Help adjusting front derailleur - Trek 1.5
 

I have a slight problem.

When I drop to the small chainring on the front three sprockets, I have had the chain go completely off and drop into the frame three times this week. I also notice I need to have the trim clicked to the slight trim position all the time or I hear chatter. This makes me thing I need to adjust the deraileiur to the outside just slightly.

I have had the bike since June and have put over 500 miles on it, so it doesn't surprise me it needs an adjustment.

Take it to the shop? Or adjust it myself? If anyone can tell me what screw to turn, I'll give it a shot. I'm a pretty decent mechanic when it comes to motorcycles, so I'm not afraid of wrenches.

What rear gear are you in when you hear the chatter? Are you cross chained?

If it is just an adjustment issue, then try setting the LOW adjust screw to prevent the FD from going inboard as far.

Very cautious not to cross chain. What I need to know, what is the LOW adjusting screw on it?

There should be two screws right next to each other. One will be labeled "L" and one "H" for Low and High respectively. Tightening and loosening the screws will calibrate the corresponding gears.