Bicycle Mechanics - Soak gummed up shifter with what?

My right Ultegra shifter with 20k miles is failing, shifting both up and down intermittently. I pulled the rear wheel and can see the der and cable do not move correctly sometimes. I have tried spraying and flushing with everything known to mankind (Carb Cleaner, Brake cleaner, WD-40, ATF, Breakfree, Triflow).

The next move is to pull it and soak it in something. I have read that this can sometimes be effective in cleaning it out.

The question is, what is the most effective grease cutting fluid I could use that will not harm the plastic/ rubber parts?

Thanks for any help. I have tried search and just can not get a clear answer.

The best thing I've used is the white lightning brand clean streak degreaser/cleaner spray.

Leaves no residue at all and dissolves pretty much anything super fast.

Soaking and cleaning will definately fix your problem. The problem is the shifting pawls are stuck or sluggish. I fixed both of my sons shifters by soaking kerosene. How ever I did have the advantage of using an ultrasonic cleaner also. That made the procedure faster is all.

First I'd properly identify the source of the drag. The list of solvents that you've used already contains 4 very effective cleaning and degreasing solvents. So it's likely that you are not working on the correct spot. It could be at the shift lever or in the cable and housing or in the derrailleur. Since you've cleaned the lever overly well already I would suggest you concentrate your focus on the cable and housing and on the actual derrailleur. What you want to do is isolate the cause.

Disconnect the cable from the derrailleur. Push the derrailleur towards the center and let go. It should snap sharply and cleanly back to the outside position. If it's stiff you have your problem. If it's stiff and you've already cleaned the snot out of it with those other things then it's likely that your derrailleur is bent and it's the friction from this damage that is causing the issue.

Moving on to the shift lever. Pull the housing out a little so you can get a grab on the cable. This will isolate the housing and cable from the shifter. While holding some tension on the cable run the shift lever up and down noting the feel. Each click stop going both ways should feel crisp with only a couple of pound of cable tension needed to provide correct cycling. If it feels gummy then there's your trouble spot. Squirt in the brake cleaner and WORK THE CONTROLS to help it clean out the crud better. Nothing will do the job on it's own, you need to work the pivots to encourage the solvent to get into the crud and flush it away. This last bit applies to both the shifter and derrailleur.

If the two ends are good then that leaves just the cable and housing. Over time the cable cuts into the plastic inner liner and can get quite stiff. If you have not changed the cable and housing in a long time then it's very likely that this is the source of your trouble. Buy some new housing and a new slick finish cable and enjoy new found shifting performance.

Thanks rydabent for the input, as you have chosen one thing I was thinking about. I will probably soak it overnight then vibrate it for a couple of hours.

I plan on using a vibrating brass cleaner for cleaning brass after shooting them. It should work fine. I thought about using diesel, but I guess kerosene is better?

Did your relube with grease of just some form of oil?

BCRider,

I have already done all you suggested. The cable and housing have been recently replaced, the rear der moves properly when disconnected, and the cable moves freely when tested by hand. What I found is that the cable released, moved is not consistent when using the shifter.

Ah, fair enough. It was hard to know from the first post if you'd already done that or not.

But it's hard to imagine that there's still any gummed up crud in there after all those other options you mentioned. Any of the big four sovents you've already used should have easily flushed out or at least softened the old grease and made it good again. There may be more at play here than just some grunge buildup.

Yep...Sometimes they just go by-by. Not much luck in fixing these if something internal has broken.

Yep...Sometimes they just go by-by. Not much luck in fixing these if something internal has broken.

Sure, you can't buy spares, but having had a set of STIs apart, I can tell you the internals are fairly sturdy. They're far more likely to fail due to gummed-up grease preventing the pawls from working.

If you have the cajones to attempt this (http://www.bikeforums.net/showthread.php?610670-8spd-Ultegra-STI-shifter-original-style-rebuild-guide&p=10180619), it's worth going to the trouble of removing the circlips that retain the pawls and pulling a bit of rag through the pivot holes in the pawls.

My LBS who has tons of experience says that he has NEVER seen a STI shifter "Worn Out". They get cables broken off in them, and get gummed up according to him. I will proceed with the "Cleansing". If that don't work, I may try the Kimmo suggestion.

Do not soak STI shifters in a petroleum based solvent. You are asking for trouble. Try leaving a plastic toothbrush in solvent for a night. You will see what I mean.

Use a plastic friendly lube like Super Lube Dri Film. That stuff is the best for shifters.

Super-Lube.com