When building a Cruiser/boardtracker styled bike, i did it at an vintage (-54) cycle. Because then i could also use it with an motor, claimed by national laws here in Norway. But to find the old cycle engines arn´t easy here, and the few are pricy, or owners dont wanna sell. Then ist only the lawnmower /chainsaw/weed whacker motors. For me, and my purpose, a chainsaw engine is small enough..(approx 50cc) got one for free... Moods: Because my original crank arn´t wide style, just original 110mm, the width is crucial, to not interfere with the pedals. The hole crank &pedals ar made in one unit, lightly to get ruined when trying to widen it.