# How to check cassette wear?



## JTS628 (Apr 22, 2003)

"New" used bike added to my stable with 8-spd Chorus. Using ye olde ruler method, chain is almost 1/8" stretched and will be replaced with a SRAM. The cassette looks OK, but since I know nothing about the previous owner's maintenance, is there some quantifiable way to check cassette wear? I've seen a Rohloff tool on the web for Shimano IG cassettes, but never actually for sale anywhere, nor any explanation of why it would only work on Shimano cassettes.

This is a wide range 8 spd cassette and fairly hard to find new so I'd prefer not to prematurely throw the cassette away (which I'd do in a second if it were a Shimano cassette). I'd even settle for a good rule of thumb for that gray area between fresh-from-the-dryer clean and shark fin (something more than the "ride it and see if it skips" rule). Thanks much.


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## C-40 (Feb 4, 2004)

*install a new chain..*

Install a new chain and if the chain doesn't skip when applying substantial power (like pedaling when standing) in any of the cogs, then it's not too worn to use. 

The 1/8" stretch rule is outdated. Most recommend changing far sooner, at not more than 1/16 inch stretch per foot. You may well have worn out a few of your cogs by using this chain too long.


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## Spunout (Aug 12, 2002)

Look for deformations on the load bearing side of the teeth, usually on a most-used cog. Some might use a dremel tool to grind these off, giving you a bit more life and quieter. I dunno. Definitely change the chain. If it performs badly, you`ll needa new cassette.


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## bimini (Jul 2, 2003)

*I agree, if the cassette doesn't skip*

with a new chain, I keep using it. It is the approach I use. There is a problem with this approach, if the cassette is just marginally worn it will skip on you at the worst possible time. At the peak of an all out sprint or on the toughest incline on the toughest hill. I've taken some nasty wacks on the side of my thighs where the chain let loose & I caught myself with my thigh on the top tube before flying over the bars. I'm cheap so the risk of a bruise is worth the price of a cassette. Some avocate replacing the cassette with the chain, this makes a lot of sense for the pros or those that put a lot of power into the pedals (and aren't tightwads). 

I also wacked my nads on the top tube when my chain skipped, causing a foot to come unclipped and my crotch caught the top tube as I was slamming down with all the force I could muster. I saw stars.



C-40 said:


> Install a new chain and if the chain doesn't skip when applying substantial power (like pedaling when standing) in any of the cogs, then it's not too worn to use.
> 
> The 1/8" stretch rule is outdated. Most recommend changing far sooner, at not more than 1/16 inch stretch per foot. You may well have worn out a few of your cogs by using this chain too long.


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## CoachRob (Sep 14, 2004)

*Here's the tool*



JTS628 said:


> I've seen a Rohloff tool on the web for Shimano IG cassettes, but never actually for sale anywhere, nor any explanation of why it would only work on Shimano cassettes.


http://www.rohloffusa.com/frame.htm

Click on "Products" in the upper left, then the HG/IG link. They too discuss its use on Shimano cassettes. However, I just checked in Barnett's manual, and he writes "excellent tool for checking wear on *all* cassettes". Apparently he is trying to dispell a myth that it is just for Shimano cassettes, even though the mfgr states it is.

What I find curious is HG stands for hyperglide. The cassettes that preceeded the HG were the uniglide. SO, where does the IG come from? Shouldn't it be HG/UG, not HG/IG? Does Campy make IG cassettes? I don't know about Campy components, but it doesn't sound like a designation they would use (not fancy enough).

You can call Rohloff in California at 1-(510) 232-4833. If you do call, would you mind posting what they tell you?

That's the best I can find in Barnett for you on this subject.

It's for sale at http://www.mtbstore.com/products/Ca...hloff-HG-IG-cassette-wear-indicator-tool.html

Each cog on the Campy Record 8-speed (can't find Chorus or Shimano info) is 1.9 mm thick. Campy uses 3.1 mm black resin spacers and spaces their cogs 5 mm on center. That is, the distance from the center of one cog to the center of the adjoining cog, measured from the center of the first cog to the center of the second cog, is 5 mm.

But I don't think cog thickness is a factor as the HG/IG is designed to check for wear on all Shimano cassettes, not just 9- or 10-speed, and thus must accommodate different cog thicknesses. It looks sort of like a chain whip. Strange tool it seems.


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## MR_GRUMPY (Aug 21, 2002)

IG was a type of chain and front chainrings to go along with them. It was made for MTN bike triples to help speed front shifting.


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## JTS628 (Apr 22, 2003)

Thanks for the replies. I was hoping there was a method better than trial and error but it sounds like there is not. Here's hoping I don't repeat Bimini's 'nad smack . . .


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## agentorange (Nov 27, 2004)

CoachRob said:


> http://www.rohloffusa.com/frame.htm
> 
> Click on "Products" in the upper left, then the HG/IG link. They too discuss its use on Shimano cassettes. However, I just checked in Barnett's manual, and he writes "excellent tool for checking wear on *all* cassettes". Apparently he is trying to dispell a myth that it is just for Shimano cassettes, even though the mfgr states it is.
> 
> ...




I use this roholoff tool regularly and yes it only works correctly on shimano cassettes. The last roller of the chain is oversized and should "stick" when pressure on the handle is applied, and when this is used on a sram cassette, it is just all loosey-goosey, even when brand-new. (tested it just minutes ago just to be sure!). can't remember for campy, not that they(campy cassettes) really ever wear out if you replace you chain regularly anyways! 
one way i've used in the past for shim,sram,campy cassettes is to eye the edge of the cog where the chain contacts the cog and where the force is applied. Look for the "flashing" around the edges. if the flashing is apparent on the back-side, but not on the front side, where the force of the chain is applied, then that cog is worn. not too scientific, but works well. dont use this method if your cogs are cut with a burr, only use if stamped and machined, or whatever. sorry for making up so many words  not sure I can ever understand what I just wrote!


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## gambo2166 (Oct 20, 2004)

The tool works well. If the test roller moves freely in the tooth pocket your HG-IG sprocket is still working well This indicates that even a new chain will run well on this used sprocket.

If the test roller hooks on the tip of the tooth or if you need to use some force to move it into the tooth pocket, the sprocket should be replaced.


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