10:25 PM

Old Sti Shifters

A lot of higher end 90s bikes have the first generation of Shimano Integrated Shifters (STI shifters).  The problem with these is that they come greased and over time the grease catches dirt and becomes sludge.  The sludge acts on the ratcheting system, particularly the release pin to return to higher gears.  This renders them unable to shift properly if shift at all. 

Not to worry though, most of them can be fixed with a little bit of degreaser.  Just dip it in a solution of diluted Simple Green and leave it there over night.
Picture 4313
This works 80% of the time.  If it doesn’t, before trashing the shifter you can try ultra sonic baths if you have access to one.  Lastly you can always pry the covers open and figure out what’s wrong but that’s a rather tough job.