I recently bought two used road bikes (for very good prices), one of them is full Ultegra (9 speed triple from 2004) but its front derailer seems to be too strong. To shift from the small chainring to the larger ones, it takes a considerable amount of force on the lever. The other bike has a 105 FD/shifter (10 speed triple from 2008) and it is normal, I don't struggle with it.
I thought at first it was the cable and housing, but if I force the derailer into the high chainring position and keep it there with a screw driver, which removes the tension from the shift cable, then the shifter moves easily, suggesting that the cable/housing is fine. The derailer really wants to shift into the smaller cog, so I feel that the spring is way too strong. Also it is a little touchy when shifting from the large cog to the middle cog, it often just skips the middle and goes to the small one due to the spring (and then you have to shift back up to get to the middle). I've also tried cleaning it out with degreaser and regreasing it, but to no effect. Does anyone have any ideas about this issue?
And apologies if this is already addressed, could not find in the search.