SRAM XX chain length

[Rubel]

Have just collected my bike from my LBS having done a major service before the Epic.

 

My bike has 2x10 SRAM XX drivetrain.

 

They have put a new chain on and it seems too long. When it is on the small ring in the front and the small cog at the back it is very loose with the top of the chain actually resting on the chain stay and the bottom sagging significantly. The guys at the shop say this is how it is supposed to be.

 

Any similar experiences or advice please?

[LazyTrailRider]

Hmmm, I don't run XX myself but that doesn't sound correct.

 

Generally, on most setups (I run 3x9, so this could be completely different) I've always used the rule-of-thumb that when on the big ring in front and the small cog, the pulleys are directly vertically aligned. Is that the case with yours?

[kennyg]

10 speed is a little different... from Martin's comment

 

My advice:

 

1. Walk into the bike shop, and ask them if they have common sense.

 

2. I do...Big ring front, Big cog at the back plus 4 links. A long cage mech should be able to take all the slack, a mid cage may need or dual sus may require an extra link short/extra depending on the setup.

 

 

Small ring and small cog, should have the cage close to full retraction, big ring and big cog at the back should give you quite a good pull forward on the cage.

[LazyTrailRider]

Logical advice, Kenny. I'm assuming with 10spd there is a smaller spread between extreme ends, hence the difference.

 

"Close to full retraction" on small/small makes sense, but definitely not more than full retraction as seems to be the case here...

Edited March 22, 2011 by Martin Hattingh

[grumpy]

I noticed the same thing on my bike on Saturday, the chain started rubbing against the deraileur cage, think the settings needs to be adjusted, when I went to the small chainting and the small gear in the back the chain was rubbing on the cage.

The chain is actually hanging and is a bit loose.

 

I never noticed this before as I normally don't use the small chainring much, have never used both at the same time. The chain is due for replacement and is a bit stretched, I had a look the rear deraileur should be able to handle it if I remove one link, will check tonight

Edited March 22, 2011 by grumpy

[kosmonooit]

From the SRAM doc for 9 speed PG991: chain over both big rings bypassing RD then add one complete link. I assume the same for XX 10 Speed ... if you have a power link just take off the chain and check it out for yourself (or is the link they used for XX the use once only type as 10 speed SRAM road?)

Edited March 22, 2011 by kosmonooit

[The Drongo]

Dude, the chain is like a COMPOOTER. It only does what you tell it to do. It does not know it is on a 10 speed setup.

 

Chain over LARGE front CHAINRING and over LARGE rear Chainwheel. leave the derailleur out for now. Add 1 full link and 1 1/2 link for Med cage derailleur, and 2 full links and 1/2 link for Long cage.

Final check, once threaded through th the RD, is that the jockey wheels should sit almost parallel when the chain is on the SMALL front and small rear. One part of the chain should not be touching the other (for High normal derailleur)

If Rapidrise then the cage should be roughly 90degrees to the chainstay.

 

Oh - remember to pack 10 speed links. Most of us muppets passing you wont be able to help if you 'Schnap' it. We all on 9 speeeed.

 

Forgot - most of the LBS laaitjies are not like COMPOOTERS. They seldom do as they are told, and can't remember a thing. Although they apparently crash often.

Edited March 22, 2011 by The Drongo

[Rubel]

Thanks guys

[grumpy]

Hi Rubel

 

I replaced my chain last night, with the gears selected on the small chainring and the smallest gear the chain misses the bottom of the front derailer (barely), there is no way of shortening the chain further, the powerlink requires that you remove 2 links and that would make the chain too short.

 

Bootom line is accept that you should probably not use the small gear with the small chainring and expect no chain rubbing.

[manbearpig]

Thats why I do my own maintenance, the "guy at the shop" needs a running &%slap. Hope you sorted Megan's bike out too....