sram x-9 b adjust problem...

[bikerzim]

I went to install my new x-9 rear derailleur and noticed it has a different b adjust mount.... no problem I mount it, but when I try to adjust it to the specs on the installation instructions, it is non linear from the smallest cog to the largest cog... I have a new pg 980 9 speed cassette. I can only get close to the specs on the largest ring.... nowhere close on the small cog... I think the problems is from the new design of the derailleur.... has anyone else ever encountered this? I have changed many sram derailluers on this bike, but this is the first time I ever had a problem.... anyone have any ideas?

[Slappy]

Have you tried runing it yet? In 20 years home wrenching mtbs, I've never even looked at a derailleur spec; personally, I wouldn't worry about it too much. YMMV.

[adrnalin69]

Explain what you mean when you say "spec"? The alignment? The distance from top pulley to cog? Or chain length?

[bikerzim]

slappy, I haven't yet tried it, I need to run up and get a new shifter cable... mine is frayed and needs replacement and too dang wet/windy outdoors.

adrnalin69, when I am in the largest rear cog the distance between pulley and cog is about 6mm, but the smallest cog to pulley distance is about 20mm. I believe SRAM recommends 6 mm each.

[C.P.]

Yeah, what he said...'doesn't seem like it could be a big deal, maybe the manual has a misprint...usually I make B screw adjustments and only check that the upper pulley isn't coming into contact with the largest cog (swinging suspension through full arc if a fully) and fagetabout any B screw changes WRT the small cog...

The only other thing that comes to mind, is make sure there's enough play in the cable housing so it doesn't bind up the der...

[smelly]

Make sure it's ok below the big cog and you're good to go. No need to worry about how far the derailleur sits below the little cog. Sounds like a manual misprint to me. If not, I'd be curious to talk to a SRAM tech and find out out just how one goes about adjusting how the derailleur sits below the smallest cog.

[bikerdom]

Be sure the chain length is correct. Per Srams instructions: Wrap the chain around your big ring and big cog on the cassette without going though the derailleur. Where the links meet add two links and there's your chain length. SRAM wants 1 to 1-1/2 links distance between the cassette and top pully while turning the cranks backward while in the largest cog and smallest front ring. Works everytime for me. Don't worry about the small cog so much.

[adrnalin69]

All good suggestions. I am happy that so many non-mechanics are this concerned with what the manual says. In fact I am amazed that people are looking/reading the manual at all. Kudos to you, Home Mechanic, you deserve a beer.

[bikerzim]

Just as a follow up. I adjusted it to the large cog and ran it thru the gears, seems to shift crisply. I will take it out around the house tomorrow to see how it does under load. Thanks for all the input. Just a side note: The derailleur is different from the previous derailleur, the cable run is inward, versus outward and the b adjust is missing a piece that goes against the hanger.

[thomllama]

Just as a follow up. I adjusted it to the large cog and ran it thru the gears, seems to shift crisply. I will take it out around the house tomorrow to see how it does under load. Thanks for all the input. Just a side note: The derailleur is different from the previous derailleur, the cable run is inward, versus outward and the b adjust is missing a piece that goes against the hanger.

yup,those are the new ones, little better. they moved the cable mount inside because people were getting sticks and crap stuck on it, little harder to get the cable tight I think but worth it in the long run,..

you get the version with the jockey wheels are hollowed out some? not solid? if you did you'll notice they run a LOT smoother, cause they are actual bearings now not little bushings on plastic.. big wear +!!

like everyone said, just adjust to largest ring.

One other thing to watch, the cable housing and the cable it's self come in now at a slightly diff angle, watch as you go through the gears at the cable end and make sure it's not kinking or bending the cable to sharply coming out of the housing end and heading toward the black loopy guide thingy..(what ever they call it) . you might have to slightly lengthen the cable housing... It might save you from some weird ghost shifting

[ktmdad]

Issues and differences with the new X9 RD have been discussed on MTBR as well. There may be more.

Here are a few links.

http://forums.mtbr.com/showthread.php?t=546381

http://forums.mtbr.com/showthread.php?t=575854