105 front derailier advice needed.

everogere

I am not a complete novice at doing reapairs but this problem has got me stuck.
I have just upgraded the gears on my Spec from Tiagra to 105. The rear works great very smooth and precise. The front changer is terrible. It changes up ok ish although quite stiff but downshifting the lever feels very tight and seems to take two movements of the lever to shift the gear and when it does it goes with a heavy clunk. I am still using Tiagra levers, are these compatable with 105? I replaced my original derailier and it done the same. What have I done wrong or does this mean something wrong with the lever?
Any suggetsions?

topdude

Yes Tiagra levers are compatible with 105 mechs.
The front mech has an absurdly heavy return spring so it can feel hard to shift up and return with a loud clunk.
I have changed from the old Tiagra to the latest ones and shifting is much lighter and smoother so if you have older levers they might feel a bit stiff and clunky.
Try changing up / down by pulling the cable away from under the down tube (not while riding of course ). How does that feel, if it changes smoothly then maybe the cable inner and outer needs changing or the lever needs some light oiling inside.
Two clicks of the lever to down shift might be the trim function where you can fine tune the front mech cage to cope with an extreme chain line.
Well, they are my suggestions, hope it's helpful.