you about it in worn chains and chewed cassettes.

Two rules before you order anything: buy the battery as a finished pack from a reputable supplier — cell-level pack building and BMS tinkering are house-fire territory and permanently off this site’s menu — and budget for the unglamorous hardware: torque arm, proper chainline, brake pads rated for the new weight of your ambitions. The build series below documents the rest, mistakes included.