Originally Posted by
stephr1
The only thing I don't know is if my current freehub could handle an 8-sp cassette (certainly not a 9-spd).
If you have a 7-speed cassette on there with no extra spacers behind it, you have a 7-speed Freehub which can only be used with 7S cassettes unless you do a "8 of 9 on 7" thing where you use 8 cogs of a 9 speed cassette on your 7S body.
The current "standard" Shimano Freehub body works with 8, 9, or 10S cassettes. Realize if you go to any of these you'll need new shifters and chain at the very least, and of course the proper cassette and Freehub body or new rear wheel.
I would leave it at a new 7S cassette and chain and call it a day.