be surprised 
And I’m far from alone from reading these threads.
Obviously there is drift over time, but I tested with 6 and 8 min interval steps and it was pretty clear where I went <0.75, on several tests with different apps. I’m tempted to try a couple of longer indoor rides with Fatmaxxer and see how long it takes for the DFA1 to drift.
I should also add I’ve been a high volume rider for ~12 years, with 100,000 KM outdoors just on Strava already and loads of time spent in z2 endurance work for many years. Before that I also ran and swam quite a lot as well. I guess I have a fairly well developed aerobic system really.