Need a new rear cassette (I think)

DiscoStu73

I snapped a rear mech a wee while ago and have just gotten round to fitting a new SRAM X-7 after a winter of no biking.
I changed the old chain while I was at it, to a SRAM PC-991.
But now I'm getting constant slippage when I am going uphill or am pedalling in slightly too high a gear (which I do to build up leg strength).
I've heard that new chains don't like old cassettes, so do I need to change the cassette too? The kit on my bike is a few years old, so there must be wear on the cassette by now. It's a Shimano 760 cassette, and the old chain is another SRAM PC-991. If I put the old one back on everything runs fine!
It's new cassette time, isn't it?

nicklouse

first work out where and what is slipping.

it could be the chain on the chain rings, it could be the chain on the cassette.

or it could be the free body.

DiscoStu73

It's definitely on the rear cassette. I can see it when it happens! I usually only use rings 3-8, and the new chain doesn't settle on any of them if there's pressure on the drivetrain. Put the old chain back on and everything's fine again.
I bought the bike 2nd hand last year and the kit on it was a couple of years old then, so the cassette is at least 3 years old, if not more. I think the old chain is probably as old.

nicklouse

then yes you need a new cassette.

DiscoStu73

Bother.

Well in that case, if I'm running SRAM chain and mech, should I change to a SRAM cassette, like a PG980?
Like I said before, my current cassette is Shimano. Are there any positives/negatives about putting an XT 770 cassette with my new SRAM gear?

Here's another thought I've just had: are cassette removal tools universal? I've just seen one on the Evans site that says it's 'for Shimano cassette'...

John Stevenson

If putting the old cassette back on fixes it, then it's very very likely that, yes, you need a new cassette.

-liam-

Sram and shimano use the same lock ring tool. You will also need a chain whip.

GHill

DiscoStu73 wrote:

Well in that case, if I'm running SRAM chain and mech, should I change to a SRAM cassette, like a PG980?
Like I said before, my current cassette is Shimano. Are there any positives/negatives about putting an XT 770 cassette with my new SRAM gear?

I prefer the XT cassette, even if everything else is SRAM.

DiscoStu73

Cheers guys.
The Shimano/SRAM mixture was concerning me, even though it's a mix that I'm currently using.
I think it's the fact that I bought the bike 2nd hand, so have inherited someone else's spec. Having just replaced the mech and chain, it crossed my mind that I should maybe take the chance to change to all SRAM in case that was the 'correct' thing to do.

I've been looking this up today and it sounds like the XT cassette is the preferred option. I don't really care which manufacturer I use, just so long as everything works!

-liam-

Sram pg970 is half the price of the xt on chain reaction...

http://www.chainreactioncycles.com/Mode ... delID=5213

You could probably get it a quid or so cheaper on fleabay

x-isle

If you are using Hope Pro2 Hubs, then be careful on your cassette selection........

richg1979

shimano slx are pretty light (bout same as xt) and can be had for £30, found these last longer than sram cassettes too.

joshtp

its a pretty widely accepted fact that Sram chains are better, and Shimano cassettes are superior.