I have had etap for a couple of months and have been having a problem with the fd. I have a full sram red set up. All worked well when first fitted by lbs. Then after about three weeks and a couple of hundred miles the chain started to come off when changing to the big chain ring. Not everytime. About three times in a ten mile ride.
Lbs checked fd set up and set the limit screw a bit closer. This seemed better but the same problem recurred. Took it back and they sent fd back to sram. Sram said nothing wrong with fd so it was refitted and set up again.
Worked for a couple of weeks then today chain shipped at least 12 times in 25 miles.
I checked the limit screw and the gap was to my eye about 2mm instead of.5 So I turned the screw half a turn. Tried it on the stand - worked fine. On the road it would not change so I turned the limit screw back a quarter.
It now changes fine but after a few changes it still came off!
After riding up and down the road for ten minutes changing up and down it came of twice.
I cannot work out what is wrong. When it changes correctly it is so smooth. Under pressure, free wheeling, up hill, on the flat, down hill makes no difference. Then it seems to clatter and of it goes onto the crank for no reason.
Any ideas?