Absolutely horrific drivetrain noise, slipping, scraping, clicking, its horrendous! Small ring at the front big two cogs at the back sound so bad, suppose its the angle of the chain leaving the small pulleys? Also middle of the cassette either small ring or big ring produces the same awful scrapey sound. Had it to 2 different bike shops (if you class evans as a bike shop) and their answer is just gunk it up with wet lube and grease.
It's a bmc slr02 with ultegra di2, I think this 11sp compared to 10sp has got to be setup absolutely perfect and mines not, so sad
I'm contemplating going back to 10sp it's that bad.