philburden

I've recently picked up a 2007 Giant TCR C3 which is fitted with the Ultegra 6600 groupset. I bought it knowing that the shifters where not working well, but the previous owner had not riden it often, in fact not at all in the past3 years or so. I figured a simple flush and lub of the shifters would get them working again. The left was not working at all and the right was half working. It didn't always catch when shifting back down the cassette. I had to move the trigger slowly until I felt it catch, to fast and it wouldn't catch. I tried flushing them and this worked fine for the left shifter but in cleaning and flushing the right I found that it now catches nicely on every push of the trigger but does not click (aka complete the shift). I noticed that the shifter will only shift if I pull of the gear cable still attached. Has anyone seen this happen before? Since the rear derailleur kind of keeps it under tension, it will "work" but it would be nice to have it running perfectly. Thank you for your help!

deacon mark

This sounds like a cable problem not a shifter problem but I am not sure I follow you completely. Put new cables and housing on the bike first and foremost then see what happens. Be careful and do a good job with smooth bends and get die drawn cable and good housing like jagwire or shimano.

popeye

What deacon said. When I had cables they got replaced once a year.

philburden

This is a difficult issue to explain. I will try to better express the issue. I have taken the shifter off the bars with the shifter cable still in place in the shifter (not attached to the RD). If the cable is just dangling, the shifter will shift up (moving the whole lever) but won't shift down (moving the trigger). It feels like the trigger wants to actuate, as there is resistance and things in the shifter are moving, but it does not actually click and release the pawl. If I then pull on the end of the cable, applying tension, it will complete the shift. As in there is the sound of a click.

Now to your suggestion that this might be cable related. I did remove the cable from the shifter altogether and tried shifting. Again, the shifter will shift up but not down. i.e. I shifted all the way up and can no longer shift all the way down to insert the cable (to apply tension and shift down). And so I am here, stuck with a shifer that I can't insert a cable into.

Hope this helps, you or anyone trying to help!

deacon mark

The shifter does in fact have to have some tension on the cable to click down. If you insert the cable correctly in the shifter then holding tension on the cable without it actually being attached to the derailleur it should sift both ways up and down. It will not simply click down into a higher gear if the cable is just dangling loose. In the event that this is really a shifter problem and they are bad this is easy. Just buy a set of 105 10 speed shifters and be done. They are not expensive and will work with what you already have. Possibly find 6600 that is lightly used of 5700 6700 series.

philburden

Thanks! This is odd as I am able to shift up and down with the left shifter without a cable. Anyhow, as I said in the original post, the shifter works alright when connected to a derailleur so im assuming it will be ok. In the even I purchase a new shifter, where do you recommend purchasing one? I've checked ebay and they aren't THAT cheap.

masi61

When you removed the cable from the shifter did you inspect the end of the cable for small breaks near the barrel? Is it possible that one or two tiny shards of broken cable are stuck in the shifter mechanism? The symptoms you are describing match what happened to me on 2 different occasions with Dura Ace 7700 series and 7800 series shifters. With the 7700 we caught it before the cable gave way completely. With the 7800 I wasn’t so lucky. I was on a ride and shifted at the base of a hill and heard and felt a cracking sound inside the shift lever. I had no shifting on my front shifter for the ride home and when I set out to remove the cable, almost all the strands were severed, it helped having lighted magnifying glasses and a skinny pick that I could remove the broken strands one at a time until the shifter barrel could finally be advanced enough for me to poke the orphaned cable barrel back out from the recess in the shifter barrel. A new Jagwire burnished (die drawn) stainless cable installed and set up the 7800 front derailleur and now my front shifting is spot on with easy clicks for both up and down shifts. Thinking back on it, the shifter had been intermittently “missing” for quite some time. It would take 3 or 4 sweeps on the down shift paddle before it would catch but the effort felt hard/crunchy. Next time I’ll know.

I hope this helps. From your description it sure sounds like a cable that is fracturing. Please check the cable you removed for tiny breaks, and whatever you do, don’t reuse the old cable.

masi61

philburden - I was just following up to see if you determined the source of the shifting issues you were having. Was there any possibility that my illustration above of a cable with broken strands might apply to your malfunction?

philburden

Sorry for the late response. The cable seemed to be in good condition and was not the cause of the problem. That being said I have figured out what the problem is and I will soon post the actual issue and my tentative solution!

RiceAWay

A lot of the Shimano levers did this. My suspicion was that the grease they used hardened in-between the layers of parts of the shifting mechanism. I have NEVER gotten them to work correctly by flushing them out with penetrating oil. I did get them back into working shape by taking the entire mechanism apart, cleaning each separate part and reassembling using a high quality grease. This is painful and time consuming so if you could buy newer levers that would be a good idea.

curbtender

The most common issue is the pins on the pawls gum up and don't spring back proper. Flushing doesn't always get to these. If you can partially disassemble and rock them back and forth with something, I use an ice pick, they will usually free up.

philburden

Turns out the shifters does NOT shift very well when attached to the RD. I can't get cable tension high enough to get the shifter to release the cable.

philburden

*(POSSIBLE) SOLUTION*



So after lots of fiddling around with this shifter, I already knew flushing them would not be very helpful as I had already done it. So I attempted to at least take it apart enough to observe how the mechanism works. I've added a sketch of the issue I discovered and how I fixed it. All in all, the shift lever was not lifting the pawl high enough to clear the gear tooth. And yes, I did make sure to clean it, it was spotless so old grease was not the reason for this. It just seems like the lever did not actuate the lifting mechanisms high enough so I had to take it into my own hands. I decided to use a thin washer, cut and bent into shape and JB Weld it to the piece. I've added multiple layers of JB Weld to improve durability. It's not like it's there is a high torque applied to this piece so I expect it to last. Only time will tell. I'll keep this post up to date if it fails.