The bike I am working on isn't motorized yet. I'm just starting on it. And I don't have to shorten the chain now, anyway, I found another solution. I didn't really want to do that, anyway. I installed the wide crankset conversion from a one piece crank. The only thing is it came with a 36T, when I had a 44T. I drilled some holes in the 36T, and bolted a 44T onto it, fixed. The 36T would have been way too low, it's geared low enough with the 44T.