I have a new low-normal xt rear mech which is currently ghost shifting in certain gear combinations (14-44 seems to be the worst). anyway, its very annoying and dangerous because it could cause me to greviously injure my groin if the chain slips. has anyone any suggestions on how to fix this? i have played around with the adjuster on the back of the mech which works for a while but then it starts its old tricks again. it seems to be at its worst after a long, steep climb and then on the downhill its starts to shift in and out of about three different gears. any suggestions would be much appreciated as both my LBS's are worse than useless at anything other assembling kiddy's tricycles, they refused to touch my bike when i brought it in!

Check the cables, especially how the housing sit in the cable-stops. (Think they are called that.) If the bike is new, then that is probably the cause of the ghost shift.

Do you think it will go away in time if i keep adjusting it??

make sure the cables travel freely and quickly, especially when the cable is moving in the "slack" movement, or in other words, when the spring of the derailure is moving the cable. also, check to see that all the wheels of the derailure are running parralled to each other. Last gost shifting I has was because the bottom wheel in the derailure was bent just a little out of line. Just before a race! bent it straight by eye and didn't miss a shift the whole race.

I had this happen in the same gear combination on my MTB. It truned out that my derallieur hanger was out of alignment. I ended up buying a Park hanger alignment tool and after tweaking the hanger, the bike shifted perfectly. The tool was about $40, so you might want to just bring it into a shop instead of buying one. Of course,this might not be your problem at all, but I have checked a lot of friends bikes and found the hanger to be misaglined. Like the others have suggested though, make sure the cables and housing are clean and that the shifter cable is sliding through the cables smoothly. Good luck.

I will almost guarantee the derailleur hanger is bent if the 44/14t is the worst combo.

If you find yourself repeatedly adjusting the cable tension, check all of your cable stops. Sometimes the cable housing tries to shorten itself. What you are looking for is one or more of the tiny cable housing wires sticking out.

Just for my own information, how do you like that low-normal derailleur? I absolutely despise the C-101 and C-201 stuff, but I don't have any experience at all with the better quality low-normal components.

Bent hanger or improper cable routing with a dual suspension frame.

Does the shifting occur whey you stand on pedals (I.e. frame twisting?), or after you have spent some time on a given gear (i.e. derailleur slowly shifting), or after you have upshifted or... ?


Apart from above suggestions, here are a few :

- Check if the spring inside the derailleur is jammed with crap or severely rusted. The derailleur should be able to move freely under spring tension.
If necessary, flush the derailleur spring clear with WD-40 (with the straw) and re-lube.

- Check that cable isn't kinked anywhere along its length. A kincked cable won't move as well and would provide very late shifting.

- Check indexing close to the largest cogs. Since the upper pulley has some built-in lateral play, try to backpedal and see if it remains in the middle of its zone.

- Check the tension screw where the cable enters the derailleur. Believe it or not, I once had played so much with it that it was unscrewed out of the derailleur. It didn't look bad because cable tension kept it in place, but it also meant very unreliable indexing. Try to wiggle it; if you can move it sideways, you need to screw it in place.

All good suggestions. It could also be due to trail debris that is packed between the cogs and preventing the chain from seating properly. Chains with stiff or twisted links can cause this problem and it is generally more noticeable on the tighter raduis of smaller cogs. Chain problems are easily detected by watching the chain travel slowly over the jockey and tensioner pulleys. Good luck!