I've been trying to solve a problem with my wife's bike. The shifter for the front derailleur is difficult to push.

It's a Trek with Shimano triple 105 shifter and FD. The bike has about 5000 miles on it, and worked fine until about two weeks ago. Here's what I've done so far:

Replaced the chain
Replaced the cable and housing
Cleaned and lubed the BB guide
The derailleur itself was sticking so I worked some WD40 into it until it was moving easily and then lubed it.
Adjusted the cable tension so that there is just enough tension to shift through the gears
Disconnected the cable to see if the shifter moved easily without being connected, and it did.

We brought it to the LDS where she bought it. They adjusted it and said it was "within parameters". The thing is, I have the same set up on my bike and it's much easier to shift.

I'd appreciate any suggestions.

As parts get old they collect grit and wear a bit. You've dealt with almost all the easy points, cables/housing, pivots, cable guides. But what first stood out is the lack of shift pod lubing. I suspect that with the cable disconnected from the der but held in your hand you'll be able to move the shifter through it's range easily. Is this the same if you're tugging on the cable with some real effort? Like the der return spring does? I wonder in internal friction in the shifter is adding the resistance your wife feels. BTW do you also feel the greater effort to throw the lever during riding? Andy.

How easily does the derailleur move if you skip the shifter and just pull on the cable?

Thanks for the responses. I just tried disconnecting the cable and holding it with pliers while I shifted. It seemed easy. I tried just pulling on the cable, and it seems a little easier on my bike than on hers. It's a little hard to tell though. So this all suggests that the problem is in the FD itself. I worked a bunch of WD40 into it, and it seems to be moving OK. What else can I do to test it. Should I just replace it? They're not all that expensive.

What is "shift pod lubing"

Is the shift wire correctly routed under the clamp screw? It generally needs to go OVER the little tab which sticks out next to the screw, before going under the screw head. Installing it on the other side will change the shifter throw and increase the effort needed to pull the wire.

So, I looked at that last reply and thought, well duh, of course I routed it over the tab, I know to do that. Turns out, not so much. That fixed it. I feel dumb, but my wife thinks I'm a genius for fixing something the LBS couldn't. Thanks dsbrantjr.