help needed guys I have XT front mech which has decided it doesnt like to shift down to middle ring but is more than happy to do it from small ring. Everytime I shift from large ring i can hear the shifters index to middle but it immediately drops to the bottom ring. i have followed most instructions on various websites but the damn thing is rebelling. Any one got any ideas? I think i am either retarded mechanically, impatient or something else as this should be a straight forward adjustment. Adjusting barrell either does nothing or turning the other way means I then cant move lever to top ring position unless I force it with a sledge hammer (my thumb is weaker than a toffee hammer so no chance). Could it be a simple case of just cleaning everything out as we have had a lot salt thrown on roads of late?
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 It may be twisted on the seat tube slightly. Check its still seated in its scummy tide marks.
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Its aligned perfectly and the height is ok too. It hits small and big rings ok so limit screws seem fine. i think its just taking the pis$ out of me. Its not that old either, the front mech was replaced about 3 months ago (unsure why but aparently the last one was "bent to fcuk") even though all i was doing was riding along a straight road. Shimano XT has a lot to answer to for that kind of pis$ poor performance.
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Okay, this happened to me once. I got the cable routing slightly wrong, trying to pull the derailleur from the bottom rather than routing the cable over the top.
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Update: Not sure what piece of fettling or tweaking did it but last night i managed to get all gears working. Its not slick and as fast as i would like but it aint bad. It seems it had a trick up its sleeve where by i had everything set pretty much ok but in the work stand it wouldn't work but when i actually went out on it it was ok, i guess putting a bit of load on helped. tricky little devil this front mech. On a seperate note i did notice that i couldn't move my front mech by tugging on the cable at the top tube yet on other bikes the mech moves freely and easily. I have cleaned it as best i can and then smothered it in GT85 overnight and today it moves but its still stiff, any ideas or is this normal?
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 How old is it? Could just be knackered?!! Slacken the cable off and try moving the mech with your hands to see if it is the mech or the cable. Give everything a damn good clean. A drop of oil on the mech's pivot points and on the cables might help. Make sure to wipe any excess oil off, to avoid attracting unwanted dirt/grit etc...
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 It sounds like your cable routing may be off to me. If the cable run comes down toward the mech then it should run under the top pulley & up to the securing bolt. If you've gone straight or the cable isn't seated on the pulley then it may explain your problem. HELP? Sticking cable or shifter may also be the issue.
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| Edited: 26/02/09 22:55 |
I'd say its worn out, pivots are fecked, I have one just like that, or did. I drilled out the pivots and put a stailess bolt throgh from one side to the other .
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Pivots are always overlooked on a front mech, but I can't help coming back to the cable routing. Keep us updated, I'd be very interested to know what's at the bottom of it.
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Well front mech was working fine this morning again, i think a good clean out of the mech and a good overnight oiling seem to have eased the mechanism. i think that probably did more good than the fettling of the cable and adjuster. To answer a few of your queries. its unlikely the front mech is/was worn as its only 2 months old. The bike itself is just less than a 1yr old Merlin Malt so may be a little cable stretch in there. Cable routing is fine as Merlin built it and it hasn't changed when new front mech was put on. All in all i reckon it was more down to sticky cable and front mech probably due to all the salt and crap on the roads of late. May be a little tweak to the cable helped a little. Cheers everyone for the advise, much appreciated.
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