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I am riding MTBs for over 8 years and either the rules and tools to measure the chain wear do not work or I don't understand how to use them..

I have bought Canyon Exceed with 1x11 SRAM drivetrain. I have been measuring the chain wear and after 1500 km the chain gauge showed .75, which as I understand means, that the chain is worn and need to be replaced, but the cassette should be ok. So I have changed the chain. Well guess what - it skipped on two sprockets. I was shocked. I had the same situation on my 3x9 Drivetrain. there I even tried to change the chain after 500km and the chain skipped on the 2 smallest sprockets. I keep my drivetrain quite clean, and lube it frequently, of course this new bike was always washed and lubed..

I don't know what I do wrong.. I expected that the 1x11 drivetrain will help me to avoid this problem, since all the shifting happens only on the cassette side and not on the chainrings.

Maybe some of you have some suggestions, how I can avoid this problem - next to that will the SRAM x-sync 32 chainring (small aluminium chainring) be worn too if I will put the old worn chain again?

Thanks a lot! Gidi

  • There are many reasons for a chain to skip or jump, other than being worn. And 0.75 is not terribly worn, just worn to the point that it's best to change the chain to maximize cog life. If you're getting skipping, and the cogs are relatively new, the most likely problem is chain length. – Daniel R Hicks May 26 '18 at 19:38
  • I have shortened the chain to exact length of the original chain and since the skipping is only on two sprockets there can be no other reason than the one that those sprockets are worn. I will put the old chain tomorrow and I will see how the things look like, but I know that the day before I have changed the chain everything worked like a charm. – Gidi May 26 '18 at 22:11
  • Note that when matching new chain length to old, you must count links, not simply measure overall (stretched) length. – Daniel R Hicks May 26 '18 at 22:42
  • 1500 km isn't a lot - what maintenance did you do on the chain in that time? Did you ever clean it ? – Criggie May 27 '18 at 2:20
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    I was cleaning it regularly with a rag and then oiling it, when it became very dirty I cleaned completely with degreaser and then added fresh lube. I used only dry lube, since I was driving dry terrain. Replacement sprockets does not exist for the SRAM X1 drivetrain. their cassette XG-1150 is one riveted peace. Thanks for the imput Daniel - I will count the links - this one I overlooked! – Gidi May 27 '18 at 6:42
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The general rule does seem to be 2 chains to one cassette. However, if you ride a great deal on a couple of sprockets they may be worn out more than the others.

Take a good look at the cassette to see if any of the sprockets are worn.

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    How do I recognise if the sprockets are worn? some teeth of the SRAM XG-1150 sprockets are in general very sharp and most of them are different from one another, so i wouldn't know if the form is given or it has changed due to wear. – Gidi May 26 '18 at 22:13
  • "The general rule does seem to be 2 chains to one cassette" sounds unrealistic or i understand it wrong. Lets say one changes a chain after 1500 km. That would mean (theoretically), that i would need to change the cassette twice a season and it cost in my case 120€. I always thought that with regular change of the chain the cassette remains intact for years. What is your opinion on chainring wear? – Gidi May 26 '18 at 22:20
  • @Gidi if you search this site there is a number of answers about cassette wear. – Argenti Apparatus May 26 '18 at 22:34
  • I searched and read many of them, but everyone seem to rely on this measuring system / rule when changing the chain, that's why I dared to question the sense of it, since I seem to have a problem with applying it :) – Gidi May 27 '18 at 6:44
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Don't panic.

Let's suppose you got the correct type of chain, mounted it correctly (aren't 11sp directional?), checked your rear derailleur is well adjusted. Then it is possible that the two suspect cogs are indeed worn. Do look at the cassette from the side and determine if their tooth shape is different from, say, the largest one.

If they are indeed worn, what will now happen is that your new chain will rapidly wear to a state similar to the old one. As now the chain is longer, it will stop skipping over those cogs. You will be able to get some mileage on it, before it hits the 1% mark and become damaging to the front chainring.

If the 2 smallest cogs are indeed worn, I can imagine possible reasons, which have caused it:

  • Very gritty drivetrain. Ruled out in your case.
  • You ride only on those cogs. Like riding a mountain bike exclusively on road. But I doubt 1500km would be enough to wear the cogs with an unworn chain.
  • You constantly overstress those cogs. Like riding standing uphill or somehow managing to drop your weight on only one pedal when landing from jumps. Do think about your cadence when riding.

Also I have heard the rule as 3 chains per cogset and 3 cogsets per chainring. As you see, not too often.

  • As I have read the SRAM XG-1150 chain itself is not direction - only the quicklink is. I have installed it correctly. Derailleur is shifting well. – Gidi May 27 '18 at 6:56
  • From your three assumptions two are pretty close - it is possible that I drive on those 2 cogs most of the time - since I have to cover long flat distances since I get to ride uphill or downhill it is possible that those two gears are my sweet spot. About overstressing - well I like to push a lot. I mean, when I climb a short climb or when I sprint the chain is surely stressed, but as would like to imagine those components should be design for that or am I too naive? My typical cadence is between 70 and 80 and thats where I feel comfortable. – Gidi May 27 '18 at 7:02
  • @Gidi for the cadence I was concerned about some extreme numbers like <50. It seems Criggie's comment is your way out this time. After a couple of years, when your front chainring deteriorates, get a smaller one and you will likely experience more even cassette wear. – Vorac May 27 '18 at 7:35
  • Thank you for your comment! all of you! I have looked at the components and the amount of links on the chain is correct (the same as on the original). the third smallest sprocket is worn - nothing to add on that - i guess I have used it the most. As I have commented to the Criggie's suggestion - SRAM's cassettes for their x1 drivetrain are riveted and there is no way to exchange the sprocket. I have already ordered new cassette - 80€ :( But as a matter of fact I have no idea, how to bike that the new one would last.. – Gidi May 27 '18 at 9:46
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My experience, although not with a 1x11 drivetrain, is that the chain very rapidly adapts and stops skipping. Recently I replaced the chain of my 10-sp Campagnolo Chorus drive train. Initially it skipped frequently, say >10 times per km, on the 17-18-19t cogs, which is my usual comfort zone. After riding in a strong headwind on 21t for about 30 km and return with a tailwind on 15-16t, surprisingly the skipping on 17-18-19 had almost disappeared. After another two 60 km rides the skipping has stopped completely.

I expect that probably next time the chain is worn, say after 5000 km (road bike), the trick doesn't work and I have to replace the cassette.

So my advice is to go out for a ride in which you don't use the cogs that cause skipping. See what happens after that. Perhaps make some intermediate statistics in which you do use the bad cogs and count the number of skips. Might be interesting feedback.

I don't think your chainring will be harmed from this. It will wear according to the actual chain elongation, independent on whether you renew or not renew the cassette.

  • Thanks for your imput. My concern on this approach is won't new skipping chain damage the sprockets? 10 skips per km, 300 skips per 30 km sounds like hell of a damage for a sprocket. but its just my assumption. To tell the truth I havent managed to reach the pont where the new chain stopped skipping, because I also dont feel comfortable biking not knowing - can i put the pressure now or not. But avoiding the damaged sprockets for some rides, may do the trick. I will try! – Gidi May 28 '18 at 16:06
  • I didn't ride 30 km on a skipping sprocket! That would be very irritating. I rode 60 km on sprockets on which the chain did not skip and to my surprise found that the rate of skipping on the most-worn sprockets on which initially skipping was very frequent, had reduced dramatically to near zero. I am very interested in hearing your experience. – mathieu van rijswick May 28 '18 at 20:38

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