Not too happy with LBS
begin rant/
I was recently having problems with my chain rubbing on the FD when I was in the largest chainring and smallest cog. Turning the H limit screw didn't help, so I concluded that I needed to increase the cable tension on the FD, but I had no barrel adjuster.
Anyways, I took my new bike to my LBS and had them install barrel adjusters and tune the FD. When I get the bike back I notice that the chain still rubs some when I'm in the big ring and small cog, so I turn the barrel adjuster to increase the tension, and voila, the rub goes away.
But then I end up having problems with the chain falling off the big ring and into my cranks when I'm in the 6th cog and shifting from the small ring to the big ring, so I decrease the tension on the FD and the problem goes away. Now I'm just confused.
It turns out the FD's height was set too high, so I lowered it to the point where a penny can just fit between the big ring and the derailleur cage. Now I have the tension increased without the chain falling off.
Thing is, you'd think my LBS would have noticed that problem when they "tuned" the FD. *sigh*
/end rant