I decided a few months ago to build an e-bike using a pretty good second hand MTB as a base. It's been something of a trial. Just about everything has to be built and unbuilt a half dozen times to meet my exacting requirements. This is ongoing as everything has to work well and be as easy to service as I can make it. And I'm learning more about it all the time. Being a selfish sort of prick, I went for the biggest badest thing I could afford, which was a (supposedly) 1500W hub motor, with a 20A battery to match. My initial thought was, "Oh yeah, I'll definitely be wanting the hand throttle". On the first test, a couple of problems became apparent. Firstly, the pathetic MTB gearing runs out way before the motor runs out of legs. It's pointless even pretending to pedal, and attracts unwanted attention. Secondly, the power delivery is super abrupt. Full throttle is no more than 1/4 turn and the sensation is very much all or nothing. Feathering the throttle delicately requires virtually superhuman control. Thirdly, it's way too busy on the right grip. I've had to swivel the gear selector down to a really awkward angle in order to clear everything. Furthermore, since top gear is selected virtually all of the time, when you find that you have to pull up on a steep uphill, it's impossible to make the necessary downshifts before halting without dropping the throttle altogether. This is a really s*it sensation.
I'll try a freewheel with a 13 tooth top gear, and try fitting my road crankset to see if this is sufficient to solve the gearing problem, although a big chainring might not clear the stays. But really, I've had to reconsider the whole thing. The first thing I want to try out is the PAS system in order to tame the power delivery somewhat. I could limit the output to 250W by simply joining a pair of wires provided for the purpose. I'm not sure if connecting the PAS has the same effect. Guess I'll find that out soon enough. On the plus side, it would serve the purpose for which it was intended, to make cycling easier. On the other hand, sometimes I just enjoy going like stink. But doing this makes it blatantly obvious that it's really a motorised vehicle, so I'm preparing it for actual registration. Doing this might help me out in the event of a stack too.
What I'm thinking that I'd like to try, if it's possible, is to fit the PAS while retaining either the twist, or fitting a thumb throttle. I'd like it to be either tame or wild as required. 250W might be OK if that's all you've got. But leaving the best part of what's available on the floor doesn't have a lot of appeal. Any useful advice in this regard would be appreciated.
I'll try a freewheel with a 13 tooth top gear, and try fitting my road crankset to see if this is sufficient to solve the gearing problem, although a big chainring might not clear the stays. But really, I've had to reconsider the whole thing. The first thing I want to try out is the PAS system in order to tame the power delivery somewhat. I could limit the output to 250W by simply joining a pair of wires provided for the purpose. I'm not sure if connecting the PAS has the same effect. Guess I'll find that out soon enough. On the plus side, it would serve the purpose for which it was intended, to make cycling easier. On the other hand, sometimes I just enjoy going like stink. But doing this makes it blatantly obvious that it's really a motorised vehicle, so I'm preparing it for actual registration. Doing this might help me out in the event of a stack too.
What I'm thinking that I'd like to try, if it's possible, is to fit the PAS while retaining either the twist, or fitting a thumb throttle. I'd like it to be either tame or wild as required. 250W might be OK if that's all you've got. But leaving the best part of what's available on the floor doesn't have a lot of appeal. Any useful advice in this regard would be appreciated.