Worn cassette measuring

02camaro

Well-Known Member
Is there any way to measure or check a worn out cassette?

I have several bikes and swap wheels around so it's a little challenging to keep track of miles. To my eyes this doesn't seem worn but it was shifting like ass in certain gears so I changed it.

I'm surprised there isn't some kind of guage to measure wear for cassettes.

Shimano XT 12s. If I had to guess Ive gone through 3or4 chains on this so I know it's at the end of its lifespan but I still cant visually see the difference between a new and old one.

20230220_160547.jpg
 

onetracker

Well-Known Member
Is there any way to measure or check a worn out cassette?

I have several bikes and swap wheels around so it's a little challenging to keep track of miles. To my eyes this doesn't seem worn but it was shifting like ass in certain gears so I changed it.

I'm surprised there isn't some kind of guage to measure wear for cassettes.

Shimano XT 12s. If I had to guess Ive gone through 3or4 chains on this so I know it's at the end of its lifespan but I still cant visually see the difference between a new and old one.

View attachment 207862
There is no cassette wear indicator tool in existence to my knowledge. However, this cassette does not look worn out. Switching between chains is likely the issue. You can check chains for wear using a chain wear indicator tool.
 

kaitlyn

Well-Known Member
Is there any way to measure or check a worn out cassette?

I have several bikes and swap wheels around so it's a little challenging to keep track of miles. To my eyes this doesn't seem worn but it was shifting like ass in certain gears so I changed it.

I'm surprised there isn't some kind of guage to measure wear for cassettes.

Shimano XT 12s. If I had to guess Ive gone through 3or4 chains on this so I know it's at the end of its lifespan but I still cant visually see the difference between a new and old one.
There are sprocket wear tools, they're basically a length of unworn chain. Such as: https://uniortools.com/eng/product/1658-2P-sprocket-wear-indicator
 

Karate Monkey

Well-Known Member
The sprocket wear tools that KMC, Unior, Rohloff, et al, manufacture don't really work with modern cassettes--their teeth are too profiled/short to take consistent readings.

That said, you can wrap a literal length of chain ~halfway around each sprocket, and try to lift the center span. If you can get any significant movement, the sprocket is worn out. You check chainrings the same way.
 

kaitlyn

Well-Known Member
Hmmm. Now I have a 3d printing project. I think I'll make a model of an unworn cassette, print out the reverse image of it and use it to measure wear. Fun exercise.
 

Santapez

Well-Known Member
Team MTBNJ Halter's


What's the shop policy if you catch a mechanic using one of those as a cassette removal tool?
 

JonF

Well-Known Member
I have a cassette that has been jumping the chain, specifically in certain harder sprinting gears. When you put a load on the chain with just pushing the crank by hand, you can see it wanting to lift up and out of the teeth on that cog. It was suggested to me to try checking the derailleur hanger first since it can have some influence on this condition and while mine did need a very miniscule tweak, the issue still persisted after adjustment. Dialing in a little more chain wrap helped some but also still jumping.

For reference, you can see the wear here:

 

CRGH81

Member
Is there any way to measure or check a worn out cassette?

I have several bikes and swap wheels around so it's a little challenging to keep track of miles. To my eyes this doesn't seem worn but it was shifting like ass in certain gears so I changed it.

I'm surprised there isn't some kind of guage to measure wear for cassettes.

Shimano XT 12s. If I had to guess Ive gone through 3or4 chains on this so I know it's at the end of its lifespan but I still cant visually see the difference between a new and old one.
Hi, I'm not aware of any tool, but the best way to evaluate it is seeing if the teeth looks like a plateau (square top -like new) or if they look more like a shark's teeth or a big wave (pointy). If they are more like shark's teeth, it's because you have worn out the edges of the originally square top. Sadly, your cassette looks ready for retirement, as it has too many teeth completely worn off and others coming in close. I'm marking in your pic some examples with red (dead) and green (ok). Hope you can see the difference!
To maximize the lifetime of your cassette / crankset, always keep an eye on the chain (there are several tools to check it), as this is the piece that is meant to be easily replaced.

1677212270649.png
 

JPark

Well-Known Member
Hi, I'm not aware of any tool, but the best way to evaluate it is seeing if the teeth looks like a plateau (square top -like new) or if they look more like a shark's teeth or a big wave (pointy). If they are more like shark's teeth, it's because you have worn out the edges of the originally square top. Sadly, your cassette looks ready for retirement, as it has too many teeth completely worn off and others coming in close. I'm marking in your pic some examples with red (dead) and green (ok). Hope you can see the difference!
To maximize the lifetime of your cassette / crankset, always keep an eye on the chain (there are several tools to check it), as this is the piece that is meant to be easily replaced.

View attachment 208037
I think some of the teeth are supposed to be angled to allow for easier shifting.
 

CRGH81

Member
I think some of the teeth are supposed to be angled to allow for easier shifting.
I think you are right! I was reviewing and there are some that are angled for easier shifting. I´m no expert, but I usually go with when the teeth are like pointy mountains/shark teeth. Of course, issues with the chain jumping is an annoying indicator, so visually I have nothing more to add! Sorry if it added more confusion than anything!
 

Ironjunk

Well-Known Member
This is a good question. The rollers are nestled between the cogs and only put pressure at a single point shared.

When the chain pulls at the cassette how much rollers share the load on the cassette? Does just one roller pull? One and a small percentage of the one behind it?

As a cassette wears and i assume the curve of the cog becomes flatter does the small amount of lost surface area matter when the roller is pulling the cassette cog?

Perhaps the best indicator of a worn cassette is the amount of backlash of the chain pulling a stationary cassette.
 
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