Mid-Drive Ebike Conversion Kits
Crank-drive kits for hosts that climb, haul or ride off-road — specified around crank-drive systems, the layout this factory has built since 2011 and the layout of its BBS02/BBS-HD and M400 production models.
The mid-drive is this company's founding technology: its first three years (2011–2014) were spent building inner-rotor mid-drive motors for export to the Netherlands and Japan, prized at the time for low noise, torque and climbing ability. The complete-bike range still reflects that depth, and mid-drive conversion programs are specified against it.
When a Mid-Drive Kit Is the Right Answer
A crank drive multiplies motor torque through the host bike's gears, so it holds pulling power at climbing speed where a hub kit fades; it keeps the wheels light and quick to change; and it centralizes mass at the bottom bracket. The costs are chain wear and a more involved installation. Programs that choose mid-drive kits are usually converting quality hardtails, cargo hosts or fat bikes — exactly the hosts this factory's own BBS02 and BBS-HD production models start from.
Configuration Points
Bottom bracket: the host's BB shell standard decides fitment; measure it before ordering. Power class: follow the host and the market — the 250W class for light city and folding hosts (the class of the M400 production mid-drive), the 750W class as the all-round conversion standard (the BBS02's class in the production fat range), the 1000W class for cargo and off-road hosts (the BBS-HD's class). The exact system is confirmed in the build sheet. Chainline and chainring: specified per host at configuration. Sensors and display: torque-sensing and cadence configurations both exist in the production range; the kit's display and controller are matched as a set. Battery: bundled or separate — see kits with battery.
Questions Buyers Ask
Can I order samples first?
Yes — under the factory's published sample policy, spare units can be provided for sampling; the sample fee and courier cost are paid by the buyer. Confirm availability for the models you want when you inquire.
Will a mid-drive kit fit my existing fleet frames?
Fitment depends on the bottom-bracket standard and clearance of each frame model. Send the frame specification (or the frame itself as a sample) and we will confirm fitment before you commit to volume.
How long does production take?
The published lead time is 30–60 days after the advance payment is received, depending on the product category and order quantity. Ask us to confirm the schedule for the exact models in your inquiry.
What certificates do the products carry?
Certificates available upon request. Send your target market in the inquiry and we will confirm which documentation can be provided for the models you are sourcing.
Before ordering a mid-drive kit, run the host-bike checks in this order. Bottom bracket: measure the shell width and standard, because the motor shaft must match it. Chainline and chainring clearance: check the stay clearance at the ring size you intend to run. Frame material and condition: a mid-drive concentrates torque at the bracket, and a host frame with any doubt at that joint is the wrong host. Brakes: the donor bike's brakes were sized for human power; if they are rim brakes in poor order, budget the brake upgrade into the same project. Ten minutes with a ruler and a torch saves the classic failed conversion.