Why did Michael Rogers drop his chain?
Michael Rogers dropped his chain off the small chainring in the stage one time trial, not once, but twice, forcing him to dismount and put it back on. He was on a Scott Plasma3, as were all his teammates, and he was using a Shimano Dura Ace Di2 grouppo, the same as on all the team TT bikes. What went wrong? According to team mechanic Perry Moerman, a relatively last-minute equipment change, compounded by the nature of Di2 front shifting, conspired to cause the problem. Normally, Di2 is set up and programmed to shift perfectly between a 53- and a 39-tooth chainring.