STI shift levers won't shift down

donb said:

Both of my Ultegra/600 shift levers (circa 1998, 8 speed) frequently won't
shift down, particularly when it's cold outside. Both small inside levers
move through their full range, but it's as if there isn't enough friction
and nothing happens. Is there anything that can be done to increase the
friction or otherwise fix the problem?

Thanks in advance.

Just to exclude most obvious problems, check cables and housings, in
particular under the bottom bracket. Then maybe try to flush the levers
with WD40.

Francesco

"donb" <[email hidden]> wrote in message
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Quoted message said:

Both of my Ultegra/600 shift levers (circa 1998, 8 speed) frequently won't
shift down, particularly when it's cold outside. Both small inside levers
move through their full range, but it's as if there isn't enough friction
and nothing happens. Is there anything that can be done to increase the
friction or otherwise fix the problem?

Thanks in advance.

Move south OR flush out the cable housings, front and rear (or replace) with
some WD-40. The Shimano cable lube that comes with the levers when they were
new slowly turns into glue. Replace the cable at the same time unless it is
reasonable new. Ten bucks and you should be good to go.
Bill Brannon

I'd also degrease the brifters - the glue/lube that shimano uses is not
limited to the cables. As previously noted, WD40 works reasonably
well, although when my old ultegras started doing this, I ended up
resorting to a bath in citrus degreaser, a nice rinse followed by
thorough drying, then dousing the mechanisms with mineral oil. I had
no problems with the levers for several thousand miles after that -
until one near-miss induced crash too many toasted my rear brifter.
Just be sure to remove the hoods if you do the bath - citrus degreaser
and shimano hoods don't always get along.