Shimano Dura Ace DI2 In Use

Long term usage is needed to say whether there are any issues to be found with the Shimano DuraAce DI2 electronic shifters, because they work so darn well that I never want to go back to mechanical cable shifting.

I tried to make the shifters fail— rapid shifting up and down, shifting front and rear simultaneously, shifting under severe load, etc. Eventually I succeeded in (by accident) dropping the chain off the small front chainring— once.

With the SRM power meter cranks, the planar precision is a little less accurate than with straight Shimano Durace, so a little fine-tuning was needed to avoid chain rub when in the big ring. I doubt this would happen with standard Shimano DuraAce 7900 chainrings.

Bottom line: DI2 can shift faster and more reliably than any mechanical cable system. Not once did it mis-shift or hunt for a gear. Presumably that’s because there is a known force to be applied, and DI2 just gets it done perfectly each time.

I wouldn’t buy a bike without DI2 now that I know how well they work.

Shimano DuraAce DI2 drive train on Trek Madone 6.9 SSL