Cyclocross - STI problems

Seems that Shimano 9 speed Ultegra & Dura ace shifters are prone to failure especially when exposed to particularly dirty environments like a cyclocrosser is. They will shift to larger cogs/rings but will not release to shift to smaller ones. Two questions: Anyone know of a service that rebuilds STI shifters? Did Shimano ever fix the problem?

I haven't heard of a re-build service. Several people I know in Portland claim that 105 is more resistant to grit and the elements in general than Ulltegra or Dura Ace.

You've probably already tried re-cabling with new housings- but if not, try that before chucking the levers. If all else fails, you can flush the lever assembly with teflon chain lube to wash out the contaminents. Once you start putting lubricants in your levers, you have to keep doing it. It will start collecting debris more easily and require flushing more often.

Hopefully cables and housing will clear it for you.

One last thing- make sure your chain and cogs aren't really worn. Worn chains shift late when the shift at all.

There is minimum parts you can rebuild in the STI system. That's one reason I like to go with Campy.

On another note, I agree with Ultegra/105 being a bit more durable....I've had 105/Ultegra equipped cross bikes in the past that I put through hell.. with a through cleaning every once in awhile you should be good.

I froze water inside an Ultegra shifter. When it finally thawed out, it worked okay for a while but eventually siezed up in the halfway position. My right shifter is starting to get a bit clunky, but new housings and cables did make a huge difference, so much so I think I'll replace the rear housings everytime I replace tires.

I've actually found that this can usually be fixed by simply changing the cable tension, may wanna try that if you haven't yet.

my two cents,
Dave

also, if you're looking to perhaps rebuild them yourself you can get parts at http://aebike.com/site/page.cfm?PageID=30&Category=1499