Stuck cassette lockring
 

Any ideas on getting a very rusty, very stuck lockring a-loose from a Shimano 7-speed cassette? It's stuck on so bad, when I really leaned on the chain whip and wrench attached to the ring tool, the plates on the chain link where it attaches to the chain whip spread apart, and the chain section flew off it.

No biggie. It's rusty because I FOUND this wheel. Yes, in the trash. The freehub clicks nicely, and the hub bearings are actually quite smooth. So I thought I'd throw a knobby or studdy on it to use as a winter wheel. It'd be nice to get those cogs off, but I'm not gonna cry if I can't.

liquid wrench works wonders,and some choice words

You could saw it out with a hacksaw.

Maybe try to soak it in some kind of degreaser, or even kerosene or some king of rust remover.. Then attack it!

Jay

Dremel
 

I had one that I couldn't get loose. I took my Dremel with a cutting wheel and cut the lockring off.

Try heating with a blowtorch being careful to only let the flame hit the crucial areas of the sprockets and the retainer ring. Let area cool for a few seconds and try to wrench it again this along w/ liquid wrench is really your best shot.

Use an impact wrench (the kind that use compressed air) and a large socket that fits the cassette tool. Use your new chain whip to hold the cogs and the impact wrench to loosen the lockring.

I'd also soak in liquid wrench first. If you don't shear off the teeth of the cassette tool, the ring will give up.

You might start with the low torque setting and work your way up!