Originally Posted by
big john
My 6600 bike has done that on both shifters. I don't ride it very often and I have tried WD-40 but it gets gummy in there after the bike sits in cooler weather. The last time I used silicone spray lube and the shifters worked great after that. Turn the bike upside down and spray into the shifter at the base of the lever.
Yup. I don't like WD 40 for anything but water displacement (WD) and temporary protection, or as a penetrating lube if nothing else is available. I don't like to put a residue anywhere un-cleanable. In my opinion, Silicone or PTFE or maybe even graphite would the right approach after using
rjones28 suggestion of a solvent.