Originally Posted by MichaelW

They will only operate road front mechs, not MTB ones so you are stuck with using a Tiagra triple shfter on an MTB chainset. It works but requires careful trimming. Unfortunately the trim function is poorly thought out and you can easily overshift esp from middle to small ring. You then need to shift back up and retrim, by which time you have lost momentum and actually need the small ring so you have to shift back down again.