RubeRad

Not really a question here, more of an invitation to feedback, mockery, whatever.

So 7 years ago I bought a 9-speed cassette, (lightly?) used off eBay. After near-daily commuting 11mi round-trip, and a little bit of other riding, I've put about 20,000mi on it, rotating 2 chains every 6mo. The past few years, I've been slipping the chain on a hard mash at a light or up a hill, maybe once or twice a month. No big deal, I'll deal with it when it's more serious.

Well now it's more serious. This morning I finally put on the new chain I bought a couple months ago (I ordered a KMC, they sent me a shimano, but still 9-speed so whatever). This thing is slipping like every 2-3 seconds! After twice slipping off and getting wedged between the cassette and dropout, I limped back home and drove into work instead.

I guess it's time for a new cassette.

I had always heard that chains and cassettes wear together, but I never imagined it could be this extreme! Looking at the cogs, they don't look shark-toothed at all to me.

Rolla

After seven years, I should hope so!

Cog wear isn't always blatantly visible. Chain wear and cog wear gauges are relatively inexpensive and handy tools to have.

RubeRad

Actually I've never heard of a cog wear gauge before. Could that same test be done with just a regular chain whip?

mack_turtle

I've used a cassette wear gauge tool and I found it to be useless. to test cassette wear:
1. install new chain
2. ride bike
if the cassette skips under the new chain and you didn't do anything else wrong, it's time for a new cassette.

RubeRad

Hey cool, I just did that test this morning!

cxwrench

You could but the chain whip is a bunch longer than the cassette wear thingy. Don't have it with me right now but I think my cassette wear tool has 4 link sets so it's a little easier to judge wear. If I can't push the last link down in I know I've got some serious wear. And cassette teeth don't get as obviously worn as chainring teeth. Not as shark-finny, more like the teeth get smaller and the gap gets bigger, flatter on the bottom. Chainring teeth will get the shark fin then get really short and pointy.

RubeRad

That's weird that there would be a difference. Seems like the same kinds of forces would be in effect, just in opposite directions

deacon mark

Cassettes are hard to judge when they are worn. The test is exactly what you did. You put a new chain on and the chain slips this is the indicator that the cassette is worn out. Cassette wear varies but usually if you put a new chain on when the old one reaches the mark to change you can get 3 chains to one cassette. I just did a drive change on my Shimano 6800, I had 17000 miles on the cassette and had gone through 3 chains, I simply decide to put a new chain and cassette on the bike. Then a few days ago I dug the old cassette out to put on another wheel I was converting to 11 speed. Well to tell the truth the bike shifted perfect so the cassette is really not worn out. But 17000 miles is a long way and generally I am pretty easy on drivetrains. I normally get 6000 miles on a chain and 6000 on Conti GP II 4000's so I cannot complain .You got 7 years you are way ahead of the game for sure.

Rolla

Maybe, but it's a lot easier with the tool. Catching the wear early and incrementally lets you extend the cassette's life by replacing the chain before it gets too bad.

Here's how it works:

RubeRad

New cassette arrived, I slapped it on (and took the opportunity to squeeze some grease into the rear wheel 105 bearings). Still it's skipping a little.

I think the problem is, this 'new' chain has stiff links. 3, to be exact, one of which is the quicklink. Can you find 'em?

RubeRad

What I thought I ordered was a KMC X9 chain, turns out on closer inpsection it was an 'unbranded' X9.93 'bulk' chain. Came in Shimano-lookin packaging though.

trailangel

Where did you buy the chain?

RubeRad

fleabay. And I ordered it Jul 30 and let it sit around before I got around to putting it on. I sent that pic to the seller, but I'm not optimistic.

trailangel

Somehow that doesn't look like a 9.93 KMC chain to me, which would have nickel x-bridge outer plate.
Get a new chain before continuing to troubleshoot.

RubeRad

fleabay seller offered partial refund of $2. I'll take it, and put it towards a ginuwine chain

RubeRad

Well it's definitely not KMC, it came in shimano packaging. The pictures, if you study the closeups, show 'shimano' on every link. I haven't checked the actual chain for that branding yet.

RubeRad

New KMC chain solved the problems, plays nicely with new cassette. (lightly used cassette actually, fleabay seller advertised as selling because he bought the wrong size, as you can see from pic it certainly looks immaculate)