I got the wide crank but the engine and reduction unit was still too wide so I ended up heating and bending the wide crank even wider. The Gasbike $199 kit is slightly over ten inches wide. Unfortunately the wide crank didn't come with a chainwheel. The wide crank takes a hex hole in the chainwheel while the original Schwinn crank needs a round center hole and another for the drive pin. I did it the hard way,drew out the hex on the wheel and hand filed it out. With half an hour of filing the chainwheel fit the crank. I installed the 44 tooth sprocket to replace the 50 tooth. The bike still starts out from a standing start well so I could probably could have gone down to a 40T. I might try one later because the engine still sounds like it's turning a lot faster than it needs to. Still have a good bit of vibes to tame. I was quite surprised that this set up has so much more vibration and noise than my two stroke bike.