Just put on a new chain and now i'm asking myself if this fancy XTR 12speed cassette needs to be replaced. What do you think? Is this normal shape of the teeth?
by mbergi
Just put on a new chain and now i'm asking myself if this fancy XTR 12speed cassette needs to be replaced. What do you think? Is this normal shape of the teeth?
by mbergi
9 Comments
Does the new chain skip in those gears when pedaling under torque? If so, then new cassette, if the chain doesn’t skip, it’s all good. New chains are your cassette checkers.
Junk it. I just got a nice one for $20.
Looks OK. But the only real way to tell if a cassette is worn, is to put a new chain on and see if it skips on any cogs under load. If it doesn’t then it’s good to go.
It’s still in phenomenal condition. Unless you plan on changing your cassette size, its not worth replacing.
> Is this normal shape of the teeth?
If, in particular, you’re asking about the really ugly teeth I’ve circled, those are intentionally low and oddly-shapen as they are the “entry point” teeth when you downshift which is why they’re on the tail end of the [lift ramps](https://i.imgur.com/tEGNDTO.jpeg)
Except for some signs of shifting under heavy load, the cassette looks fine. Are there any symptoms of a worn cassette? Slippage? Snagging of the chain? Other?
Looks extremely worn. As long as it works with the new chain, you should be good to go. But if it doesn’t work with a new chain, then you’ll need a new cassette. Often times, there’s several cassette options so you don’t have to replace the cassette with the exact same one. I use SRAM and Shimano cassettes interchangeably on my road bikes since I have a variety of bikes and wheelsets. When I ride my DA equipped bike no one says hey that looks like a 105 cassette.
On the repair stand nothing skipping. But maybe I need to go for a ride to test it under load?
Those larger cogs are aluminium, abrasion of the anodising on the side is totally normal. It’s much weaker than the steel of the chain.
Replace-me levels of wear would look like the squared-off teeth becoming narrow, and would manifest as the chain jumping over the teeth (rather than jumping from cog to cog)
Cassette wear is linear. The longer you let it wear, the more that uneven wear will affect the performance of a new chain and also increase the wear on your chains rings.
If your cassette is cheap, and your chain rings are from white industries or are dura ace, then yes, absolutely it’s way past time.
If your chain rings are cheap, and your style of riding doesn’t cause a new chain to skip with this worn of a cassette, then keep doing what your doing.
I change my cassette often on my bike that has premium chain rings. But mainly because I want to prevent wear to those expensive items which I do not want to replace.
As for gauging cassette wear, you can see the deformed teeth with additional material that’s been squished (mushroomed) at the left side of the teeth. So this is certainly a worn cassette.