Originally Posted by
holmes123
the frame spacing on my bike is 135mm which doesn't seem to make sense for a 7speed. If i buy a 9 speed hub with a 9 speed cassette and 9 sp shifters will i need to do any other mods?
Is it neccessary to change the hub?
135mm rear spacing is the standard that was rolled out in 1989 along with 7 speed hyperglide. The whole "7 speed MTB is always 130mm" is an ugly internet myth that just won't die. There were a few frame builders that stuck their heads in the sand and hoped standards would never change, and Shimano accomodated them by offering the new seven speed groups with 130mm rear hubs for a limited time, but they all had to face the music eventually.
You could change the freehub body on your seven speed hub to upgrade to nine, or buy a new rear wheel. It would probably not be cost effective to lace a new hub up to your old rim.
You could also try Sheldon's "eight of nine cogs on a seven speed freehub body" and keep your rear wheel intact. Don't forget you'll need a nine speed chain too.