SRAM indexing

velvetytoast

Hi all,

I've need to have a play with my SRAM Rival as the shifting into the big three rings on the rear deraillur seems to be having a few problems. Basically:

On the big ring on the front I can shift down to all but the largest ring on the back ok
On the small ring on the front I cant shift any further down than the 3rd largest ring on the back (after that the shifter clicks but the chain won't locate on the next ring down)

I've tried adjusting the low limit screw and it seemed to be ok but after about 30 miles today I was experiencing the same problems again

Any ideas?

Thanks in advance

sungod

cross-chaining - big front, small rear, and vice versa, is not a good thing, causes extra wear, but on the small front ring you should be able to go to smaller at the rear

from what you describe, the tension is probably wrong

this shows youy how to adjust front and rear...

http://www.sram.com/_media/techdocs/95- ... lleurs.pdf

btw the limit screws are only to set the extreme limits of derailleur movement, make sure they are correct or you can shift the chain off, if this happens at the rear on the largest cog it can damage the spokes

velvetytoast

Thanks for the link - managed to print it out in A3 so I can read the writing - will have a play around this weekend (being careful of the limit adjustments of course)

onbike 1939

I think that if you have been using your bike in this weather, a far more likely cause is that salt and muck are preventing the RD from operating over the full range of movement. Give all pivot points on the RD a good dose of WD40 or something similar. Now, lifting the rear of the bike of the ground and rotating the pedals, change gears back and forth until the arc of movement enlarges. It may be that you have to lube the gear cable also. When the gears are changing correctly, lube all pivot points on the RD.

velvetytoast

I'll make that the first thing to do before any tweaking - thanks again!!

gregg.pedder

Check the rear mech hanger and derailleur cage. If either is bent it might give the symptoms you describe. Sounds awfully like something is bent or out of alignment.

Also check the alignment of the rear wheel. Ensure it is centred in the frame and the QR is tight.

If the rear mech cage is bent i do believe they can be straightened but a new Rival Rear Mech is only about £55-60.

Hope this helps.

GP

lewishamilton

I had that problem setting up my Rival last week (biggest front cog, and RD wouldn't shift to the largest rear cog).

It was solved with the barrel adjuster on the RD. Turned it anti-clockwise a few times. Works a treat now.
Limit screws are to stop the chain being thrown into the spokes or onto the chainstay.

ADIHEAD

Hey Lewis, hope you're all geared up for the new season? Word to the wise, Jenson's been off training with Lance so hope you've been working hard on the pre-season fitness