Wildwood 

And the bicycle cockpit is so much cleaner without gadgets.

i measured and tracked things back when I was in my 40s. But electronics free for more than a couple of decades. I know the mileage of most of my rides, so that familiarity is my own calculator. The body can speak loudly at age 70 when it wants to tell something, all I need do is listen well. But i’m in the lucky category for physical health.