Originally Posted by
blamp28
Most likely, you have a freewheel rather than a cassette. If so, you would need the appropriate freewheel tool to remove the old one. any LBS should do this for a very low cost or perhaps free if you are buying something there. Spacing may be fine so laong as you end up with the 135mm that it is now from locknut to locknut.
Freewheel on an early 2000s era hardrock? You really think that it came with one?
I almost bought a mid 90's hardrock a few months ago and it had a freehub/cassette on it. It seems to me that almost all decent LBS based mountain bikes from the early '90s and up have freehubs and cassettes. My Fuji, Specialized, Giant all have freehubs on them and they are all from the early '90s. As far as I know, mainly cheaper box store MTBs had freewheels.