Trying to remove my M770 cassette but it's a little different from anything i've seen before. Essentially the cassette tool wont go in more than .5mmm into the guide teeth because of what looks like an extra ring inserted in the the space.

Do i use the skewer to press the ring in to let the tool bite or do I attempt to pull this ring out?

Or is it knacked?

Cheers

Bumped to get me riding this weekend please!!!

picture?

What kind of hub?

Nowt special about those cassettes, wiggle the tool a bit more. There is a washer behind the lock ring, but that shouldn't be causing problems.

I've seen an old, old XT hub (can't remember exactly which) with a 770 cassette, where a locknut on the axle prevented the cassette tool locating properly. I wasn't doing the job, but it was shown to me as 'any-ideas' sort of thing.

The feller ended up smashing the axle through the lock ring to get the cassette off, and junked the wheel.

Well if the previous owner managed to get the lockring on, it ought to come off again.

I've found that by turning the QR nut round it will sit inside the removal tool enough to let you thread the skewer through the spindle and the tool so you can get it to grip real tight, then use an adjustable spanner to undo the tool.

Cheers for the reply chaps. The hub is a splined XT and he's a few pics. I've never taken it off but just lately it feels like i'm riding with the brakes on, I think the bearings need a look but before I can do that I have to get this off.

You can just make out the inner ring on the inside, it's about 0.5mm below the lockring face.

looks like a spacer / seal on the axle???

Strip the axle out then remove the cassettee?

What TJ said – that's never coming off otherwise.

Somebody has added a washer after the cassette was fitted.

Probably because the chain wouldn't drop into the smallest sprocket as the hub had been reassembled wrong.

Take off the nut and washer, take it all apart and start again.

I bet you find the washer came from the other side of the hub.

Either that or the d/s side cone / locknut has unwound itself moving outwards into the space needed for the lockring tool.