Repairing Tiagra shifter lever

trickeyja

On the first hill during this afternoon's bike ride, I tried to shift down onto the small front chainring (I have a double), but the derailleur would not go down properly and was just grinding on the chain. I therefore struggled up the hill using the larger ring, but later managed to shift down. After eventually shifting up again, I found I once again had the same trouble shifting down.

I then began to have trouble shifting up; I pushed the lever hard to the right in an attempt to get the chain on the larger chainring. Unfortunately this has jammed the shifter into the far left position on the dial (as though I am on a larger chainring than the largest on my bike). I can now not shift down at all. The lever to shift down simply moves smoothly backwards and forwards and there is no click at all.

Is there any remedy for this?
Any advice would be kindly appreciated.

redvee

AFAIW the remedy for this is a new shifter

verloren

Have you replaced the rear shift lever at all? It would be relatively unusual to the front shifter to wear out before the rear one did, so it's worth working on the cables first. I'd start by spraying loads of WD40 or GT85 on the front derailler (note: in general WD40 is a questionable thing to use on your bike, but in this case I think it's OK) while manually moving it back and forth to see if something has seized in the mech. If that doesn't work remove the old inner cable (and outer if you're feeling extravegant, the whole thing shouldn't cost more than a fiver) and fit new. It's amazing how an apparently serious problem can be down to a dodgy cable.

If neither of those works it may be the shifter itself that's broken. The bad news there is that Shimano shifters aren't realistically serviceable, so you'll probably have to replace it. How old is it?

desweller

verloren wrote:

It's amazing how an apparently serious problem can be down to a dodgy cable.

They can often fray within the shifter, which is pretty much the last place anyone looks as it's comparatively inaccessible. All but one of the persistent shifting woes I've ever had have have been down to frayed cables (the one broken MTB shifter was understandable - I'd run it through winter with no cover, so it kept getting filled up with rainwater, salt and snow).

As it's jammed up, it sounds like you might have bits of cable floating around in your shifter now, so you might need to get yourself a pair of small long-nosed pliers!

rockmount

redvee wrote:

AFAIW the remedy for this is a new shifter

+1 Tiagras are known for their self destruct tendencies, and are basically irreparable.

trickeyja

Thanks for the advice. I'll see what I can do with a new cable, but if that fails I'll take it to the LBS, and order a new shifter.

I bought the bike in August 2008 and these are the original shifters.

Incidentally this actually happened before a while back, and after struggling around with the levers it seemed to click back into place, but that's not working today! How much will a shifter set me back? Is it possible to get just the left shifter?

verloren

eBay might be a good option - as I said earlier, it's typically the right shifter that goes, so it's not too unusual for people to sell the matching left shifter if they've taken the opportunity to upgrade.

trickeyja

Follow-up here:

http://www.bikeradar.com/forum/viewtopi ... 2#15607052

k2rider

the left hand shifter is more likely to break than the right hand shifter as the spring tension is greater on the front mech than the rear which is why you tend to find an awful lot of r/h shifters on ebay.

Monty Dog

Check the cable first - STIs have a horrible propensity to chew cables - they fray at the head and jam inside the shifter - a frayed cable leads to all sort of shifting problems. If not, try an ample dose of GT85/WD40. Sadly, there's nothing internal that can be repaired if they break.