chain drop, not enough spring tension in RD to retain the chain, my experience wasnt with etap but with 6870 and a narrow wide ring, I also did the spring tension hack that you can do with shimano RDs and this was all bumpy road .. you really need a clutched mech to run 1x
Bollocks to that. Used to run 1x 6870 off road and not dropped a chain once. Also just built a 1x etap for a customer for CX and first thing he did was ride it down some stairs as shakedown. Guess what didn't happen?
chain drop, not enough spring tension in RD to retain the chain, my experience wasnt with etap but with 6870 and a narrow wide ring, I also did the spring tension hack that you can do with shimano RDs and this was all bumpy road .. you really need a clutched mech to run 1x