Sunday, February 27, 2011

Shimano Ultegra Shifter Jamming After Broken Cable

Last year the cable broke inside my Shimano Ultegra 10-speed rear shifter. The cable was just 6 months old with less than 3000 miles. I rode home and found that I could not remove the nipple end fragment of cable. I could shift back about 5 gears by creating some torque on the shifter drum with the sharp end of a small screwdriver, but I could not get all the way to the "small cog" end of the shifting range. I finally removed the unit from the handlebars in preparation for taking it apart. I made one more try, and found that the loose cable end had apparently moved, no longer jamming the mechanism, and I could rotate the drum back to home position and remove the nipple and cable fragment. The nipple was still in its socket.

Well it just happened again, this time after 13 months and about 3000 miles. This time the unit was totally jammed. I removed it from the handlebars and rapped it a bunch while holding it in various positions. It finally started to "shift" but this time the cable fragment was no longer seated in its socket and was badly jammed way underneath. It took about an hour of shaking, shifting and probing with tweezers and wires to get it out.

Unlike older shifters which had a drilled hole where the cable sits in its socket, this 10-speed shifter has a notch. This makes it much easier for the broken end to fall out and jam the mechanism. Thanks, Shimano.

Both cables were genuine Shimano. Perhaps some other brand will last longer.

(In the process, I tried to remove the combined main shift lever and outer shell to get at the loose end. I got as far as a small Phillips head screw underneath the lever with a locking plate. Even with the locking plate disabled I was not able to loosen the screw.)

Lessons learned:
  • Replace the rear shift cable every 2000 miles and the front every 4000.
  • If the cable breaks, try to resist repeated clicking of the shift lever, which just rotates the loose end to the bottom where it will fall out.
  • If the cable breaks, try to get the loose piece (cable end and nipple) out of the shift lever immediately. Riding the bike is likely to jar it loose.
  • If the shifter is jammed after a broken cable, try inverting the bike and then shaking it or tapping the shifter with something like a screwdriver handle.

9 comments:

Nigel said...

Thanks for this Mark - I have lost the end inside my 10 speed shifter and you've given me some ideas. I'll report back how I got on.

Anonymous said...

Did you ever find a way to extract the broken cable head that is loose inside your shifter? I have a similar prob with a 7800 shifter that my shop has unsuccessfully attempted to extract. Shimano reps told them do NOT attempt to disassemble the shifter. If anyone has found a solution, I'd be happy to know it.

Mark said...

I removed part of the housings that enclose the mechanism (I remember removing a small phillips screw and then a nut about 1 cm in diameter with a locking plate) and then, as I said above, spent about an hour of shaking, shifting and probing with tweezers and wires to get the piece out. There's an annoying spring that is a bit difficult to get back in place, but you CAN do it. Take photos with your digital camera as you go!

Mark said...

Maybe this will help:

http://www.norvil.net/pedal/service/shimanosti/duraace9sti/strip.php

The Shimano reps just want you to buy something new. The worst that can happen if you disassemble it is that you throw it into the junk pile in a bunch of pieces rather than as a complete unit.

Anonymous said...

The end of the broken cable was vitually out of sight at the bottom of the shifter on my Ultega shifters. After much fiddling with shifter levers and pulling on the frayed end of the cable with a VERY FINE SET OF TWEEZERS, which were just able to reach ths cable end I eventually managed to free the cable end and the Cone shaped housing it sits in.

Mark said...

Note that this thread is about "older style" Ultegra shifters, not the newer ones with Aero cables under the bar wrap.

Mark said...

More here:
http://ccorlew.blogspot.com/2011/06/more-on-ultegra-6700-and-6600-shifter.html

And here:
http://ccorlew.blogspot.com/p/shimano-ultegra-shifter-cable-frayed.html

Mike Johnson said...

I just had to do this, it wasn't that hard and there was no drilling required, contrary to some of the other posts linked.

These are the instructions that I followed and I had it out in a few minutes.
- Remove shifter from bike handlebar, you’ll have to disconnect the brake cable and slide it out of the housing and undo it from the brake lever.
- Remove the dust covers from the shifter mechanism.
o Remove the screw from the chrome end cap, the part that says Ultegra on it and pop off the end cap.
o (Somewhat optional step though you can see better with these removed) Remove the screw that secures the two dust covers on either side at the back of the shifter mechanism (just in front of the brake cable connector) and remove those two dust covers.
o Remove the screw from the main dust cover on top of the shifter and bend the locking tabs back from the 8mm nut on the front of the shifter(just above the lever)that secures the dust cover in place, enough to get a socket on it. Loosen the nut and take it and retention plate behind it off.
o Then use a flat blade screwdriver and gently pry loose the main dust cover exposing the shifter barrel and the gearing.

- Use a small flat head screw driver and push the gear cog towards what would be the center of the handlebar if the shifter were still mounted to the bike, as you work the small shift lever. This should work the barrel around until you can see the end of the broken cable, you should be able to repeat the click and push on the gears until it rotates clear and you can remove the broken end. You have to push on the gear wheel because normally the spring in the derailleur would provide the return pressure to pull the barrel back around, with the cable broken off you have to manually provide this return pressure so the barrel rotates.

- (If you are adept enough and have a very small flathead screw driver it might be possible to reach in through the access slot and rotate the barrel mechanism without removing all the dust covers but the cable may snag on the dust cover and hang up the rotation of the barrel. Also you can see what you are doing way better with the dust covers removed.)
- Put it all back together in the reverse order and remount it to the handlebar, insert your new cables and adjust as needed and you are off and flying.

David Wilkins said...

Thanks for that Mike. The first time this happened to me I gave the unit to a friend to have a go at. Well, he got it apart anyway...
Next time, I followed your instructions, and after a few minutes, Bingo! The cable end practically just fell out.
I would say though that before performing the 'somewhat optional' step of removing the two dust covers either side of the back of the shifter mechanism, I wasn't getting on too well and was about to give up. After removing them, the shifter shifted all the way round - the full nine clicks - and I was easily able to pick out the cable end with fine pliers.
Once again, thanks!