Gear levers adjustment? Shimano 105s

AliR

Hi,
I've got Shimano 105s on my road bike and a triple chainset, and when I change down from the big gear at the front (ie the one operated by the left lever) the chain jumps right from the big gear to the little one so I have to use the lever again to move to the middle gear - which doesn't make for a smooth transition going up hiils.

I am wondering if anyone has come across this problem. Is it just an adjustment?, someone suggested my front left lever was for a double chain set which was why the chain was jumping too far.

Any advice gratefully received, especially not too technical, have just learned to mend a puncture but that's about it!

Thanx.

skyd0g

It's probably just an adjustment of the cable tension that's needed.

There's a guide that you can follow here: http://www.parktool.com/repair/readhowto.asp?id=75

onbike 1939

It's important with a road triple to follow the sequence of adjustment given by Park, exactly, as these triples are a pig to set up without chain rub. Heaven knows why indexed FD's ever became popular as the obvious choice is friction for the front.

keef66

It can work well, my 105 triple does, and with very little chain rub. I didn't set it up though, that's the way it came from Epic, and all I've done is take out a little cable stretch.

Park Tools or consult Shimano tech docs. It's important to start from scratch and follow the correct sequence.

careful

Sounds like cable adjustment as 105 LH levers are the same for double and triple. This sort of problem can happen if you have the cable too tight. From the small ring, does one click take you to the trim position (still on the small ring)? If it takes you straight to the middle ring then the cable is too tight and can give the problem you describe when going from large to middle.

AliR

Thanks for all the replies, and it's been useful reading a similar thread I've just found. Incidentally, does anyone know if Shimano 105s have always have the same left shifter for triples and doubles. My bike is 2003 with 9 sprockets.

Thanks again.

Ali

giantsasquatch

It imperative the rear mech is setup correctly before attempting to adjust the front mech.

http://www.bikemagic.com/news/article/mps/uan/2955

skyd0g

giantsasquatch wrote:

It imperative the rear mech is setup correctly before attempting to adjust the front mech.

http://www.bikemagic.com/news/article/mps/uan/2955

No it's not imperative, it is preferable. As the OP does not complain of any issues in respect of the rear mech, he can safely disregard giantsasquatch's ramblings.

avoidingmyphd

fd's are not difficult to set up, even on a triple. all this stuff about "imperative to do this that and the other" is a bit overblown!

just follow the shimano instructions, here: http://techdocs.shimano.com/media/techd ... 603724.pdf

you'll see your problem in the troubleshooting chart bottom right. the solution is listed as : "Loosen the outer casing adjustment barrel counterclockwise (1 or 2 turns)."

But why not just do it all from scratch. It'll take 5 minutes and, yes, you need to do it in the right order (wow, 4 steps!!). but don't let anyone fool you that that is some crazy onerous requirement.

Steve I

Agree with a lot of the above. You just need to set up the FD from scratch, but don't pull the cable too tightly before clamping it. The cable needs to have a little slack in it at this stage. Shimano front mechs are a doddle to set up if you follow the set up instructions.

desweller

I'd strongly recommend getting hold of a workstand for mech fiddling. It makes it all so much easier!

I think the left hand shifter is the same for triples and doubles for 105 - it is on my 10-speed version anyway. I had the same problem as you, I just increased cable tension a little at a time until it went away.

You may find that, if the settings won't stay set, you may have a fraying cable, so check the condition of the cable (esp. within the shifter, it's the most fiddly place to check but a failing cable in here can lead to bits of wire falling into the shifter, which is bad :-( ).