Originally Posted by moxfyre
Uhm... do you have a rear derailleur that can handle a 42 tooth rear cog? It's not even a question of having to use a very small chainring with it... I doubt the pulleys will clear the cog. I had an old MTB wheel with a 34T cog and my long cage derailer barely cleared it.
Also, no way you're gonna be able to shift on and off that thing. Hard to space it right, and wrong tooth profile.
Sun made rders to accomodate their 38T freewheels/cassettes. You might be able to push the envelope 4T. Could also make your own rder mount/carrier that sits fore and/or lower than norm-it'd reduce shift quality but would still clunk through it.