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Discussion Starter #1
OK, so I have a fairly new XX drivetrain on my niner air 9. The components have less than 500 miles. Occassionally, the chain will skip on me. I thought that maybe the chain was the issue, so I replaced it with a new 1091R chain. I took it out today, and over a 25 mile road ride, the chain skipped 3 times. It bothers me, because I'm afraid that it might skip at a bad time, like when I'm climbing hard, and could cause me to crash. I'm not sure what could be causing this. Does anyone have anything I should check?
 

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Former Bike Wrench
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Is it an actual skip or possibly a ghost shift from cable housing being either too short or too long and it moving the derailleur enough to feel like a skip. This can me a common problem on full suspension bikes as the housing is often cut when the frame is in the stand and suspension movement is not taken into consideration.
 

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Discussion Starter #3
I believe it is a skip (not changing gears). The bike is a hardtail, and the cable/housings are new.
 

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The Punk Hucker
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3 times in 25 miles isn't so bad that I suspect this occurs in a particular gear combo. Am I right?

Did you check your cassette and chainrings for wear?

It's not impossible this will get fixed as the chain settles in but expect to replace at least chain+cassette (and possible chainrings) the next time.
 

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Discussion Starter #5
Holy Crap. I didn't think I'd have to change out the cassette after only 500 miles. These XX cassettes aren't cheap.
 

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I suspect its the rings. A few guys from our shop have had to replace rings. After overhauling my BB yesterday I took a good look at my XX rings and I think I might be in the same boat. The small ring is pretty reasonable, around $25, but the big ring is over $100.
 

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Discussion Starter #7 (Edited)
That sucks. I can't believe that I should have to replace the big ring after only 500 miles of use. It really doesn't look worn down at all, so I am a little skeptical that this is the real issue causing the chain to hop occcassionally.
 

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The Punk Hucker
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I have damaged chains & cassettes in 500 miles in bad conditions. Where do you ride?

The biggest cog on the cassette is aluminium and will wear much faster, does your skipping happen on the big cog?
 

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Discussion Starter #9
I ride on Michigan trails and roads. I'll have to try riding in the little ring for an hour to see if it still skips. The big ring looks fine to me, I really can't imagine that this is the issue. I have nearly 10K miles on my road chainrings with no issue.
 

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The Punk Hucker
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dougmint said:
I ride on Michigan trails and roads. I'll have to try riding in the little ring for an hour to see if it still skips. The big ring looks fine to me, I really can't imagine that this is the issue. I have nearly 10K miles on my road chainrings with no issue.
Road bikes don't see much mud and always last much longer because of it.
 

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Discussion Starter #11
If I have to replace the XX cassette and large chainring every 500 miles, I am going to be dropping $400 every 2 months this year.
 

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It may be a long shot, but I'll throw it out there anyway. Think it's the new chain? I've had a new chain that never shifted great, even after a few rides. Another chain solved the problem.
 

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dougmint said:
If I have to replace the XX cassette and large chainring every 500 miles, I am going to be dropping $400 every 2 months this year.

SRAM really does thank you for this too.
 

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I have noticed that on 10sp mtb drivetrains things have to be REALLY dialed in. If you even a tiny bit off it's enough to cause the chain to jump, skip, or ghost shift. I have seen this happen on brand new bikes. 99% of the time it's an adjustment issue. You just dont have the room for error that you did with 9 speed.

With XX everything starts at the high limit screw, if that's off even a little bit then the cable tension compensates for that on the first few shifts, but as you go up the cassette your being a tiny bit off continues to add up despite XX being 1:1. I saw this in 9sp XO but it was very rare, and you has to be way off on the high limit to screw things up, 10sp XX has to be that much more precise
 

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Discussion Starter #16
rlouder said:
It may be a long shot, but I'll throw it out there anyway. Think it's the new chain? I've had a new chain that never shifted great, even after a few rides. Another chain solved the problem.
I don't think it's the new chain, as the whole reason I bought the new chain is because the old chain was skipping, and I thought the new chain would help.
 

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Check the hanger too. Might as well look at every adjustment option before spending $.

XX is well known for going through chainrings. That said, a number of people who have had multiple chainring replacements have not yet worn out either the chain or cassette.
 

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surlyboy said:
I have noticed that on 10sp mtb drivetrains things have to be REALLY dialed in. If you even a tiny bit off it's enough to cause the chain to jump, skip, or ghost shift. I have seen this happen on brand new bikes. 99% of the time it's an adjustment issue. You just dont have the room for error that you did with 9 speed.

With XX everything starts at the high limit screw, if that's off even a little bit then the cable tension compensates for that on the first few shifts, but as you go up the cassette your being a tiny bit off continues to add up despite XX being 1:1. I saw this in 9sp XO but it was very rare, and you has to be way off on the high limit to screw things up, 10sp XX has to be that much more precise
I agree, after setting up and working on my brothers XX drivetrain. The alignment and tension had to be perfect, or there was some skipping/jumping in one area(of the cassette) or another.

This sounds like the OP's issue - get that drivetrain dialed in.
 
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