Does This Need Replacing?

[forrest101]

My local bike shop has quoted several hundred £’s to service my EMTB. Amongst the items they say are “worn out” and need replacing are the chainring, cassette, chain, and jockey wheels. The bike has covered 1200 miles since new but the cassette, chain and jockey wheels were replaced just 200 miles ago. The cassette doesn’t look all that worn to me and is not causing any issues. Is it possible to verify from the attached images if the cassette is “worn out” and requires replacement? I have included an image of a brand new cassette for comparison.

 

[Mik3F]

Doesnt look worn out to me,

Does it still shift nicely?

This could just be the LBS trying to make some money out of you

 

[RustyIron]

You can't really be certain about a cassette just by looking at it, but yours looks fine. Why did they replace all the parts only 200 miles ago? What symptom are they trying to resolve now?

 

[steve_sordy]

I have looked very carefully at the image of the old cassette, even blown it up on the screen. There are some signs of wear, but not many. Some of the tips of the teeth have small burrs caused by excessive pressure from the chain rollers forcing the metal of the teeth over to the sides of the cassette. But I can't see it on every gear. If you want to take the trouble the burrs can be filed off the sides of the cassette, but only worth doing if they are causing shifting problems. If you were able to ride in one bigger gear all, the time, ie a faster cadence that would reduce burring because you would be putting reduced tension into the chain.

I see no signs of tooth face wear, no shark finning, no elongation of the tooth roots. That cassette looks fine to me.

It is not often appreciated that one worn component on the transmission can knacker all the others quite quickly, like mechanical AIDS. Measure your chain on a regular basis and instead of getting the maximum out of it, err on the side of caution and you will be rewarded by longer life from your chain ring and your cassette. The only time that I let a chain just run and run is when I'm planning to replace the cassette. A new chain will not run on a worn cassette, but your old one will run quite happily. Just don't forget the chainring!

PS : Find another bike shop.

 

[forrest101]

I replaced the cassette and chain myself 200 miles ago because they were worn and causing shifting issues. I didn't change the chainring at the time because I don't have the tools. I took the bike in recently to have just the chainring changed as it does look very worn but they tell me the cassette and chain are also "worn out" and need replacing.
There are no shifting issues everything works as it should. I suspect they think I am some sort of mug.

 

[Polar]

If they say it's all worn out but you feel everything is working fine then just keep on riding until it all collapse and then buy new.

 

[RustyIron]

There are no shifting issues everything works as it should. I suspect they think I am some sort of mug.

I suspect you're correct. Chain checkers are cheap. You need one anyway, so get it and you'll see for sure whether they're trying to play you. You can also get the wrench for the chainring, and you can be done with those jokers forever. Honestly, 1200 miles isn't much for a chainring. If your bike is running fine, you might want to leave it.