Solo e-bike conversion

Fitting a Bafang to a solo ‘should’ be straightforward, but my Qubic steel framed MTB threw up a couple of issues.
I bought the motor and battery separately through AliExpress. There are dozens of suppliers, many based in China but a lot of sellers now have the option of buying from a distributor in the UK or EU, which makes delivery times a bit faster, though you will probably pay more for these options. I opted for a German source and it took about 10 days for delivery, but there was a German bank holiday at the time of order which delayed dispatch.

I chose a 15Ah battery with USB outlet and the 250W motor kit (UK street legal limit). As I have hydraulic brakes on the Qubic I also sourced brake sensors from Amazon. I used a UK supplier so they cost more but I wanted a faster delivery.

The hydraulic brake sensor consists of a small magnet that can be superglued or bonded to the lever and the sensor unit that attaches to the brake housing. They come with self adhesive pads, but I used Sugru ‘putty’ glue to ensure they stayed put.
The battery with on/off switch, recharging port, lock to prevent removal from bracket and the USB port. For a 15Ah battery, the housing is quite large – bigger than the 17.5Ah on the Pino.
A Bafang kit and battery – this one went onto my trike but the contents of the kit are the same.

First job is to remove the bottom bracket on the bike. I had a Shimano Hollowtech with external bearings, so this was very straightforward. The motor slides into the BB shell and is locked in place by a castellated lock-ring.

The motor in-situ. I had to add spacers to move the motor out further on the drive-side as fully pushed home it was contacting the chain stay. I used some spacers from the old BB on the drive side and a couple of spacers in the clamps on the non-drive side.
The spacers on the clamp to move the motor more to the drive side. There was still plenty of thread for the locking ring on the BB.

My other issue was that the bottle-cage fixings did not align with the battery bracket, so I bought three brackets from eBay. These elevated the bracket from the downtube and reduce the space for the battery. It’s a tight fit.

The kit and battery fitted onto the bike. The battery is large for a 15AH and only just fits in the available space. There’s a millimetre between the seat tube and the battery and just enough space below the cross bar to allow removal of the battery.
The battery mounting bracket in place. At some stage I will re-route the gear cables as the brackets are too close to the cable guides on the frame.
One of the three clamps used to fit the battery bracket. I had to drill a hole in the bracket to fit this in place. You can see the bottle cage mounts on the frame, which did not align with the mounting points on the bracket. I looped the excess control wire under the battery bracket to keep the job a bit tidier.
The thumb throttle and control pad. Strictly the throttle is illegal, as it can power the bike independently of pedalling but I find it very useful for pulling away at junctions or to get the bike moving on hill-starts.
The control display. Connections are pretty fool-proof as they are colour coded male-female type connectors. The display can be metric or imperial and shows typical trip computer information like odometer, trip distance, average and maximum speeds.