Bicycle Mechanics - Ultegra Brake lever shifter missing shifts

I need some guidance before I consider taking my shifter apart. My 2002 Ultegra STI brakelever shifter (rear) sometimes misses a shift from the 3rd to 4th cog. I don't think I'm not pushing it enough, as it's just started happening at around 3000 miles, and I use the same effort to shift all the other gears.

It just does nothing, and when I push it again it shifts. It seems like the index mechanism isn't moving far enough to ratchet into the next position?

I was wondering if anyone had experienced this and if there is anything specific I should look for, or should I just remove it and clean it?

It's the that has the single flight deck button on the brake hood (although I don't use a flight deck).

thx, Jack

mine does the same thing. started happening around 12000 miles>>>doesn't happen all the time but is a hastle when you really need it. i always thought it was a chain tension thing, but i'll be looking at this thread for answers as well.
it seems to happen under heavier load (slight incline)

mine does the same thing. started happening around 12000 miles>>>doesn't happen all the time but is a hastle when you really need it. i always thought it was a chain tension thing, but i'll be looking at this thread for answers as well.
it seems to happen under heavier load (slight incline)

Yes, I should have mentioned it happens intermittently, but I can't say that it's consistently happening under load.

I don't think it's anything to do with the chain, because the lever doesn't engage to make the shift, it just moves like there's nothing behind it.

If yours is engaging the cable but not completing the shift, it could be a number of things, but I'd clean the cogs and take a look at them under a magnifying glass to see if they are worn. It could also be a stretched cable, but I would expect that problem to manifest itself across all the gear shifts.

When a cable is only slightly out of adjustment or beginning to stretch, it will demonstrate this by not shifting in 1 or 2 gears, along with the clatter of the chain rubbing against the cogs in only 1 or 2 gears. Easiest thing to do is to loosen the barrel adjuster to tighten the cable. Try it 1/2 a turn a time and see what happens.

And avoid the extreme gear combinations.

55/Rad

When a cable is only slightly out of adjustment or beginning to stretch, it will demonstrate this by not shifting in 1 or 2 gears, along with the clatter of the chain rubbing against the cogs in only 1 or 2 gears. Easiest thing to do is to loosen the barrel adjuster to tighten the cable. Try it 1/2 a turn a time and see what happens.

And avoid the extreme gear combinations.

55/Rad

That sounds like a possibility for rippraph's problem, but my problem is the lever is not engaging, so it's not pulling on the cable.

Had the exact problem, turns out that it just needed a little cleaning and lube. Check out my thread...

http://bikeforums.net/showthread.php?t=31672

Had the exact problem, turns out that it just needed a little cleaning and lube. Check out my thread...

http://bikeforums.net/showthread.php?t=31672

Thanks EagleEye.

What did you use to clean it? I'm inclined to use my Tri-flow spray.

I used Pro Link, which degrease and lube at the same time. I turned my bike upside-down and squirt a little of it in there, worked the shifters a bit get the lube worked in, and wiped off the excess. My shifter had less milage on it compared to yours, so hope you have the same problem I did and not something else. Good luck!

Thanks EagleEye.

What did you use to clean it? I'm inclined to use my Tri-flow spray.

I had a similar problem with my Ultegra brifters. I cleaned them out with a Finish Line Ecotech-2 spray and they work fine now.

Turned it upside down Friday night, used Tri-flow spray while moving all the moving parts of the shifter, road tested Saturday morning, works flawlessly.

I guess the upside down part did the trick, as I had tried spraying it before while on the stand.

Thanks, Y'all