Bicycle Mechanics - Broken shifter??

I have a Dura Ace 9-spd and it no longer shifts into the big chainring (double) using the shifter. When I manually pull the cable on the downtube, it shifts just fine. H/L limit screws seem to be set perfectly. I removed the front derailleur and it seems to be functioning perfectly. When I attempt to shift however, the derailleur only moves outward slightly (maybe 1/4"). The "fixing bolt" is securely holding the cable, and the cable is taught. I'm perplexed. My only remaining guess is that the shifter is dead. No idea how the internals of the shifter work, so not sure how to confirm. If bad, are they generally repairable? It sucks being stuck in the small ring! Any help is greatly appreciated!! Thanks

I have a Dura Ace 9-spd and it no longer shifts into the big chainring (double) using the shifter. When I manually pull the cable on the downtube, it shifts just fine. H/L limit screws seem to be set perfectly. I removed the front derailleur and it seems to be functioning perfectly. When I attempt to shift however, the derailleur only moves outward slightly (maybe 1/4"). The "fixing bolt" is securely holding the cable, and the cable is taught. I'm perplexed. My only remaining guess is that the shifter is dead. No idea how the internals of the shifter work, so not sure how to confirm. If bad, are they generally repairable? It sucks being stuck in the small ring! Any help is greatly appreciated!! Thanks


Loosen the limit screws to make sure this isn't the problem.

You could try flushing the shifter out with WD40. Sometimes the grease Shimano uses gets hard and will cause shifting issues. Other then that, there isn't a whole lot you can do. They aren't repairable and basically are throw aways when they break.

Another "fix" is that there is a three year warranty on Dura Ace components so, if your shifter is with in that period, you can get a new one under warranty.

As Ray said, Shimano STI shifters aren't repairable and a solvent wash and relube is about all you can try.

Dang. Just tried WD40 with no luck. Also checked cable routing & it looks fine. Limit screws are set perfectly, as shifting is flawless when done via manual tension on the cable at the downtube. The shifter seems to travel its normal distance, so I'm guessing that something inside is broken rather than just jammed. Unfortunately I'm not the original owner of the bike or shifter, so it sounds like the Shimano warranty is likely void? It may be past 3 years too since it's an '03 model bike. Bummer. I guess that's what I get for buying used off eBay (only 4 weeks ago too).

Bingo! I figured it out (with the help of my LBS mechanic). The problem was, in case anyone is interested, that I failed to install end caps on the cable housing when replacing it last week. The housing's wires were exiting the housing on one end and wreaking havoc. [note to self: DON'T FORGET THE END CAPS NEXT TIME!!!]

Thanks for all your helpful suggestions!