Re: 10 speed
I just built my first motor bicycle on an old 10 speed from the early 70's.
I love it. I used all the stock parts on the bike.
I think the cranks may be wider than modern road bikes have though, and I had to mount the rear sprocket different than the directions said because he rear stays were too narrow for the sprocket and chain.
I am using the stock handle bars (ram horn style), and the throttle works fine on them, but the clutch has to be mounted on the top of the bar, and it is a little awkward to get to in an emergency stop situation, so I am not recommending that. haha I think I will replace them with straight bars soon.
Also it has old style road bike breaks, which don't work so great, so I will be putting modern road bike caliper breaks on it. I will post pics of it soon, but I am having trouble downloading them for some reason tonight.