Mountain Bike Reviews Forum banner
1 - 6 of 6 Posts

·
Registered
Joined
·
8 Posts
Discussion Starter · #1 ·
Hello, I just finished a build that consists of anXO shifters, XO rear DR, XT front DR, SRAM PG 990 cassette, SRAM hollow pin chain. The rear shifts very nicely through all of the gears except for the 8. On thyis gear it gets very noisy and the chain tries to jump to the 9.

Second problem, On the front of the drivetrain it is very hard to shift to the number three. There are 4 clicks between the 2 and the 3. On the 4th click it gets very tight and sometimes will jump back to the third click. I dont know why.

Thanks in advance
 

·
Registered
Joined
·
2,658 Posts
Well I don't mean to sound flippant or rude, but since I can't see how you adjusted it anything I say will be just a guess and might take longer than if you bought a good maintenance book, took it to an lbs or have a friend who knows how to adjust if for you.
 

·
Registered
Joined
·
78 Posts
My X0 rear seemed a little touchy at first too. Try playing with the "B" tension screw. That fixed the shifting on mine.
Can't help you with the front.
Like Fred said, if that doesn't work, you may want to have a friend look at it.
 

·
(aka SS_MB-7)
Joined
·
924 Posts
juswalk said:
Hello, I just finished a build that consists of anXO shifters, XO rear DR, XT front DR, SRAM PG 990 cassette, SRAM hollow pin chain. The rear shifts very nicely through all of the gears except for the 8. On thyis gear it gets very noisy and the chain tries to jump to the 9.

Second problem, On the front of the drivetrain it is very hard to shift to the number three. There are 4 clicks between the 2 and the 3. On the 4th click it gets very tight and sometimes will jump back to the third click. I dont know why.

Thanks in advance
I've got an identical drivetrain set-up, so hopefully, I can help you out.

To set-up the RD, shift to the smallest cog (9) in the rear and loosen the cable completely. Now, remove your rear wheel and chain and check the frame's RD hanger alignment. Also, check to make sure that the B-adjust was tab is installed correctly. If everything looks OK, move on.

Re-install wheel, but not chain. Stand behind the RD and check the upper pulley's placement under the smallest cog. You'll want to adjust the H-limit screw such that the pulley's center-line with the outer edge of the smallest cog. Then, using your hand, physically push the derailleur up to the largest cog (or as far as it will go). Adjust the L-limit screw such that the pulley's center-line is centered over the largest cog.

Now, adjust your B-tension to get ~6mm clearance between the tip of the cog and top of the upper pulley when the RD is pushed to the largest cog. Check the clearance throughout the cassette.

With the RD installed, you'll need to fine-tune the shifting (this is probably where your problem lies, but it is best to go through everything). Install chain. Make sure shifter is at the lost cog (9). You'll want to rotate the shifter's barrel adjuster to approximately it's mid-point, so you can adjust either way. Tighten RD cable and check shifting by going from 9 to 8 and take careful notice of what the chain is doing. Depending on whether the chain wants to shift or shifted too much will dictate which way you will turn the shifter's barrel adjuster.

1 - Did the chain shift quickly and accurately from 9 to 8? If so, then you are probably within the right range for adjustment. Keep moving up the cassette and then back down, taking note of any lags, chatter, etc. along the way.

2 - Or, did it stay on 9 and not shift. If the chain stayed in 9, then there isn't enough cable tension. Leave the shifter in 8. The chain should sound like it wants to shift up to 8 (i.e., there is chatter). Slowly turn the shifter's barrel adjuster 1 click counterclockwise to increase the tension. Keep turning 1 click at a time until the chain jumps from 9 to 8. You are now very close to the correct tension. Click back down to 9. Then, click up to 8. Did it shift smoothly? Fine tune accordingly. Then, check the entire cassette.

3 - Or, did it overshift into 8 and wants to go into 7? If the chain jumped quickly from 9 to 8 and sounds like it wants to jump to 7 (even though you only clicked it once), you've got too much cable tension. Turn the shifter's barrel adjuster clockwise 1 click until the chatter quiets on 8.

Now, your second problem sounds like one of two things (or both):
1 - your FDs upper limit screw isn't allowing the FD to go up fully onto the big ring, or
2 - your FDs cable tension is too tight, which brings the FD back down.
 

·
Registered
Joined
·
8 Posts
Discussion Starter · #5 ·
Thanks alot for the reply. You were corecton both counts. On the front DR the limit screw wasin fact limiting the movent of the front DR to the point of "overloading" the shifter.

Second, loosed the rear DR cable and was able to adjust the placement so that it was shifting very well. I rode for about 4 hours on Sunday and now the rear DR will not go easily onto the small cog. I am planning on working that out tomorrow.

Thanks again for the help
 
1 - 6 of 6 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top