So after 1600 wonderful miles my bike has developed a bad habit. About every 25 shifts from the big ring to the small (50-34) the chain drops. To make matters more interesting the chain catcher seems to be pushing the chain in my chainring lodging it securely in the cut out. This has now happened twice and in order to fix it, i have to turn the bike upsided down and pull really hard to dislodge the chain from the chainring (getting nice and greasy in the process)

How do I troubleshoot this itermitten problem? It shifts fine most of the time but when it drops it gets fubared really good.

the limit screws seem to be in the right spot on the FD. I have about a mm on the low side and probably a little less on the high side.

do i have too much tension in the cable?
chain wore out?

105 FD braze on / 105 Crankset (34-50)

any ideas appreciated.

Tighten your low limit screw until the FD cage just barely clears the chain while in the small front/large rear combination. You need very little clearance, the 1mm you have may be too much.

Adjust your chain catcher until it works properly or replace it with another one which does. If your chain can get jammed it is not doing its job. I recommend the N-Gear Jump Stop for those frames which will accommodate it.

Yes, if your chain is finding space to get jammed into, then your chain catcher is not installed properly.