Originally Posted by
R. D.
...Only issue I have with RSX is that every 10 years or so, the rear brifter won't shift anymore, and I need to clean it inside (solidified grease or something, it always happens in cold temps, winter.)...
Shimano brifters are well known for gummed up internals, especially those that sat for long periods of time without use. Bikes that hadn't been used in years are particularly prone to this.
Although Barrett's Bicycle Manual recommends shifter disassembly and soaking in solvent, I found a much easier way.
I used a product called CRC PowerLube in a red can. Solvent plus PTFE (teflon) so it not only gets the gunk out, it lubes the internals.
I'd direct the spray into the shifter, work the shifter in both directions, and repeat. Depending on how gunked up the shifter was, this step could take anywhere from a couple minutes to 10-15 min.
Never failed to free a gummed up brifter, and made them shift more smoothly as well.