Trouble with 105 LH double / triple shifter

i'm looking at a friend's bike with a front mech shifting problem. there is a lot about on the internet from a few years ago with people having trouble with the 105 double / tripple LH (left hand) shifters - i assumed they would be identical in function to my ultegra shifters and have set up and serviced the bike in the past accordingly - they are not though it seems. if anyone has any knowledge to contribute i would appreciate it.

from what i can gather the shifters were for a period designed to be used on either double or tripple chainring set ups (and so allowed for the lever to move up or down 3 positions). if the front mech was set up on a double chainring but with the gear lever in the first position, the lever would allow you to shift up twice, once onto the big ring, and once, perhaps inadvertantly, again beyond that - limiting the derailleur would stop it pushing the chain off the ring, but the cable tension would be increased enough to fuck up the shifter and sometimes lead to the inside rachet mechanisms failing.

to set them up properly on a double chainring, i'm guessing you need to start fitting and adjusting the front mech with the shifter in the second position. you could then inadvertantly shift down an extra click but without causing any problem as the derailleur limiter screw would stop you chain from being pushed off and the cable would just be a bit slack.

is this right....? am gonna see and play with the bike tomorrow anyway.

Remember about the trim shift so u end up with 3 cliks

its defo a double / tripple combined - model nb is st-5600 - the lefthand double only is st-5601

also has five clicks: (trim - middle ring - trim - big ring - trim) i think.

I have no experience of setting up Shimano, but this is what would make sense to me -

Start with shifter in the natural position (no cable attached), and set the inside limit to match the inside ring.

Tension and clamp the cable so that the first click moves the mech (rather than just take up slack in the cable)

set the limit to the outer limit required

the problem with that is that (being tripple compatible) the shifter can go up another click, and tighten the cable accordingly, the result being (with the outer limit screw set for a double) that the cable is put under a fuck load of tension which leads to the shifters mechanism failing.

... and its easy to go up that extra click by mistake.

carosn -i'd say it's much better to have extra slack in the cable than tesion. whether you get that to work in practice is harder as you'll have to shift up then up again (maybe twice) if you go down by accident - i know they can be a pain, indexing the front mech can be a pain even with all the 'correct stuff'. i can often get a mech to work on a triple with only 3 positions being need, despite what cog the chain is on - so i'd find the trim to be superfluous. and there's tons in there to break. bar end levers (with a felt tip mark showing the position for the middle ring ) all the way for me

You are correct in your first post however I would personally set it up as usual but then again I would take care not to force the shifter it depends how hamfisted you friend is. As you state if in any doubt it's better to have the cable too slack, it will be an annoyance as number6 states but will not damage anything.

The internals are made out of plastic.
As said before, using the double-triple l/h on a double only, due to Shimano's outer very likely to get substantially compressed, when moving "small ring-->big ring" the shifter goes over its natural position for two rings only use, and the mechanism gets stuck. In fact, is always hard to click on th inner lever to release the cable. If this happens, the inner lever should not be used, but the cable loosened from the fixing bolt, the setup again with the right amount of tension.
AFAIK Shimano was giving warranty on them

on the LH there should be fewer clicks - also if you peel back the hood (away from the handlebars if you imagine the shifters mounted) the black plastic is stamped with the model nb

Using the larger lever, when shifting into the big ring or braking, there is no distinction between the two planes of movement - it appears to (try to) shift and brake at the same time, unless I use another hand to steady the movement.

no idea - sorry.

Madison appear to just be replacing them - I'll be picking mine up this evening.

Any idea how to differentiate between the 5600and the 5601?

Not always. They did for a while but the last few I warrantied were fixed and returned.

I've still got some 7 speed RX1000's somewhere. Not a problem at all. All metal internals. Bloody awesome shifters.

Brand new left hand shifter now on bike. It even has "double" printed on it.

But (and there is always a but with this bike) the shifter has more float than a scoop of ice cream in a glass of coke*.

Using the larger lever, when shifting into the big ring or braking, there is no distinction between the two planes of movement - it appears to (try to) shift and brake at the same time, unless I use another hand to steady the movement.

I'm booking it back into the shop, but wouldn't mind having a go at fixing it first - Any ideas?

• I've been saving that one up for a while now.
  
  

The broken ones I've dealth with simply didn't shift down (once in bigring). So if they are broken its a new one on me.
I wouldn't try repairing it personally. If you fuck it up you're no better off.

So Carson, did you get the triple shifter to work with the double chainring in the end?

I'm trying to set up my bicycle with a double 105 chainring on the front and a triple Tiagra shifter - I managed to completely f*&k a gear cable last night while trying but I'm ready to try again!

^^^i pmed you but its actually set out clearer in this thread - my friend with the trouble bought a new shifter designed for double chainsets.