My hub motor, Kelly controller, throttle, and speed display arrived. The first thing I had to do was work out where to source a tyre from, and how to get it on the rim of the hub motor. Fortunately for me, the awesome folks over at Brisbane Motorcycles put a tyre on the hub motor, even though they had never seen one before.
Once the tyre was installed on the hub motor, I had to get the whole thing attached to the bike. It turns out the rear swingarm was built out of hollow aluminium channel. This means it’s quite wide and the axle of the hub motor was too short to fit all the way through. As a result, I had to cut a section out so that I could attach the bolts through one side of the aluminium channel. This worked pretty well, and shouldn’t affect the mechanical strength much. If the engineer (to sign off the roadworthy) disagrees, I can always add some reinforcement around it.
Once the cuts were made, the wheel had to be moved into place. This was a lot more challenging than I had anticipated due to the weight of the wheel. I ended up using an overhead crane/hoist in the workshop to lift the bike up slightly so that it was easier to line up. The final thing left to do for the wheel attachment is to mark out and drill some holes; to bolt in the torque arms on each side.
Once the motor was semi-attached (minus the torque arms) to the swingarm, it was time to do some HV wiring. Even though I’m “only” dealing with 100v here, it can still cause harm, and adequate precautions were taken. The wires from the motor were basically the perfect size, so they were bolted straight into the appropriate spots on the motor controller. Unfortunately, the motor controller ended up being way bigger than I thought it would be. Instead of bolted to the back of the battery cage, I had to make a small frame and mount it up underneath the seat. On the plus side, it should be easier to direct a little air across it here for better cooling.
Next up is the throttle control. I had to pull off the old handle bar grips (which was quite a challenge!) and slide on the new ones. The supplier accidentally shipped me two right hand grip/button assemblies, so I just left the original left hand one on there and replaced the rubber grip. Once the new grips and button assembly was installed, I wired up the throttle to the motor controller. The motor controller came with all the connectors and and inserts ready to be crimped, which was nice.
Initially, the motor setup guide was confusing to follow. Eventually I worked out that I had to change the “Identification Angle” item in the settings to 170 and reboot the controller, even though it had already “successfully” showed 85. This is because the controllers are tested in the factory, so you need to reset this value, and let the controller recalibrate to the motor it’s connected to.
Once the controller had been “recalibrated” to the new motor, and the throttle hooked up, it was time to do a spin test of the motor. I made sure the bench power supply I was using (I found one that went all the way up to 100v!) had a low current limit set just in case. I then jacked up the rear of the bike using the car jack from my Nissan Leaf (pictured in the background below). Once it was jacked up, I was ready to give the throttle a twist. I slowly ramped up to full speed and recorded a video you can watch below. I was pretty excited to see everything running smoothly at this point! The torque arms are not attached yet, so it slips slightly at the start, and that’s the clunk sound you can hear.
I would call that a pretty successful test! The motor spun up and down a few times very reliably and sounded awesome while doing it. The bright orange HV cable also arrived, along with the cable lugs and hydraulic crimper for them. This will be useful in a few weeks when I finished building the battery pack and need to hook it up to the motor controller.
That’s all for now! Stay tuned for the low voltage system (aka the 12v system) that will run all of the lights, indicators, BMS, contractor, etc. I’m currently in the middle of hooking it all up and will be posting about it shortly.
