Noisy shifter

drhaggis

Hi,

I changed the gear cables of my bike (Tiagra 4700) 10 days ago, as well as the housing from the chain stay to the rear derailleur (but not the housings at the handlebar). It's been fine so far but today, about halfway through on a 70 km ride, the rear shifter has started making scratching noises when shifting, as if it weren't properly lubricated. I guess it's either

• Front housings
• Lubrication of new cables is gone (how?)
• Some dirt has made it somewhere in the system
• I mildly screwed up, and the effects are only showing now

Any comments on what is the most likely cause? The shifters are about 18 years old and have about 6000 commuting km on them.

keef66

I'm assuming you mean 18 months old?

Did you lube the new inner & outer sections when you installed them? Did you get the cut ends of the outer perfectly square and clean, and the hole opened up at each end?

My winter bike started squeaking when shifting, and it turned out to be the outer cable from the shifter to the downtube. The individual wire strands were poking out of the cut end so it was no longer square and seated snugly in the DT cable adjuster.

Couple of tips I've learned regarding the loop of outer cable to the rear mech:-

1) Don't make it too short
2) Bend it into it's final shape (use a cable tie if required) before cutting the ends square

I always use sharp cable cutters on the outer, and tidy up the ends with a Dremel disc

drhaggis

keef66 wrote:

I'm assuming you mean 18 months old?

Did you lube the new inner & outer sections when you installed them? Did you get the cut ends of the outer perfectly square and clean, and the hole opened up at each end?

My winter bike started squeaking when shifting, and it turned out to be the outer cable from the shifter to the downtube. The individual wire strands were poking out of the cut end so it was no longer square and seated snugly in the DT cable adjuster.

Couple of tips I've learned regarding the loop of outer cable to the rear mech:-

1) Don't make it too short
2) Bend it into it's final shape (use a cable tie if required) before cutting the ends square

I always use sharp cable cutters on the outer, and tidy up the ends with a Dremel disc

Hah, yes, 18 months old! Thanks for the answer. I used these shimano cables to replace the Jagwire ones that came with the bike.

So the outer cable from the STI to the downtube is the old Jagwire that came with the bike. Replacing that would require removing the current cables, undoing the bar tape and reinstalling the cables, if that's possible with already used & cut cables.

The only piece of new outer cable I used was the one from the chain stay to the rear derailleur, and I measured it to be as long as the old one. I tried to cut it as clean as possible, opened it, and make it as round as possible before inserting the cable. I suspect the length is OK, because it was working fine in the past.

One thing I did not do, however, is lubricating either the new cables or the housing. It was my understanding that shimano cables didn't require it, that they came coated from factory (they were quite slippery as a matter of fact).

I don't know if any of this information is useful.

keef66

Then I'm as baffled as you. Yes, the Shimano stuff comes pre lubed.

Are the shifts accurate in spite of the noise? Did the new inner cable end seat properly in the shifter? Is the outer still seated properly in the cable stop and with it's end caps? Maybe the Shimano inner wire doesn't like the worn Jagwire outer? IIRC it was some second hand Jagwire outer that was squeaking on mine

Since you have the Shimano stuff you could replace the sections of outer between the shifters and the downtube if you're happy re-wrapping the bar tape. (I find it therapeutic and love the excuse for new tape)

This is assuming the inner wires are cleanly cut and the ends tidy to allow you to feed them through a second time. It's tricky if even a single strand is unravelling. Sometimes I've had to sacrifice a used rear wire to make a neatly trimmed front, and then fitted a new rear.