Re: whats the largest 2 and 4 stroke motor your willing to intstall in a bicycle ?
I went 60 on my KTM50 before I geared it lower to better utilize the powerband up hills and under normal conditions, I think the biggest I'd go on a beefy bike frame would be a 100cc two stroke or a 200ish cc four stroke, anything over 10HP and its worth just getting a supermoto or a small motorcycle with gears, so you don't have to worry about reliability or things falling apart. With a registered and insured motorcycle you can legally get on the freeway and don't have to worry about confusing drivers with your pedals, or lack of acceleration when stretching out the top speed of a smaller motor. Motorized bicycles and mopeds are awesome within their limitations, I've slapped up against those limitations with the KTM, with the pedals on there, drivers want to do dumb stuff and pass you even if you're going over the posted speed limit.
KTM50 Schwinn Chopper - 6000W E-Motard - 52cc Auger BMX - 9sp+CVT 52cc Cagllari Moped