Bicycle Mechanics - help with rear cassette

hello all
i found a bike on the street and i'm trying to put it together for a friend. it basically just lacked a few things that i pieced together (a chain, the rear axle needed tightening, a new seat/post, etc) and now with a front wheel it will be a great bike! EXCEPT - i can't for the life of me figure out why the rear cassette doesn't spin - almost as if its fixed, but i dont think it is -it is a 9 speed with working derailler, etc. i unfortunately don't have a chain whip to take off the cassette, but aside from bringining it somewhere (or to someone) who does have that, could someone shed some light on *why* this might be? the locknut is not too tight on the rear axle (i checked), its super greased/lubed up (i just did it). i would rate my mechanic skills at a 7/8 out of ten (repack front hub, not rear though) so I'm genuinely confused about how to proceed, or whether its just shot and i should ditch that rear wheel...
thanks very much
bikey

You "found" a 9 speed bike on the street?

oh for gods sake. are you kidding?

You don't consider it an uncommon find?

Anyway, if the cassette won't spin, the problem is in the freehub body. The bike must have sat outside for a long time for enough water to get inside the freehub and corrode things enough to not work any more. You might be able to get away with replacing only the freehub, assuming you can find a replacement that's compatible with the hub. Replacing it will require remove the axle then using a 10 or 12mm hex key to remove the hollow freehub bolt. The freehub will come right off the hub. Of course, you need to remove the cassette first which will require a cassette lockring tool and chain whip. If the freehub is frozen up sufficiently though, you may not even need the chain whip.

thanks for the straight answer, joejack. i thought you were making an oblique reference to theft which, given my posting history on this board, i think is pretty out there. often in new york one bikes around and finds old thrown out stuff, and sometimes it is a bike, yes.

Well, I sort of was :) I've never seen anything better than a 1980's Ross road bike in the trash but I don't live in a very big city either. I will admit that I'm jealous of your find too.

look on the bright side: i need a rear and front wheel now, and they're impossible to find cheaply here in new york. out in smaller cities and in the midwest where i grew up, i could probably find a whole bike for $30 in a garage sale that here would run like $230. sigh.

I've heard of some steals through Craigslist for bikes in some cities. Around here, I buy them cheap on Ebay (not as often as I'd like though) and resell them on Philly's Craigslist where people are willing to pay top dollar for anything in half decent shape. It's almost too easy.

As far as no chain whip a rag and someone with a strong grip can work. Or an old piece of chain and a vise grip pliers.