@ Fietsbel: I just got another twist throttle, I just read your offer but it was too late! thanks anyway. I managed to create a new mini drive system like yours (commuter booster), from some scrap HMPE block, and with some sawing and drilling it turned out to be a great clamp! I just tested it with a 5065 motor and got 9.9Wh/km going 38-42 km/h! Thats more than 10 % better than my heavier 6374 kepler drive proto. The whole drive+motor+ESC+electronics weighs less than 1 kg. Now I have 2 fully functional e-bikes!! I want to make more of them to share the fun! My girlfriend would love one for sure, although I will probably use a 4S setup or just 3S to keep her riding around at safe speeds. I'm thinking of building one on a light foldable bike. +- 30km/h is a great speed for normal short/medium range use.
I am also going to test the drive at lower speeds and see what Wh/km I can get out of it, now a 1050g 5S 8Ah battery lasts for 15 km.
Have you found a better solution to the sanding belt/grip tape? I am using grit 40 sanding belt, and it grips really really well, even in sandy/wet conditions, but it also eats a lot of rubber. Riding my big 6374 edrive once every week to work and back (65km total), I have done 245 km with a brand new expensive Schwalbe Marathon Plus and it already looks like 30% is gone. That would account for 5 cents/km!! which is a lot compared to the electricity costs: 0.17 cents/km! So that needs to be solved. I was thinking of a metal sleeve around the motor with a knurled pattern in it. The un-even grit on the grip tape seems to be the main cause of wear.
