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XTR Front Derailleur Issues
hi all,
having some issues with my front derailleur (XTR e-type). just can't get this thing to behave properly. I have currently adjusted it so it works well enough for the high gears (large CR front, smallest cog rear) and its also fine on the small chain ring.
however on the middle chainring the chain starts rubbing the inside of the FDR as soon as i shift on to the third largest cog on the back
releasing some tension on the shifter (SRAM X0) helps but that in turn means the chain will rub against the outside of the FDR when back in the 3 fastest gears (large CR front)....
plus, about 1/3 of the time it won't even go onto the granny ring. (usually when you really want it to, just before a steep climb) however, when 'helped' on to the small chainring it is perfectly fine. even in the lowest gear.(small front/largest back)
pretty sure it's not an issue with the limit screws as most issues are on the middle chain ring.
obviously i could bring it to the LBS, but would really like to figure this one out myself. in particular because the recent performance of some of sydneys shops have just driven me to replace a rear hub myself. but hey, at least now i know how to build a wheel.
any thoughts on this would be much appreciated.
cheers
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sounds like either the cage is not angularly aligned with the chainwheels or the cage is bent.
I'm not familiar with the e-type mount's adjustability so disregard the following if you can't adjust for twist (unless the mount is bent!).
First check/set-up point should always be height as the outer cage plate clears the teeth of the big ring. Make sure to have about 2 mm gap at the closest point. If you are running a 44 big ring, then the inner curve of the cage will/should follow the curve of the teeth tips pretty well, if it is way off at the back, and really close at the top then raise the mount and rotate the derailleur to the front of the bike.
Put a straightedge on the big ring, look down through the derailleur cage and see how they align to each other? From my experience most derailleurs are more or less parallel sided on the cage and others have a more pronounced taper narrowing to the front. If the cage looks bulbous ie. widest in the middle, then it is likely damaged.
If none of the above seems to be the case, then trial and error trying to determine which part of the cage is rubbing at each stage. Front outside in one case, and rear inside in another would indicate a completely different problem to say rubbing on the spreader tab beneath the chain.
The e-type rotates around the BB. Couple of things to check:
1. Spacers between the BB and der clamp.
2. Top of teeth to underside of cage ~ 1-3mm (already covered above)
3. cage parallel to rings
4. der rotation around the BB
Manual located here:
http://www.shimano.com.au/media/techdocs/content...
Once you've done that, then attach cable, set cage and cable for middle ring, then adjust limit screws for small and big ring.
You might find you have to compromise in the middle ring. Just clearing the chain from the cage when in big cog on back normally means touching the cage when in the smallest one or two cogs on back.
am out on nightride today so can't fiddle with it tonight. but thanks a lot for your recommendations.
it's a scott scale carbon fibre frame, so not sure if there's any adjustment possible where it's mounted to the seat tube. but i'll try all the things you mentioned and then report back.
was actually blaming the sram/shimano combination and already looking for a new FDR but hopefully it's just an alignment issue.
cheers
These days many bikes come with a mixture of shifter and front derailleur brands. It wont be the problem.
I have a Genius which has an e-type XTR FDR and it has performed flawlessly for the last two years. I did manage to smash the cage on FDR and had to replace it however the changes are crisp, one click changes on both front and rear reraileurs. the Genius doesn't use the normal e-type mounting on the BB, instead it has it mounted to a bracket that's attached to/arond the frame pivot and so in place of the e-type mounting bracket on the BB it has one of the three (nylon??) spacers that are supplied with the BB kit. I can select big chain ring and big sprocket or granny with smallest sprocket without chain interferance on the FRD cage however that's not really the best (most sensitive) way to use the equipment!
Gotta say that while I've heard that too about SRAM and Shimano FDs, I'm not so sure about the reality. I have 9-speed SRAM X-7, Shimano LX FD and Truvativ crank on the Rize at the moment, and it was a lot trickier to get right than the all-XT setup on the Jekyll.
On the XT, all you had to do was set up the cage to line up cage correctly on granny ring with the limit screws and no slack in the cable, and middle and big ring would be perfect, same method as setting the rear. Trying the same with the X-7 shifter and it would overshift horribly on both middle and big dog and crunch like a cement mixer full of marbles.
In the end I had to leave the cable set quite slack in granny ring to avoid the overshifting problem. I think the throw on SRAM shifters is just a tad too much for perfect operation with Shimano FDs.
The Shimano website has all of the technical sheets for derailleur's so just print out the one for your model and follow the instructions.
I haven't used Shimano for about a year but the process for XTR used to be:
1. Set derailleur alignment up as mentioned a couple of times above
2. Set chain to small ring and biggest cassette cog then adjust limit screw so chain is almost touching the inside (closest to frame) of derailleur
3. Set chain to big ring and smallest cassette cog then adjust outer limit screw so chain almost touches outside of derailleur cage
4. Set chain to middle ring and largest cassette cog then use cable tension adjuster on the barrel of the gear lever to adjust so inside of derailleur cage almost touches chain
Simple!
I have heard you can't mix certain Shimano with SRAM due to different pull ratio but am not across which models but think 2011 aren't able to be mixed.
30 tooth widgit up front and all your derailleur problems solved ....works for me
http://www.widgit.com.au/
Take it to a shop bud, the Shimano manual will not tell you everything you may need to know. Many shops will not know either granted...
Cheers.
... not sure if anyone still checks this old post, but just in case...
had a busy week and didn't get around to tinkering until today. you guys were (of course) right - the alignment of the FDR was waaaaay out. so thanks to someone posting the link to the shimano page i found the two allen key screws, adjusted them and "......" (insert excitment here) .
from there on it was a piece of cake, set the cable for the middle ring, set the limit screws, and a bit of tweaking on the handle bars - done.
now, just fyi. i purchased the frame second hand about half a year ago and then built the bike up myself. the only items that i didn't put on myself (due to lack of a BB spanner at the time), you guessed it, is the Bottom Bracket and the FDR. because the FDR was installed by a shop i never questioned the alignment and spent ages trying to adjust my gears..
so there you have it - if you want it done right - post it in the forum and do it yourself.
thank you