Im trying to put my cassette back onto my rim and for some reason the spacer that goes behind it doesnt seem to be thick enough anymore. It is a 10 speed cassette and a shimano cassette body.What could be causing this? Thanks

Did you get all of the parts back on? Are the cogs equally spaced?

Check to see that the lockring is mounted properly, torque to specs, probably 40nm.

Al

I put all the cogs and spacers back with equal spacing and torqued to specs

Check to make sure that the smallest cog is positioned correctly on the freehub body, maybe it's not sliding on far enough.

Al

If it fit before, then it's "operator error". You either forgot a spacer, or you haven't pushed all the cogs down far enough. As Al points out, the easiest cog to mis-install is the smallest one.

Bob