I normally commute on my CX bike, which uses drop bars and Tiagra STI brake / shifter units. Last December the gear shifter on the left hand unit kind of imploded - it just jammed and wouldn't move. It was replaced under warranty in January (bloody christmas break cost me three week's commuting!), and has been fine since then, even after I broke the window in a crash back in April. Now, however it's started playing up again.
It's reluctant to move up from inner to outer ring (I run a 34.50 double). It will move eventually, but then won't drop back down again. If I release the cable though, it works fine - it only seems to have problem when it's under load, remove the load and it pops up and down with no problems at all
any ideas, anyone?
PS the good thing about having more than one bike is that there's always a spare to fall back on when your main bike is "hors combat" 
