Sounds like what I am after. You over-volt them to get more power/top speed?

My two bikes for this project are 19lbs. I'm hoping to get road bike speed out of the mountain bike, and just more fun out of the road bike.

They both are single speed, so I'm going to have to figure out the best gear ratio. Any ideas? I typically ride on 42x16 gearing (more or less) on the road.

What battery are you using for 90-100 miles?
That hooligan would be a great ebike!

The mountain bike has a std rear drop out size, but the road bike is fixed gear (although SS is obviously possible too). I know they make single speed Q100s, I just have to see if BMS will sell me one (I gotta think in china the vast majority of bikes are single speed).

Yep, you do have an addiction, but I figure for me it is better than throwing $$$ at cars or something more expensive. I used to do all riding on a mountain bike, and just swap the tires for the purpose, but then the expansion started: I needed a reliable commuter bike, a tandem bike, a beater bike, a velodrome bike, etc.