Originally Posted by jacksbike

Hello Everyone,
I am a long time volunteer at a local non-profit that repairs and gives away bikes. We receive quite a few 90's era ATB's with Shimano Rapidfire shifters that are gummed up and do not operate. I am looking for suggestions of what solution(s) to soak the shifters in (off the bike) that will dissolve the hardened beeswax -like old Shimano grease. So far I have been pretty successful soaking them for about 2 days in gasoline but I am not crazy about the residue left (or flammability). I have heard of using mineral spirits, acetone, brake fluid, etc... I would like to use something safe and if possible non harsh chemicals, I am open to any and all suggestions to solve this problem ! Thanks in advance.