My wife rides a nice little black carbon number equipped with a Shimano 105 groupset. She’s recently been complaining that changing gear with the front dérailleur has been getting increasingly difficult.
I get on the bike and can’t find anything wrong! However, when she says that she’s getting signs of arthritis in her left hand I start to take notice.
First thing I checked was that the cable was running smoothly. On this well maintained bike that is only ridden in good weather there was no problem there. It is known that the 105 front dérailleur has a stronger than average return spring and that strength can vary somewhat from unit to unit. After comparing the action of this dérailleur with other models it did indeed have a remarkably strong return spring.
Simply changing to an Ultegra model fixed the problem.
I did think for a moment this was just a ploy to get me to fit Di2 on the bike!