Hi I have an old trek road bike that I would like to convert to an e bike. I am a fit 90kg rider but I am recovering from treatment and need some help to keep up with my mates up the hills. I am looking for something with minimal drag on the flats. Just assistance up the steep stuff..Road bike is a 10 year old trek 10 speed cassette. Bottom bracket 68mm width. 35mm diameter. Ideally like torque sensor to give it a more realistic feel. Any suggestions?