plgcp

Please see closeup photo of the just-cleaned large block of my CS-4600 Tiagra 10-sp cassette. Recently I replaced my chain for the second time (ie this is now the 3rd chain). Total distance on this cassette is roughly 6,000-7,000 KM. My shop told me the cassette is OK and it does seem early to need a new cassette but I'd like a second opinion from you guys. My shifting is noticeably worse with the new chain - not so much skipping as the shift commands don't always take while they were perfect before - plus I see ridges on the edges of the teeth of my most-used cogs (3rd, 4th and 5th largest ones in the photo).

Are these ridges a sign that those cogs especially are worn out or just that they're partly worn? Is the best test now to hold the brakes firmly engaged and push the crank to see if the chain rides up?

ThermionicScott 

The ridges just mean that the cassette is wearing, some of mine look like that. I wouldn't replace it until a new chain flat-out skips. 6000-7000 km isn't a lot for a cassette if you've been replacing chains in time.

andrewclaus

A worn cassette will not cause the shifting problem, that's something else like maybe a different chain make/model, an adjustment got slightly tweaked, or something got bent.

Rohloff makes a cog checker tool, but I hear it's of limited use and your shop may not have one or think it's worth it. Otherwise, there's no good bench test.

HillRider

Even with timely chain replacement the most used cogs will show some wear. However, if the chain isn't skipping under load the cassette is still ok. I agree the shifting sluggishness is likely to be an adjustment issue.

Bike tinker man

To my eyes the cassette looks fine, these modern ones the teeth are all chamfered, & different profile to allow smoother gear change.
If this has only shown up worse since you installed the new chain ? put the bike on a stand turn the pedals & go through the gears & see if you can pick out why its not running properly, maybe in the RD ?

plgcp

Thanks all for the quick replies. This is a different chain (shop apparently only had Ultegra while I had 105 before). The shop also likely tweaked the indexing while I had it in and they might have worsened things. I'll get it up on the stand and check derailleur hanger and jockey alignment and the indexing.

grizzly59

The only test I've found for cassettes that works is to swap on a new one. First, a new chain with the old cassette. If that fixes it, great. Still problems? Try a new cassette. Problem went away? Old cassette was worn.

AnkleWork

Maybe compare with a new cassette?

CliffordK

There definitely is a fair amount of wear on that cassette, and some elongation of the valleys between the teeth.

My rule is that if the chain skips, then replace the cassette with either the current (new) chain, or perhaps wait until it is time to replace the chain the next time.

Sometimes mild skipping gets better as a replacement chain wears.

If it isn't skipping, or only rarely skips, then keep riding.

I agree, your shifting woes are probably something else. Either a derailleur out of adjustment, or time to also replace the cables and housing. Or, sometimes you can lube the cables and housing.

DaveSSS 

If you want to get maximum life from a cassette, alternate the use of 3-4 chains. The casette will last for the life of all the chains. With campy, that can easily be 12,000 miles.

Even if you get some chain skip with a new chain, you'll find that it will work fine with a chain that has only a few hundred miles of break-in wear. Get a new cassette, break-in the chain and then put the old cassette back on.