Robert Haston said:After sitting idle for months, the left (front derailleur) shifter on my 98
vintage MTB will only advance one click from low to medium, and the problem
cannot be adjusted out.
I'm not familiar with thumb shifters, but it seems there is some internal
ratchet that only goes up one click and won't catch the second one. It
looks like cracking the case to figure out what the problem is might result
in tiny parts springing about the garage; so I thought I would ask around
first.
Sure, go ahead, flip it over and remove the cover . You
should see a crack where on of the ratchets attaches. It
will be askew and unable to engage. If that's the case, seek
a replacement lever , either a top shifter for $10 or an
original Shimano part.
If all ratchets engage properly, flush with some kind of
aerosol -- WD40, TriFlow, SuperLube, LPS3,whatcha got?-- to
clear out accumulated crud.
I've found the road levers are more likely to be crusty and
MTB models more often cracked but both modes are found in
both STi designs.
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971
