Replacing SRAM XX chainrings - Quick Check

[kandui]

Bought 2 new chainrings for my XX crank and just want to know what tools I need to replace them. Maybe I can do the job myself.

Do I need to remove the whole crank or just the crank arm on the drive side?

[NINER_boy]

Hi Kandiu

 

You CAN do it all yourself with the appropriate size allen keys... (and a torque wrench)

 

The crank ununstalls EASY (I also have XX, and do ALL my maintenance myself).

 

For the crank, I think it is an 8mm allen key

Just "loosen" the inside bolt, and this will push on the outer bolt, and retract the crank, out.

 

Then replace the rings. The torque for that is 7Nm.

 

Then fit the crank, and tighten the inside bolt to 50Nm.

 

I can mail you a tech manual with this section explained. Just too big to attach on this forum.

Let me know

 

Whoilla, done and dusted.

[NINER_boy]

PS, cannot remember if you HAVE TO remove the whole crank.

 

Wait, will go check quickly...

...

...

...

 

You might get the outer ring fitted, but I think you will have to remove for the inner...

 

Should take you around 35min...

 

Let me know

[kandui]

Hi Niner_boy. Thanks for the advice. When I got home I saw that I could do it with an Allen key. Even the rings come off with a hex key, no Torx key required. Once I got the main crank bolt loosened it was a piece of cake. Another step closer to doing even more maintenance on my bike. Haven't had a chance to test the crank yet, but will go out later this afternoon and see whether I did a good job.

Edited February 18, 2012 by kandui

[Zac.A]

Hi Niner_boy. Thanks for the advice. When I got home I saw that I could do it with an Allen key. Even the rings come off with a hex key, no Torx key required. Once I got the main crank bolt loosened it was a piece of cake. Another step closer to doing even more maintenance on my bike. Haven't had a chance to test the crank yet, but will go out later this afternoon and see whether I did a good job.

 

Hmmm, If you plan on doing maintenance your self then a torque wrench is a must, otherwise you might find your chainrings coming loose during the ride, or...you may have overtightened them.

 

Not saying you don't know what you're doing, just a means of double checking and getting it perfect.

Edited February 18, 2012 by Zac.A

[gummibear]

Even the rings come off with a hex key, no Torx key required.

 

He meant one of these,so that you don't over tighten the bolts.

 

http://www.chainreactioncycles.com/Images/Models/Original/29803.jpg

[kandui]

Thanks for the Pictoral reference, but I do know what a torque wrench is and misred torque for torx in Niner_boy's response

I own a torque wrench, but did not use it t his time.

 

I rode the bike this morning and everything was fine.

 

Another question: My chain keeps jumping off the lower jockey wheel when I ride across rough terrain. I think the chain may be too loose and needs to lose a link or two. I am riding an XX rear derailleur and can't think of anything else which may be wrong. The gear change is fine. Any other ideas?

[NINER_boy]

Hi Kandui

 

Do your front derailleur settings over.

 

I had a similar issue.

Try these steps:

1. Loosen FD cable clamp bolt
   
2. Set inner limit of FD exactrly right (with no cable tension). Change your gears up all the way to 1st (at the back, and check that the FD is JUST not rubbing on the chain when you turn the pedals.
   
3. Turn the FD shifter barrel adjuster all the way in (clockwise), and turn it 1/2 turn out again.
   
4. Hand tighten the FD cable and lock in place with the clamp bolt
   
5. Now, inner limit will be set 100%.
   
6. Next, shift up on the bigger ring (rear in 10th gear, 11t sprocket)
   
7. Set the FD outer limits now that the shift doesnt over shift the chain. In 11T rear and large F chainring, the chain, again, should not rub.
   
8. Now, set the FD cable tension so that the shift is good and immediate.
   

Hope this helps