Friday, December 14, 2007

Q&A: Fixing Shimano STI shift levers

Q: Jim,
After making a quick web search concerning repairing RSX brake/shifters, I came across your name. I have an immediate need, and I was hoping you could help. I have an old Raleigh touring bike with RSX brake/shifters. It's been in storage for awhile, but then I took it out and have been riding it frequently (in the cold and rain sometimes). Shifting became intermittent, so I tried spraying silicon lube right into the crannies of the shifter, and had the cables replaced. I think the cables may have helped one problem, but I may have created another.

I removed the screw on the front of the unit, the only one you can see with the hood on. When I pulled the cap away from the housing, I heard a 'tik!'. Damn it - the torsion spring relieved itself, and I knew it would not be fun to reinstall. I did manage to reinstall it with the spring in the right holes, but the shifter continues to have intermittent function. I suspect the spring had a preload, and I did not wind it or reinstall it right. Does this front spring have a preload? How do I reinstall it right?

Last night, when it was around 39 deg F outside, my shifter did not engage at all. Earlier, when it was warmer, it worked intermittently (I'd sometimes have to flip it a few times before the upshift caught). This suggests a lube issue, but how the heck do I lube this thing?

Any advice would be greatly appreciated.

A: Hi Matt,
Unfortunately, Shimano STI levers aren't designed to be serviced by the user (apart from very basic service unrelated to the shifting mechanism), which is why you won't find any information on this on their website. You're not supposed to try to take them apart. Instead, if you have a problem, you take your bike to a local shop, have them take a look, and if it's a defect, they ship the lever to Shimano and see if the company agrees it's a defect and if it is, and you're within the warranty timeframe, you get a new, working lever from Shimano.

It sounds like you unscrewed the main piece holding your lever's shifter together so getting it covered under warranty is out of the question now, though it was probably too old anyway. I'm not certain if that spring has a preload or if you just unscrewed the bolt when the spring was under load and it released. The fact that you were able to put it back together is a good sign. And, it sounds like it works just like it did before you took it apart. You might try again flushing the shifting part with a penetrating lube like WD-40, something that you can spray into any little gaps into the mechanism you can find. Do this inside where it's warm so the lube is thin and any gunk inside the lever is, too. I've heard that a good "lube rinse" will sometimes free a sticky, non functioning RSX STI lever.
If you're lucky, that might work and get you going. If not, you might instead search on for used RSX shifters (or any Shimano STI levers compatible with your bike) and see if you can't find a right one or a pair for a decent price and then just use your old one for spare parts as needed in the future.

If you want to read about how other people have managed to fix their Shimano
STI levers, here's a link that might help you out: This page is old and some of the links on it no longer work, but it's at least a start and maybe it'll help you figure out your lever and get it working again. If you search for the phrase "STI repair" you'll find a few other links with some interesting comments, too.

Good luck and sorry I can't provide specific repair instructions,


Anonymous said...

I have a circa 1998 Trek XO1 fitted with Shimano STI RSX shift levers and with an 8 speed rear cassette and 2 cog front deraileur. I am experiencing intermittent shifting capability on both left and right small levers. I have read on the internet that the probable solution to this problem is a thorough clean with a degreaser and then lubrication with a synthetic light lube. However, I would like to take off the front cover and am unsure how this is achieved without ending up with a handful of springs and washers which I then cannot refit. Can you explain how this is done?
Many thanks,


Jim Langley said...

Hi Paul, Why do you want to take the lever apart? That's probably not going to make it shift any better and may render it useless unless you can put it back together again. I would recommend just spraying some lube in there and trying to free the mechanism up. But first I would check the cables to make sure that's not the problem since sticky cables are very common.


Anonymous said...

In case this helps others tearing their hair out over RSX STI levers: I naively removed the front cover on my 1997 Shimano RSX STI shift lever -- the big allen bolt on front practically invites this -- then heard the "ping of horror" of the torsion spring unloading and popping out. Shimano and bike shops of course offer only the trivial (costly, and wasteful) solution: buy a new one.

But after an hour of frustrating experimentation, I did manage to replace the cover and spring (with proper tension) without special tools, by using the spring cover itself as a "wrench" to rewind the spring.

Here's how: Insert the thin washer precisely into the circular groove in the cover where the spring sits, with one bent end of the spring inserted into the small slot at top of the inside fo the cover (12 o clock). Compress the spring with your thumb to make sure it is flat and level when compressed, and the washer stays in place surrounding the spring. Then find the hole in the inside of the lever cover (at 6 o'clock)where the other end of the spring inserts.

Next, with the lever in normal vertical position, very gently align the cover and press it into the lever until the free end of the spring can be inserted in the hole. At this point, the cover will be rotated 45 degrees clockwise from its fully installed position. Now, using thumb and 2 fingers, firmly push the cover in, keeping the spring engaged at both ends, while very firmly rotating it about 45 degrees counter-clockwise, until you can line up the square center hole then insert the allen bolt.

It seems to work as it did before assembly.

For a more elegant method of rewinding and holding the spring (during reassembly of a Shimano Ultegra shifter) bloggers at
suggest using a sewing "loop turner" with a homemade clamp, or a "dental hook." I don't know whether such tools would work with the larger diameter RSX spring.

Chevy Chase, MD

Jim Langley said...

Thanks, Tom!

Bill said...

Yes, I just got through a successful fix after I got too far down the road in disassembling. A better way to fix the stuck shifter if what I did to the left shifter. I first sprayed carb cleaner into the mechanism, followed by a wd-40 type product. After several hours I tested the unit for a minute at intervals during the day. After several attempts it worked perfectly as if it never had an issue. Way easier that disassembly and reassembly. I was very lucky to get the right shifter all back together and working.

Jim Langley said...

Appreciate you sharing this tip, Bill!

Danno B. said...

Finally found a good use for that can of carb cleaner that I bought to get an old weed whacker going again (which it never did). The left-hand shifter (Shimano) controlling the front deraileur was only moving between 2 of the 3 gears. Removed lower dust cover and sprayed carb cleaner in & saturated ratchet mechanism. Worked that in with several clicks, then followed it up with a good dousing of WD-40. Worked that in for a few minutes, wiped up excess and left it to dry over night. After that, the shifter was clicking through all 3 gears perfectly.

Jim Langley said...

Thanks for the tip, Danno!

Anonymous said...

Thanks for the carb cleaner tip. It provided a use for the old can of carb cleaner I never threw out, and cured the "no shift" problem I was having with both small STI levers (especially in cold weather).

Back 2 Bikes said...

In the interests of recycling old bikes for the community, I have had good success with a partial and careful disassembly of the shifters. This allows enough access to the small moving parts so that they can be soaked in solvent, cleaned, and then regreased. Most times the shifters are just gummed up and not worn out or broken.

I'm now offering brifter servicing in Australia, see

I'll make a video soon about the process for those of you who want to try it yourselves, or who can't be bothered to send me shifters. I'll put the video on that brifter page.



Jim Langley said...

Thanks, Mike!

Dan said...

So happy to have come across this article. II was able to restore my RSX brifter by reloading the tension spring on the front via Tom's directions.

Jim Langley said...

Glad to hear that the tips here on my blog helped you fix your shifter, Dan! Thanks for letting me know!

Jim Langley

Anonymous said...

I fixed old Shimano STX-RC shifters last fall without problems. Just needed to be careful, especially with the spring at the bottom when putting things together after dismantling and lubing (this can be difficult, if one is not used to putting things apart and rebuilding them). I cleaned every part and applied thin layer of higher quality Finish Line grease that I know to work also in cold weather. The shifters were not engaging at all, but now they work like a dream. I also noticed that at least with these recycled shifters there was no noticeable wear in any part so most probably people are throwing away a lot of shifters that are just in need of cleaning and some new grease.

Jim Langley said...

Thanks for the tips, anonymous. FYI mountain bike shifters are easier to fix than the STI road levers this thread is talking about. But good job fixing yours up!


John S. Allen said...

Jim McVey fixes 7- and 8-speed STI road shifters, except for Tiagra and Sora. He doesn't work on 9-speed shifters, as they are too likely to break.

John S. Allen said...

Correction: McVey will work on Tiagra levers but not Sora levers.

Jim Langley said...

Thanks so much for the link to the articles on Sheldon's website, John, and for telling us about John McVey's Shimano STI lever-repair service. That's a wonderful thing that someone is fixing these levers.

Appreciate the tips and I hope you're doing great, John!

Best wishes,

Anonymous said...

This posting is awesome. I thought my shimano shifters were toast (little tiny springs unable to properly "move" the claws). In any case carb cleaner and WD40 rocked it out. They are good as new now. Motivated me to lube the cables as well. THANKS SO MUCH for this posting.