Originally Posted by
pennpaul
Totally naive question. I used Di2 on a rental bike once. It was cool. I have a bike computer (not HH). Why do I care that the Di2 and HH can talk to each other? Am I shifting gears with the HH, or is it to just see what gear I'm in? If the latter, is that feature really that helpful? Asking because I have no idea.
If you have a Di2 shifter with the "extra" button, you can use it to change the display on the computer, and the computer will display what gear you are in, what charge remains on your Di2 battery, and stuff like that.
Hammerhead Karoo users will, providing they do actually update the firmware on the date it is released, lose the ability to see their battery level, shifter mode, front and rear derailleur indications and also they will no longer be able to cycle through the data screens using the buttons hidden in the hoods.
https://www.cyclingnews.com/news/shi...m-acquisition/