I have had one motor failure in 1000 miles. I had almost 2kW/hr lipo aboard and I did about 50mph to max of 58mph for about 4 miles without dropping below 40mph ever. Toasted the motor. It was worth it though to find out where it's limit was. The motor I toasted was a stock 130kv wind. With the standard 750 W/hr lipo (in swing arm) I can nearly floor it the entire battery and the motor is hot but below 100C.
I am running the bike on one of my old 80-100 cores right now. Side note the Nuvinci Hub is truly a work of engineering art. It is EXCELLENT!
I have decided this setup needs to be able to sustain 50+ mph with about 3 kW/hr. solution:
going to made into a large can/heat sink. It will have ATF in the bottom and the motor will slosh the oil around. I am hoping not to have to fill the level past 1/3 full time and testing will tell.
This is truly an addicting process once you get something running well. There are so many ways to expand. My roommate just ordered a Rep Rap so expect 3d printed stuff aboard soon!