Measure before you order

Identify the exact bike

Record manufacturer, model, model year, frame size, and trim. Find its manual and any component labels. A family name or wheel-size label does not identify every interface. Keep serial numbers in your private records rather than a public build link.

For a hub motor

Use the measurements for the front or rear location you actually intend to use. Compare them with the exact motor drawing.

• Dropout spacing, axle/dropout standard, and the relevant slot or axle dimensions.
• Wheel and tire size, frame/fork clearance, and brake mounting details.
• Rear drivetrain interface and clearance, where applicable.
• Manufacturer requirements for axle retention and torque hardware.

For a mid-drive

Identify the bottom-bracket shell standard and width, then compare the exact motor variant. A product family may cover several widths using different units. Matching shell width is only one check: motor-body clearance, chainline, and installation hardware still matter.

Reserve usable battery space

Measure depth as well as the side outline. Include enclosure, mounts, cable exits, connector access, and the path needed to remove the battery. Check steering, crank, and suspension movement where relevant. A photo is a planning aid; verify critical dimensions on the bike.