Originally Posted by
Homebrew01
Wait, you are in the 29 and small ring, then shift to the big ring ?!?!?
That's rubbing the cage while the chain is trying to shift to the big ring ??
Don't do that, shift the rear out of the 29 a few gears (25, 23 ...). Then shift to the big ring if you need to when you have more speed, and there will be less load on the FD and chain.
When shifting to the big ring, I am generally on the middle of the cassette. The rub is just in the big/big combo. The issue was that in raising the FD until the rub was eliminated, the chain would dump off the outside of the big ring (when shifted in the middle of the cassette as normal). A reasonably happy medium was found, but still not happy with chain rub (even big-big) on a four figure modern group.