# I put on new chain. Now skipping teeth under load...



## jeff400650 (Mar 29, 2014)

Trek Domane triple with new chain and chainrings installed by LBS 1500 miles ago. I just installed a new Sram 10spd chain today. It the first time I have ever done this myself. All went well. Pretty positive that I sized the new chain properly. Shifts into all gears, including big/big and small/small. But when I put any significant force into the pedaling, it skips a tooth, seemingly on the chainring, as opposed to the cassette. It will do it on any of the 3, but is easiest to induce on the smallest. The cassette is pretty new too. All gears look new, no visibly worn teeth.

Did I do something wrong? What gives?


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## Sumguy1 (Apr 5, 2008)

Did you use the SRAM quick link ( or whatever they call it?) 

Are you sure it's set and locked into place? You have to give it a good effort to lock it. 

That's the first thing I'd check. I have seen "unlocked" powerlinks? jump and click.


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## jeff400650 (Mar 29, 2014)

Yes. Good call, but that is not it. I actually did rotate the chain on the work stand with the link not set just to verify that the length was good, and it chinked through the gears a bit, but once everything looked good, I put some force on it, and it clicked into place. Then I went out and rode the bike for a couple laps in the driveway and discovered the skipping teeth situation. It really is a mystery to me. Everything looks perfect.


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## askmass (Sep 28, 2009)

jeff400650 said:


> Yes. Good call, but that is not it. I actually did rotate the chain on the work stand with the link not set just to verify that the length was good, and it chinked through the gears a bit, but once everything looked good, I put some force on it, and it clicked into place. Then I went out and rode the bike for a couple laps in the driveway and discovered the skipping teeth situation. It really is a mystery to me. Everything looks perfect.


I'd suspect the cassette, but check the hanger and cables/tension first. 

This happened to me a couple times early on and in both instances it was me waiting too long to replace the chain and chewing up the cassette just enough to where it would skip under load with a new tight chain... I'd put the old chain back on to verify, and the skipping was removed. A new chain can expose even slight cassette over wear. 

So, I've found it better and cheaper to replace chains early and preserve cassettes. Some people even rotate a couple chains to really max out the longevity. The little Park Tool chain checker is good to have and I use it every couple weeks during regular maintenance.

Good luck.


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## Lombard (May 8, 2014)

askmass said:


> I'd suspect the cassette, but check the hanger and cables/tension first.
> 
> This happened to me a couple times early on and in both instances it was me waiting too long to replace the chain and chewing up the cassette just enough to where it would skip under load with a new tight chain... I'd put the old chain back on to verify, and the skipping was removed. A new chain can expose even slight cassette over wear. Keep in mind that your chain and cassette eventually "marry each other". A new chain will not mesh well with a worn cassette.
> 
> ...


This is exactly what I first suspected until the OP mentioned the skipping is on the front. OP, are you absolutely sure it's happening in the front? It's really hard to tell just by feeling.

Another problem besides a worn cassette could be a sticking link. A link that is not free will jump as it moves through the derailleur pulleys.

And just covering all the bases here. Did you install the correct chain (10-speed chain for 10-speed drivetrain, 11-speed for 11-speed, etc.)? It is also a good idea to match the brand of chain with the brand of cassette you have. There are very subtle differences.


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## Easyup (Feb 26, 2012)

If you used the same number of chain links and it runs smooth on the stand with our family's bikes anyway it most assuredly is the cassette. It always feels like it is in the front but one or more cogs is too worn for the new chain. You mentioned it does it with all three chainrings, what about all 10 cogs? You can reinstall the old chain and the problem should disappear. Cassettes are tricky to assess visually.


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## wim (Feb 28, 2005)

jeff400650 said:


> I actually did rotate the chain on the work stand with the link not set just to verify that the length was good and it chinked through the gears a bit...


Try taking the the link off and putting on a new one. Shifting through the gears with the link's locking clip not set could well have mangled the link (pins no longer parallel) to the point where it kicks up under power.


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## redondoaveb (Jan 16, 2011)

Lombard said:


> This is exactly what I first suspected until the OP mentioned the skipping is on the front. OP, are you absolutely sure it's happening in the front? It's really hard to tell just by feeling.
> 
> Another problem besides a worn cassette could be a sticking link. A link that is not free will jump as it moves through the derailleur pulleys.
> 
> And just covering all the bases here. Did you install the correct chain (10-speed chain for 10-speed drivetrain, 11-speed for 11-speed, etc.)? It is also a good idea to match the brand of chain with the brand of cassette you have. There are very subtle differences.


Didn't know KMC made a cassette.


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## jeff400650 (Mar 29, 2014)

Thanks for the great help, everybody. I put the stock rear wheel and cassette on to test. It has only few hundred miles on it. That solved the skipping, so I guess it was not such a mystery really, just a worn cassette. I guess the one I was using does have about 3k miles on it, but it looks fine to me. Hard to imagine that the chain would be able to lurch past teeth like that. I will put a new one on my preferred wheel and all will probably be fine. I am for sure going to keep records of component changes going forward, so I know the exact mileage on parts. The profile section on Strava has a components segment for each bike that is perfect for that.


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## Lombard (May 8, 2014)

jeff400650 said:


> Thanks for the great help, everybody. I put the stock rear wheel and cassette on to test. It has only few hundred miles on it. That solved the skipping, so I guess it was not such a mystery really, just a worn cassette. I guess the one I was using does have about 3k miles on it, but it looks fine to me. Hard to imagine that the chain would be able to lurch past teeth like that. I will put a new one on my preferred wheel and all will probably be fine. I am for sure going to keep records of component changes going forward, so I know the exact mileage on parts. The profile section on Strava has a components segment for each bike that is perfect for that.


Looks can be deceiving. Sure, "shark finning" is an obvious visual sign your cassette is worn, but you can have problems well before this point without any obvious visual cues.

3,000 miles on a single chain can wear your cassette to the point of problems when you install a new chain - with the emphasis on CAN. It can depend on a number of factors.


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