Here’s what Cervelo say happened to Heather:
*“The good folks from Cervelo and an expert from Shimano took a good look at my bike this afternoon. Turns out the actual Di2 failure was a 1 in a never seen before problem with the shifting mechanism within the derailer. It had nothing to do with the electronics - the signal was arriving but the worm gear that drives the shifting was somehow broken/shredded (possibly by an impact, loads of riding, then another impact - in transition somehow? A final straw kind of deal, which is why it worked fine the day before and to start on race day, but snapped during the ride). Basically just incredibly unlucky and there was nothing I could do to fix it.”
So it was a mechanical problem. Can’t wait to see what all the mechanical/anti-electronic folks have to say.
Isn’t the wormgear peculiar to an electronic system? So yeah it is “mechanical”, but it is a fairly precisely engineered component that is only required in an electronic derailleur system, therefore a potential weakness (it seems) that you wouldn’t have in your purely mechanical setup.
That said, I’d still buy Di2 if I could afford it!! Cos of shiny.
Yes it is. Probably should have been more specific in my statement. Like you said, it was a mechanical problem but only specific to electronic systems.