rfmarotti

Recently my ultegra 9 speed shifter has routinely started to miss upshifts. I will push the lever the entire length of the throw and nothing will happen.

I did some research and tried as many suggestions as possible:

making sure I was not slightly depressing brake or catching downshift lever: I did not appear to be doing either of those things

lubrication: made no difference.

remove small rubber ring around downshift lever that might be catching on upshift lever: removed and made no difference.

The only way I can reliably up shift is if i my fingers are on the very bottom edge of the lever. Shifting from that position appears to work consistently every time. However, that makes for an awkward hand stretch off the hoods or tops.

Any idea what the problem could be?

dsaul

When was the last time you replaced the shifter cable? Cables sometimes fray inside the shifter and cause erratic shifting. Its best to catch it before the cable breaks and jams the shifter.

Raiden

And while you have the cable out of the shifter (per the above post) flush the ratcheting mechanism with a silicone based aerosol spray, from every direction you can possibly point the tube, and actuate the levers to let it work in.

Edit: do not use wd-40

headasunder

dsaul suggestion is a good one, and I suspect you will have to flush the shifter out with copious amounts of wd40 and re-lube... that usually does the trick as long as nothing inside the shifter is broken.

digger

I know how this is going to sound.....

I had a set of 2000 105 STI shifters where the right/rear shifter, after about 4 years of use, had difficulty shifting when it was cold outside. Exactly the same problem you describe.

I now have a 2010 105 rear shifter that is doing the same thing on the 3rd cog up; I have to push the thing all the way to the left for it to shift. Works fine on all the other cogs, works fine on the bike stand and works fine when it's warm outside, but in the cold, that shifting issue occurs.

???

rfmarotti

Was fully re-strung 2 months ago. Can cable stretch account for this behavior? I will also lube as suggested.

rfmarotti

Define cold? I commute on this particular bike and it may be as "cold" as mid-50s in the mornings, but the problem occurs on the (70-85 degree) ride home too.

Given that you're from NS I expect you and I have very different definitions of cold.

digger

On Saturday it started off at 5 Celsius (40) and went up to 8 Celsius (46). I can't say at what temperature it stops. But it did seem to do it a little less as the ride wore on.

By the time it reaches 75 here, the issue will have gone...until November.

digger

I don't recommend lubing inside the cable housing, if that is your intention. I have found that it attracts dirt and gums it up. I do shoot some Silicone lube in my housing though.

rfmarotti

Right, meant just shooting lube into the shifter, not the cable housing.

Squeezebox

I'll guess yes.

rfmarotti

I think you're "dumb n00b"-ing me w that comment @Squeezebox but I couldn't find anything that tied the two things together. I will try to tighten up the cable tomorrow and see if it resolves then come back and publicly eat crow if warranted.

Kimmo 

IME the 9s shifters have some extra failure modes over the relatively bulletproof 8s STIs, which pretty much only suffer from sticky grease... they also suffer from wear, and/or tired springs.

This could well be one of those, and as such not amenable to the WD40 flush. My right 105 9s STI may have the same issue, depending on what you mean by upshift (up to a bigger cog, or up to a higher gear?)...

If I shift normally, it doesn't reliably pull the cable, but releases it fine. It drove me nuts for a while, but I found the trick: when pushing the big lever, the way to make sure it engages is to also put a little pressure on the small lever - easy, and works 100% - at least in my case. YMMV.

rfmarotti

Per @Squeezebox 's suggestion I checked cable stretch and everything looked fine. So I started looking around the used market to find a replacement. Last night I was bored so I thought I would try flushing it again. I felt like I went a little over the top spraying way more WD-40 than last time, but this time I noticed some of the WD-40 dripping out clearly had some black gunk in it. So I kept going at it until no more black gunk was running out with the excess WD-40. Let it dry, then relubed with silicone spray. It now works flawlessly.

tl;dr: use a lot of WD-40 when trying to flush mystery problems out of Shimano STI levers. No, more than that. Keep going. There you go.