can anyone identify and offer an easy fix for the following.
Shimano STI shifter. Down shifts fine, upshifts for the only the first three lowest gears. I can pull the cable manually and it shifts fine put the shifter itself does not take up the cable slack. Not familiar with these at all but it feels almost like there is a ratching mechanism in there that is missing teeth or are really worn out. But before I start tearing it apart I thought I would check with the ST collective to see if there is an easier fix or I’m missing something obvious.
Make sure the cable hasn’t slipped, or is too lose, on the derailleur.
While downshifting, pull the cable at the derailleur end, and see if it keeps ratcheting after you have got the the smallest cog. If it does then you need to pull more cable through before clamping it in the derailleur.
Taking apart a shimano shifter is a delicate and very nearly impossible task. They are designed with functional obsolescence in mind and not meant to be repaired really. You can’t even get the parts for most of them (unlike Campy and SRAM).Take all the tension off the cable by un doing the cable at the deraileur. With just your hand putting light pressure on the cable, does the shifter still skip? If so, take the cable out of all of the housings and try the self pressure test again. Still not shifting? Then you are hosed. If it shifts fine with either test, your housing length or interior condition would be my first place to suspect the problem is originating. Might just be time to replace housings and cables.
Not sure about a fix for your problem, but I know from experience that these are not easy to take apart and very rarely fixable. Opened mine up few peices fell out and well…thats all she wrote new shifter.
You can’t even get the parts for most of them (unlike Campy and SRAM).Take all the tension off the cable by un doing the cable at the deraileur. With just your hand putting light pressure on the cable, does the shifter still skip? If so, take the cable out of all of the housings and try the self pressure test again. Still not shifting? Then you are hosed.
You’re not filling me with the utmost confidence here
I didn’t pull it off the deraileue but if I manually shift it to the highest gear there is plenty of slack in the cable and it doesn’t shift. That leave only the front cable housing which it feels pretty free, but since I have to pull the cable to get the housing apart I will try it sans housing.
It really does feel like a worn out ratchet, so I’m guessing it’s internal to the shifter and if I can’t get the parts that means I’m hosed. I could probably make one, but probably easier, cheaper and quicker to buy a new shifter.
i dont have any useful advice for you other than i had a similar experience with my ultegra 6700 rear sti levers. figured it was due to sweat and salt getting in there. squirted a ton of wd40 into it, it leaked it out for a whiel afterwards and then it started working again. a few weeks later, happened again. did not use wd40 again, just got caught in a downpour and then it started working again. I would not have been in the downpour had it been working as I woudl have had an easier time getting home, but it did not have a problem again the rest of the year. I am waiting for the X to complain that the bike i sold her wont shift but i will make good if that comes to be.
essentially downshifts to 11 or 12 as case may be and then only 1 or 2 if any upshifts as lever feels like it catches sometimes and sometimes not and then just slips.
essentially downshifts to 11 or 12 as case may be and then only 1 or 2 if any upshifts as lever feels like it catches sometimes and sometimes not and then just slips.
Exactly the problem I have. Started by not catching every once in a while on the upshifts but downshifted fine. Eventually would not shift any further up then 3. It’s my trainer bike so I just let it go because I was to lazy to fix it
Rather then worn it it could just be that some of the teeth are packed full of gunk. Looks like I’ll be taking it apart and finding out as I’ll have to replace it either way.
Shimano shifters aren’t designed to be disassembled. The general advice is to spray the insides with WD40 and work the shifters to get the WD40 into the moving parts. If that doesn’t work you probably need a new shifter.
What everyone else has said - if cleaning doesn’t work, you need a new one. Mine did this, too. I suffered along for about a season - I learned that mine would shift ok if I pulled the lever a bit as if applying the brakes (but before the pads hit the rim) and then shifted. Worked every time, but what a PITA. I hated buying new STI, but once they were installed - ahhh.
I agree with nickag. Something about the grease that they use in the mechanism, but after a while mine stop upshifting.
Hose it down with WD-40 and they’re good to go again. I’ve had two sets of 105 do this (right side only) and just had a Dura-ace (left) do this at a cross race this year. WD-40 has gotten them going again.
We get this complaint fairly often at the shop I work for. We usually squirt the shifter full of degreaser then blow it out with an air hose. If it is just dirty inside this will work, if not it’s broken and will need to be replaced.
WD-40 bath worked like a charm. Sprayed and continued to spray while working the action. Started to catch while pulling back on the brakes slightly and after a few cycles works like new. Thanks all for saving me from myself
never was able to put it back together