26" rim onto 21" motorbike wheel

[Bluefang]

Hey guys, I have a E-bike that i have been using a Pitbike front end for with a 21" motorbike wheel. I recently got tired of all the extra weight so i decided to removed the steel motorbike rim and motorbike tire and they together weighed about 7kg+ to replaced them with a normal double wall rim and a bike tyre.

Never laced a wheel before so i started with something abit different . First go the spokes were not quite long enough so i needed to modify the spoke holes on the hub, looking at the pics they are 15mm thick so i drilled them out to be only ~5mm thick which made them close enough that the wheel could be laced to gether. Would be alot better if the 26" bike rim was a double wall Aero design rim rather then the normal one then you might get away without drilling the spoke holes. I needed to drill the spoke holes on the rim larger, ~6mm for the nipples and 12mm for the nipple heads.

So for a cheap and easy suspension setup that will handle more abuse then you can dish out some light weight motorbike forks from say a CB90 or a small dirt bike can easily be modified to handle normal bike tires too.

 

[spinningmagnets]

I think John Rob Holmes can make custom length spokes, and I'm sure if anyone wanted a beefy hub like this, he could quote you a price for building one up...
http://endless-sphere.com/forums/viewtopic.php?f=31&t=16218&start=0

Another popular mod for high power bikes is a fat moped tire on a 20" heavy-duty rim, which ends up having the tire diameter of about 24".

 

[amberwolf]

@SM: JRH has actually already built at least one wheel like that, IIRC, with a beefy MC-ish hub. Cant' remember if it also had a MC / Moped rim, or a bike rim, though.

Myself, I'd do things the other way round: Use a heavy-duty rim and spokes, and not care much about the hub part (probably using a bike hub). But my cargo bikes have to take a lot of pothole/etc abuse at times, when heavily loaded.