Originally Posted by
Amt0571
If you carried a spare, as I usually do, you could have replaced that on the road. You can't do that when a Di2 goes haywire.
BTW, if your cables are breaking twice a year, you have something wrong with your bike.
When they break inside the shifter, it's usually not a quick fix. You have to fish out bits of broken wire, which can be fiddly and time-consuming.
And I have several bikes equipped with Shimano mechanical groupsets. The newer ones, with shift cables under the bar tape, are somewhat notorious for this problem.
Di2 is not 100% reliable, all the time. Agreed. My point is that the same is true of a mechanical drivetrain, too.