FD Shifting Problem



OCRoadie

New Member
Oct 5, 2004
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I need some help. Over the the last weekend I tinkered with my FD (F#cked up my front deraileur). It started when I swapped my rear cassette from 12/25 to 12/27 and installed a new chain. After the swap, I was getting more than usual chain rub on the FD. I made minor adjustments to the FD limit screws and all was good. On Monday I swapped back to the 12/25 cassette and had similar chain rub issues. I tried making similar adjustments to the limit screws as before. Minor adjustments quickly became major adjustmets and the whole FD was way out of whack. I did the whole drill on the Park site (loosened cable tension, reset inner and outer limit screws and readjusted tension). Everything was looking and shifting good without a load. As soon as I test rode the bike, the shift from the 39 to the 53 was terrible (maybe 10 revolutions before shiftin, if it would shift at all). I took the bike to a LBS on Tuesday and the mechanic did the same drill that I did, with the same results, maybe slightly better. I noticed this morning that if I "double pump" the FD shift lever, it shifts much faster. I have to move the shift lever like I normally would, then release it back and quickly move again to the shifting position with quite a bit of pressure. Any thoughts, tips, suggestions on what to look for or try? The chain is brand new and the mechanic at the LBS checked out FD position and chain ring condition, everything looked good. The drive train is all DA 10spd, and always shifted beautifully unitl now. I will probably take it the shop that built it for me, but they're 45 minutes away, so that's my last resort. Thanks for your help (I hope :)).
 
OCRoadie said:
I need some help. Over the the last weekend I tinkered (F#cked up my front deraileur). It started when I swapped my rear cassette from 12/25 to 12/27 and installed a new chain. After the sway, I was getting more than usual chain rub on the FD. I made minor adjustments to the FD limit screws and all was good. On Monday I swapped back to the 12/25 cassette and had similar chain rub issues. I tried making similar adjustments to the limit screws as before. Minor adjustments quickly became major adjustmets and the whole FD was way out of whack. I did the whole drill on the Park site (loosened cable tension, reset inner and outer limit screws and readjusted tension). Everything was looking and shifting good without a load. As soon as test rode the bike I the shift from the 39 to the 53 was terrible (maybe 10 revolutions before shiftin, if it would shift at all). I took the bike to a LBS on Tuesday and the mechanic did the same drill that I did, with the same results, maybe slightly better. I noticed this morning that if I "double pump" the FD shift lever, it shifts much faster. I have to move the shift lever like I normally would, then release it back and quickly move again to the shifting position with quite a bit of pressure. Any thoughts, tips, suggestions on what to look for or try? The chain is brand new and the mechanic at the LBS checked out FD position and chain ring condition, everything looked good. The drive train is all DA 10spd, and always shifted beautifully unitl now. I will probably take it the shop that built it for me, but they're 45 minutes away, so that's my last resort. Thanks for your help (I hope :)).
DURA ACE 10 speed chains seem to be particularly fussy.
Make sure the chain is not worn and that it is clean.
Also make sure that shift cable and housing are clean and not worn. Pay particular attention to the cable under the bottom bracket and the cleanliness and profiles of the chain rings.
 
Hmm... assuming you've checked the entire cable line for things that could gimp it (a cable end cap out of its ferrule, etc) did you try a small turn on the H limit screw?
 
RC2 said:
Hmm... assuming you've checked the entire cable line for things that could gimp it (a cable end cap out of its ferrule, etc) did you try a small turn on the H limit screw?
Myself and a mechanic checked out the whole line from shifter to FD. The H limit screw is about as far out as I would set it. Also, chain and chain rings are clean and in excellent condition. I was hoping the bit about "double pumping" the shift lever might be a tell-tale of the problem to some of you more experienced wrenchers. Thanks for the advice from both of you, I'll see if anyone comes up with something that I may have missed.
 
The limit screws only set the limits for the range of motion for the FD.

Sounds like your FD cable doesn’t have enough tension. When you do get the cable tension correct, and your limit screws are way out of adjustment, you may shift the chain right off the ring gear.