Gear Trim gone :(

[QuinnDexter]

Hi.

I've got a shimano tiagra groupset and after my "free" service at my local bike shop I noticed that I can no longer trim the front cage. On the selectors there is a stop for the trim but when I look down at the front derailleur it only moves a small amount compared to the travel I had pre-service. So the chain still rubs on some gear selections.

Does anyone know how to get the trim back? I was thinking it might have something to do with the upper limit screw.

Thanks

 

[fossyant]

They have probably tightened up the High and Low limit screws on the front mech (look for two screws next to each other marked H and L..... Just undo the H one slightly. You may need to adjust the cable tension so in the outer ring, the mech doesn't shift out as far so you still have a little trim.

 

[RedBike]

Set the high limit screw (and cable tension) so that the front mech moves far enough so that the highest gears run without the chain catching on the cage. Now when you trim the gear the mech will move inwards slightly allowing you to use the lower gears at the rear.


Ideally you should be able to get the front mech position so that you can access most (if not all) of the gears without the chain catching and without needing to trim the gears. The gears that can't be accessed without the chain grating on the front mech are best avoided anyway.

 

[e-rider]

Set the high limit screw (and cable tension) so that the front mech moves far enough so that the highest gears run without the chain catching on the cage. Now when you trim the gear the mech will move inwards slightly allowing you to use the lower gears at the rear.


Ideally you should be able to get the front mech position so that you can access most (if not all) of the gears without the chain catching and without needing to trim the gears. The gears that can't be accessed without the chain grating on the front mech are best avoided anyway.

Trim on Shimano works by moving the mech out slightly - not inwards!

 

[RedBike]

Oh no.
My Tiagra shifters always used to move the mech INWARDS slightly.

In that case completely ignore the bit about setting up the mech.

 

[e-rider]

not so fast; I was basing my statement on my 105 shifters assuming that they would be the same - perhaps you are correct after all

 

[Fiona N]

I'm confused - my 105 shifters have a trim 'click' which moves the cage slightly up or down when on the middle ring. So if I change from small ring to middle, another click 'up' moves the cage out, but not enough to initiate the change to the big ring, whereas a click down moves the cage back towards the small ring but, again, not enough to change chain ring. To keep these functions, the cable tension is critical. If it's too tight, the 'big click' to change from the small to middle ring, for instance, somehow overrides the small trim click so that the next lever movement up goes all the way onto the big ring.