2x10 question

[blholtz]

Has anyone with a 2x 10 had a problem with the chain grabbing the large ring while in the small ring and the two smallest cogs on the cassette?

If so what (if anything) did you do to fix the problem?

[Hudnut]

I've had not problems but is sounds like your chainline is off. driveside of crank may need to be moved outward a tad.

[irishpitbull]

What length of derailleur are you using?

[blholtz]

It's a x9 rear dérailleur. But I have no idea on length.

All parts are original on the bike. Lbs found a little slop in crankset once that was shimmed up the chain grabbing started. Thought maybe another shim might move crank out and take care of it, but mechanic at lbs said it was moved to far for proper crank engagement on left side.

[DRC]

I have not had the issue but chain line, like Hudnut said, would be my first guess. To be honest, I don't follow your comments from the mechanic - I would think you would want to shim the drive side. Does it happen randomly or during a certain type of riding like really bumpy/rocky sections?
Is the DT all SRAM X9?

[blholtz]

It happened in the parking lot of lbs. they didn't have time to dig thru it. It's a warranty thing.

I stay away from those gears while on the trail so as to not haveit happen at a bad time.

They want me to leave it so they can figure it out.

The mechanic said if they put a shim on crank it would move the crank to far to the right and make the crank arm engagement to thin. Doesn't sound right to me either, but i dont know what kind of tolerances they r working with either.

I thought about putting a smaller chain ring on it, I think that might help. It's a 38 tooth on there now.

[blholtz]

Sand yes I think it's all SRAM x9

[Hudnut]

what type of BB is it?

[blholtz]

That I am clueless on. It's on specialized epic if that helps.

[Jerry68]

Find a better mechanic.

[jgrayson]

Actually, this has been a common problem with 2x10 drive trains. SRAM hasn't made this public because of fear of backlash, but you are not crazy. I have a few friends who have had the same exact problem. Constant chain suck is driving people crazy. In some cases, SRAM has upgraded the components to XX. The main fix, however, has been to go to a rear derailleur with a small cage!! I know this sounds crazy, but I can get you in contact with someone who has had the exact same problem if you IM me. It is not a chain issue or a problem with your crankset, apparently, by increasing the tension with a smaller rear derailleur, the problems have been eliminated.

Good luck with your resolution. All I can say is be persistent, and you will get the problem resolved.

[blholtz]

Thanks for the info. I will be persistent with it, I like the 2x10 other than not using the two small cogs while in the small chain ring.

Would a smaller cage also prevent the chain from rubbing on itself when in small chain ring and smallest cog in the cassette. The cage rolls under to keep tension so much that the chain line coming backwards toward the cassette rubs on the chain section running thru cage.

Didn't think both problems were related but I think they might be.

[jgrayson]

I double checked, and SRAM recommends a medium cage. If you check their website that's what they recommend. Not a small cage. If I'm not mistaken, most bikes are stocked with long cages. This has worked for other people, so good luck.

[blholtz]

Ok thank you very much. I will take this info with me to lbs and hope it speeds up the process.

I'll let u know how it turns out.