Who runs a 20" rear hub?

[izeman]

depending on the make of your cranks you may be able to shorten them. unfortunately all newer ones i know of or hollow. so you can't do it.
preferably you need a mill and pedal thread cutters. but you can just cut off the crank, drill a hole and cut the threads (thread cutters can be found for $20 at amazon). just take care that you drill the crank 100,0% perpendicular or your pedals will not run straight.
see this german site (i guess the pictures will make it clear and google translate will do the rest) http://www.enhydralutris.de/Fahrrad/Kurbelkuerzen/index.html

 

[John Bozi]

depending on the make of your cranks you may be able to shorten them. unfortunately all newer ones i know of or hollow. so you can't do it.
preferably you need a mill and pedal thread cutters. but you can just cut off the crank, drill a hole and cut the threads (thread cutters can be found for $20 at amazon). just take care that you drill the crank 100,0% perpendicular or your pedals will not run straight.
see this german site (i guess the pictures will make it clear and google translate will do the rest) http://www.enhydralutris.de/Fahrrad/Kurbelkuerzen/index.html

the 100% perpendicular part is what is stopping me from doing it myself. each mistake will add up to just paying this guy to make them:

http://www.bikesmithdesign.com/Short_Cranks/s600.html

$140 delivered for the cranks shortened to 120mm

question is I will probably have to buy a new BB

 

[izeman]

i think $140 is a good deal. if you haven't done it before and don't have the tools it could take a whole weekend to do it. and if it's not for the fun of doing it, i would let some pro make it

 

[chisixer6]

I have a 20" rear 9c motor that I got from grin cycles already radial laced 36H. I installed it in a 24" frame, dropout are no problem, it fits. Only problem is handling the wheel/motor assembly, it is heavy, but workable. I use Sinz 140mm length cranks, does not hit the ground on corners. Acceleration is awlsome, that's where the fun is at. tires are 20" Maxxis ringworms, great standover height. i loved small wheel bikes, got 4 small wheel ebikes.

 

[John Bozi]

For anyone searching or just to let those on this thread know that the 120mm cranks, 19" rim with 20" tyre rocks and is well worth it.
http://www.youtube.com/watch?v=0PsSWbOivrY&feature=share&list=PLzqojlpNeKR3t_VglNJXlBRmy_6rz9GuX