Tiagra Front Levers

I have triples on my compact set up and have to do the same.

I've got a bike with Tiagra and it has trimming via a small click. The outer takes two small clicks or one big click to drop to the inner. When I first had it, it took one click - it wasn't set up properly then.

Shimano's tech docs section has pdfs of how of this works. Quick quote from one: "When lever b is operated, there is one click where trimming (the noise prevention mechanism) engages, and second stronger click when the gear shift stroke is completed. After trimming, the next push will complete the gear shift stroke".

All it does is to provide two front derailleur positions for each chainring - one best placed to avoid chain rub for the outermost gears and one best placed for the innermost ones.

Edit:

With the large lever fully clicked on the outer chainring, a single small click on the small lever should move the front derailleur slightly towards the frame but still leave it on the outer chainring. A second click should drop to the next chain ring. This is then trimmed by a small movement and click on the large lever.

if the front deraillleur cable tension is incorrect, the highest position using the large lever is never reached and it drops to the inner on one click.

The sight guides are handy for checking this - the red bar shouldn't be central in each segment but at the left or right of it.

John

Is it normal for the change from large to smaller ring to be difficult ?
I have to give it a fair bit of force to change.

SgtFinaldo wrote:

You really have to push the black shifter hard, way past the click limit.
It aint dura ace........
But it works!!

This kind of ties in with the trimming issue - two small clicks when in the highest trimming point and it shifts easily to the next ring. If you want to go straight down to the next ring when you're in the highest trimming position then it's one big movement of the small black lever.

I don't have to push mine very hard at all - just move the lever further than the movement needed for one shift.

Same principle as the rear derailleur - shift one gear\position with a small click and two with a bigger one.

http://tinyurl.com/mcso4y has the lever positions.

John

I also have tiagrs triple shifters on my double. Am having all kinds of problems with it. Have got it shifting, but it doesn't sound good. Very clunky. Had to mess with it after it jammed up completely trying to shift down under power.

I don't really know how I should be setting them up. Should I be adjusting the lower limit screw with the shifter clicked all the way down, as if I was on the smallest chainring of a triple, or as if I was on the middle ring?

Someone can leap in if I'm wrong but I think you set the limit screw as if the smallest ring of a double were the intermediate ring of a triple.

That way, when you change up, you can't force the lever past its highest chainring position and damage it when it's stopped by the limit screw of the front deraillleur. When you change down, this doesn't matter as all you're doing is releasing the cable tension - you can't damage the shift lever by somehow forcing it against the lower limit screw.

Hope this makes sense.

John

therichieboy wrote:

Good question- don't know the answer. Be careful with that forcing the lever- that's how I broke mine.

if it does jam don't force it back, just release the cable at the mech, then use the shimano tech doc (or park tools guide etc) to set up from scratch to stop it happening again