I have a road bike with Shimano 105 and I'm having issue with the FD/Left Shifter. I can't get the adjustment just right. The shifter is a triple and the crankset is a truvativ rouleur double.

The problem is that I can't seem to shift to the large chainring unless I am at lease halfway through the cassette. Also if I shift down to the smaller chainring and I'm not in the lower half of the cassette the chain sort of falls between the chainrings and doesn't engage the smaller ring.

The limit screws don't seem to do anything when I turn them either.

follow park tools guide on fd adjustment

Hi, sounds like your off a click on the shifter. So disconnect the cable and make sure the shifter is all the way out or low gear. put chain in 1st gear and chain should just barely clear the inner cage plate of front deraileur with the outer cage plate parallel to outer chainring. Then remount the cable but make sure it goes over the top of the nub on the back of the front deraileur. A lot of people mount the cable between this and the bolt and the deraileur is stopped from being able to make the full throw. Then adjust for outside travel set screw if still won't through the shift to big ring far enough. GL

www.bicycletutor.com has a good video on FD adjustment.
I suggest you start from the beginning again. Lock that low limit screw so that you don't accidentally kick the FD into the small ring which doesn't exist in your Rouleur double. BTW, how is this crankset? I'm contemplating to get this or the MegaEXO.