Re:
Okay everyone, just to clarify, this is the stuff I use: I purchased it about 10 years ago for $4 in a Radio Shack or hardware store, can't remember. It is mostly alcohol & has enough aerosol pressure to blast the gunk out of the units. It's probably pretty similar to that pressurized air you use to clean out keyboards - the can gets very cold if you use a lot of it. I usually spray enough into the shifter unit that the old grease dissolves, runs out of the unit, and gets wiped away. I restored an old set of the DX push-push units a while back where the left side unit was not ratcheting at all. The first spray inside was enough to get them to start ratcheting immediately. I've never taken any of my STI units apart (too much complexity that I don't want to deal with) - I just spray it into any holes or gaps I can find (usually the cable port), and it makes its way through the unit well enough. Just to clarify, here are my units & their info I've used them on, all with never disassembling & all with the same results:
1990 DX 7-speed Rapidfire push-push shifters/levers (model ST-M071)
1991 XT 7-speed Rapidfire push-push shifters/servowave levers (model ST-M092)
1996 XT 8-speed Rapidfire Plus push-pull shifters/levers (model ST-M739)
1997 XTR 8-speed Rapidfire Plus push-pull shifters/levers (model ST-M950)
1999 XT 9-speed Rapidfire Plus push-pull shifters/levers (model ST-M750)
In my experience the cleaner is strong enough to dissolve all kinds of grease/oil residue, but gentle enough not to damage/discolor any plastic or painted parts. It is strictly a cleaner and not a lube, and dries very quickly, leaving no residue. I also noticed that occasionally when the weather gets real cold, it feels like the shifter can "slip", not catch, and not shift up to the next gear - that is the remaining grease inside stiffening up and not allowing the pawls to retract back fully. A little spray inside remedies this and usually lasts for at least a year or two until I have to use it again.
Okay everyone, just to clarify, this is the stuff I use: I purchased it about 10 years ago for $4 in a Radio Shack or hardware store, can't remember. It is mostly alcohol & has enough aerosol pressure to blast the gunk out of the units. It's probably pretty similar to that pressurized air you use to clean out keyboards - the can gets very cold if you use a lot of it. I usually spray enough into the shifter unit that the old grease dissolves, runs out of the unit, and gets wiped away. I restored an old set of the DX push-push units a while back where the left side unit was not ratcheting at all. The first spray inside was enough to get them to start ratcheting immediately. I've never taken any of my STI units apart (too much complexity that I don't want to deal with) - I just spray it into any holes or gaps I can find (usually the cable port), and it makes its way through the unit well enough. Just to clarify, here are my units & their info I've used them on, all with never disassembling & all with the same results:
1990 DX 7-speed Rapidfire push-push shifters/levers (model ST-M071)
1991 XT 7-speed Rapidfire push-push shifters/servowave levers (model ST-M092)
1996 XT 8-speed Rapidfire Plus push-pull shifters/levers (model ST-M739)
1997 XTR 8-speed Rapidfire Plus push-pull shifters/levers (model ST-M950)
1999 XT 9-speed Rapidfire Plus push-pull shifters/levers (model ST-M750)
In my experience the cleaner is strong enough to dissolve all kinds of grease/oil residue, but gentle enough not to damage/discolor any plastic or painted parts. It is strictly a cleaner and not a lube, and dries very quickly, leaving no residue. I also noticed that occasionally when the weather gets real cold, it feels like the shifter can "slip", not catch, and not shift up to the next gear - that is the remaining grease inside stiffening up and not allowing the pawls to retract back fully. A little spray inside remedies this and usually lasts for at least a year or two until I have to use it again.
