# Help diagnosing noise after installing new chain.



## apctjb (Nov 20, 2002)

Just replaced my chain with a KMC 10XSL. My chain rings are Campy Record (Compact) and Record Cassette (13-29). Super smooth and quite on the flats but start to climb (+3% grade) and it turns supper noisy. You can hear each link messing as you push down, sounds like crap. Chain is well lubed.

Far worse noise when using the smaller chain ring in front. (large in rear); if I shift to the large chain ring in front the noise stops.

I tried switching out the cassette with another I had but same problem. I have under 2000 miles on the cassette and the compact crank.

So whats the problem? New cassette needed or new small chain ring or try another brand chain?

Help...


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## bikerjohn64 (Feb 9, 2012)

Was your previous chain a campy or KMC?
Are you using the missing link on the new chain?
2000 miles is not enough to cause that much wear on the cassette or chainrings to warrant a replacement.


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## metoou2 (Mar 18, 2009)

New chains can take as much as a month of frequent riding to 'mesh'. Just ride it.


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## looigi (Nov 24, 2010)

Correct chain length? B screw adjustment? (or Campy equiv?)


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## apctjb (Nov 20, 2002)

looigi said:


> Correct chain length? B screw adjustment? (or Campy equiv?)


 What is B screw adjustment.


The old chain was also a KMC and the chain length of new chain is approx the same as old.

I am using the quicklink connector that comes with the KMC; that is the same as the old one.

Any ideas as to why the noise on the smaller chainring but not on the larger?


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## hawkhero (Mar 28, 2006)

Chain could be too long. Shift into the small chainring and smallest cog on your cassette and see how the chain is. Does the derailleur cage take up the chain?


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## 32and3cross (Feb 28, 2005)

Check you chain rings they may be worn out. I had this happen on my cross bike - new chain new cassette horrible noise when climbing - turns out the rings were worn.


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## bikerjohn64 (Feb 9, 2012)

"The old chain was also a KMC and the chain length of new chain is approx the same as old."

The chains should be exactly the same length in order to rule out chain issue. If the chain length is 1" shorter or longer; you will have to make adjustments to your RD to accommodate for that using the tension adjusting screw.

Park Tool's website has good videos in regards to that.


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## apctjb (Nov 20, 2002)

bikerjohn64 said:


> "The old chain was also a KMC and the chain length of new chain is approx the same as old."
> 
> The chains should be exactly the same length in order to rule out chain issue. If the chain length is 1" shorter or longer; you will have to make adjustments to your RD to accommodate for that using the tension adjusting screw.
> 
> Park Tool's website has good videos in regards to that.



Yes the old and new chain have the same number of links but the old chain is slightly longer due to stretch than the new chain.

Thanks for all the suggestions. With less than 2000 miles on the chain rings I would hope they are not worn out but because the noise goes away when in the larger chain ring I suspect that a worn smaller chainring may be the problem


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## bikerjohn64 (Feb 9, 2012)

apctjb said:


> Yes the old and new chain have the same number of links but the old chain is slightly longer due to stretch than the new chain.


Can you see the difference or was that from measuring? 

If from measuring; how long was it at around the 12" mark from pin centre to pin centre?



> Thanks for all the suggestions. With less than 2000 miles on the chain rings I would hope they are not worn out but because the noise goes away when in the larger chain ring I suspect that a worn smaller chainring may be the problem


This may be the issue then.


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## UrbanPrimitive (Jun 14, 2009)

Is the noise consistent across your gear range, or worse when on the small ring and smallish cogs? It may seem silly, but this has to be asked to rule it out - do you trim your shift? Is the noise clearly coming from the front (chainring or front derailleur) or the back (rear derailleur or cassette)? There are a lot of possible culprits and we don't have much information to go on. The problem could be the chain, chainring wear, derailleur adjustment, chainstay flex, loose chainring bolts, or half a dozen other possibilities.

You mention the problem only comes up when you climb. Are you downshifting and spinning your way up, or are you mashing your way through? I know you said it's worst in the small ring, but it's still possible to mash depending on your cadence and cog choice.

You've had the cranks and cassette for around 2,000 miles. Is it fair to assume that's the last time you adjusted your derailleurs? Were new cables put on when the cranks were? Cable stretch would likely have shown up earlier, but may have gone unnoticed.

Is the sound a loud and clear clicking or muted? I've discovered that a significantly lubricated but dirty chain can make noise while _dis_engaging from the cogs.

There's a lot to look at, and rule out, with a problem like this. I hope you can figure it out without needing to throw much time or money at it.


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## apctjb (Nov 20, 2002)

UrbanPrimitive said:


> Is the noise consistent across your gear range, or worse when on the small ring and smallish cogs? It may seem silly, but this has to be asked to rule it out - do you trim your shift? Is the noise clearly coming from the front (chainring or front derailleur) or the back (rear derailleur or cassette)? There are a lot of possible culprits and we don't have much information to go on. The problem could be the chain, chainring wear, derailleur adjustment, chainstay flex, loose chainring bolts, or half a dozen other possibilities.
> 
> You mention the problem only comes up when you climb. Are you downshifting and spinning your way up, or are you mashing your way through? I know you said it's worst in the small ring, but it's still possible to mash depending on your cadence and cog choice.
> 
> ...


The noise is when climbing so in larger Cogs on rear and smaller chain ring in front. The noise is a like bur-r-r-r. I hear the chain meshing with the gears only when there is allot of torque applied riding on the flats and its smooth and quiet. Gear shifting is precise; it jumps up or down to next cog smoothly and not in between. 

I think we can rule out chain length; its is neither too short or to long.

Is there any way to measure wear on front chain rings. I can see some wear but does not appear excessive.

Thanks


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