Doe my cassette look worn?

[nmfeb70]

Hi all, I fitted a new chain to my Trek MTB yesterday and it started skipping in the highest gear/smallest sprocket. Thinking it was too long (even though I sized it up against the old chain) I took one, then two, then finally three links out and the problem still persisted, the chain was then too short (Doh!). I have put the old chain back on the bike and everything is fine. I know what you're now thinking - a worn cassette is the problem - but the cassette looks fine to me?
I've attached a photo, albeit the sprocket in question is a little difficult to see.

I will add that I am meticulous when it comes to cleaning the chain and I replace it as soon as it borders on 75% worn. The cassette has been through three chains. Thanks.

 

[fossyant]

If the cassette has done three chains you've had your moneys worth. My commuter gets chainring, chain and cassette changed every 12 months

 

[Paulus]

As @fossyant says. The new chain is skipping because the cassette is worn.
Time for a new cassette.

 

[cyberknight]

If the cassette has done three chains you've had your moneys worth. My commuter gets chainring, chain and cassette changed every 12 months

you do well then , i get through a couple of chains a year on my commuter ,the joys of country lane commuting currently covered in mud from the fields as the farmers are harvesting .

 

[mickle]

You can't usually tell if a cassette is worn just by looking at it.

 

[alicat]

If a new chain skips and the old one didn't, the cassette is worn. End of story.

 

[Red17]

If it's only skipping in the highest gear then might be worth tweaking the limit screws on the derailleur to see if that helps

 

[C R]

If it's only skipping in the highest gear then might be worth tweaking the limit screws on the derailleur to see if that helps

The chain will skip in the most often used cogs of a worn cassette. For most people those would be in the middle of the cassette, but maybe the OP uses the smallest cog often, and having a small number of teeth that will wear more quickly. Normally you don't see limit screws needing adjustment if the derailleur has been properly set up, and changing a chain should not affect the derailleur set up.

 

[Dogtrousers]

I've read on here, from people who claim to know what they are on about, that, unlike chainrings, it's not possible to detect wear on a cassette by visual inspection. That may or may not be true.

I use the test that you're using: If it skips on a new chain it's worn. If it doesn't it isn't.

 

[OldShep]

After fitting a new chain I pedal gently and if slipping I’ll put up with slipping for about 20 miles. If it’s still slipping after that I’ll buy a new cassette.
Yorkshire born and resident in Scotland what do you expect 😀.

 

[nmfeb70]

Thank you, guys. I was going to order a new chain only and see if there's any difference, but I'd probably be in the same situation. As some of you have said, I've had my money's worth so a new cassette it is. Many thanks.

 

[Punkawallah]

If it's only skipping in the highest gear then might be worth tweaking the limit screws on the derailleur to see if that helps

Or finding a cassette to donate the worn gear.

 

[wafter]

Can't tell from the pic, but as others have said 3x chains (all to 0.75% wear, too) sounds like the cassette's given good service and conforms to the (legit or otherwise) adage of 3 chains to one cassette..

Or finding a cassette to donate the worn gear.

Indeed; if you want to be really tight you can usually buy the smaller ones new; would be interesting to fit one and see how long the rest of it lasts.

 

[Gunk]

Get an electrical screwdriver and drag it gently over the edge of the teeth, if there is a small lip then it’s worn

 

[I like Skol]

You can't usually tell if a cassette is worn just by looking at it.

Maybe it's just me, but apart from the largest sprocket and the smallest one that is mostly obscured, that cassette looks to be clearly well worn with an obvious deformation of the teeth at the pressure point! Defo need to bin the whole cassette, shame you ruined a good chain.