Bicycle Mechanics - Ultegra brifter Repairable

I am going to assume the worst, but can ultegra ST-6400 brifters be rebuilt? Right side has almost no spring return on upshifts. Downshifts the lever will return, but only if I use a more violent release on it. Tried flushing with wd40, lubing etc, but no improvement.

Any ideas?

I use PB blaster to clean mine out, soak them in that for a day. Let them dry for a day. Then literally PACK them with light web grease, White lightning rock and roll or pedros syn lube while shifting to get it in all the little places. However this only worked when my shifters got "gummy" on the down shifts on my right levers.
It sounds like if it isn't returning at all, it might be a broken spring, since what you did should have loosened up the old grease enough to at least make some return. There is very little return though since the derailleur cable should pull it back on the upshifts anyway. You could just thread a spare shifter cable in there and pull lightly like a derailleur does and see if you can make it through all your gears.

The only way I know of is to get another and use parts from both to build one up. shimano does not sell repair parts for these shifters.

http://www.bikeforums.net/showthread.php/610670-8spd-Ultegra-STI-shifter-%28original-style%29-rebuild-guide?p=10180619#post10180619

The problem with WD40 is it dries and leaves behind a residue that attracts dust and gunk. It could be just gooed up inside, especially if the return is just slow.

The problem with WD40 is it dries and leaves behind a residue that attracts dust and gunk. It could be just gooed up inside, especially if the return is just slow.

The primary ingrediant in WD40 is an extremely light weight mineral oil. In fact its so lightweight that it can be used as a degreaser.

Sounds like you have an overactive imagination. The propellent evaporates and leaves behind that light mineral oil which neither dries up nor has a tendency to gum things up.

WD40 is an excellent rust inhibiter and its only downside is that its so lightweight that its only suitable for use as a lubricant in applications where frequent application is anticipated and acceptable.

Taking those brifters apart is a pain in the butt, so leave that until you've tried cleaning it some more first. And if you do end up taking it apart, be really careful that a spring doesn't jump out and run away, I spend almost an entire day not able to find one in my shop.

Time for some more soaking I think.

The primary ingrediant in WD40 is an extremely light weight mineral oil. In fact its so lightweight that it can be used as a degreaser.

Sounds like you have an overactive imagination. The propellent evaporates and leaves behind that light mineral oil which neither dries up nor has a tendency to gum things up.

WD40 is an excellent rust inhibiter and its only downside is that its so lightweight that its only suitable for use as a lubricant in applications where frequent application is anticipated and acceptable.

The primary ingredient in wd40 is deodorized kerosene (They use a very narrow cut, but functionally, it's still kerosene.). It's about 75% kerosene, 20% light and medium weight oil, with the balance being wetting agents and corrosion inhibitors. It's the wrong tool for any job, because there are better ones for any task. But you're right that it doesn't have some strange residue; it's just oil. It doesn't have any of the additives that you'd expect to find in modern lubricating oil, so it's not very useful as a lubricant. (But it's pretty compatible with real lubricants, at least once the kerosene has evaporated.)

Oil does, of course, attract grime, but that's not unique to wd-40

My STI shifter was DOA or I thought. I sprayed WD-40 as instructed and nothing. Being frustrated I sprayed an entire can and caught it as it drained in a small plastic container so I could leave let STI handle soak. I was quite surprised by the amount of crap that poured out with some rinsing sprays of fresh WD-40. The resulting oil was almost opaque with particulate. After a few articulations of the shifters while keeping the cable under tension I managed to get the shifter to run through the clicks and return.

I haven't remounted them to test them under normal use yet, but I do not see why they wont work now as they shift quite easily.

Sounds like you have an overactive imagination. The propellent (sic) evaporates and leaves behind that light mineral oil which neither dries up nor has a tendency to gum things up.



Well, I have been accused of having an overactive imagination. :D


WD-40 will leave a gummy residue that will make intricate machinery work poorly. ;)

WD 40 has restored many many STI shifters to good performance. It saved my D-A shifters 10 uears ago. Use lots.

Oily residue that attracts dust is not an issue in these mechanisms - what stops them working is a lube that gets gummy by itself. WD40 doesn't go gummy.

For a start, not a lot of dust is going to make its way right inside the mechanism... then there's the fact that the chances of any dust making its way into the little pawl pivots that are crucial to STI's operation is minuscule.

So you can use WD40 to flush STIs without any fear, but it's pretty useless for anything beyond getting them working again. IMO a heavy oil is the best substitute for grease (which can only be applied by disassembling). Don't worry about the oil collecting gunk; just drain as much excess as possible.

If by some chance the oil does manage to collect enough crud to seize the shifter, just get the WD40 out again.

I've had better luck with silicone spray instead of WD-40 on Rapid Fire and STI shifters. It still frees them up but doesn't attract as much dirt or get gummy as fast as WD. Also, the lubricant remains longer.

Finish Line makes a new spray degreaser (it's in a big yellow can) that seems to free these things up too. It evaporates fast so there is little leftover residue.

Back in the mid 90's at a Shimano dealer's meeting, the question was brought up about disassembling these shifters for rebuild or repair and their answer was "Don't do it". :rolleyes: