Originally Posted by
meanwhile
No, you're wrong now. The guy specified a steep hill where the cyclist could only make 10mph and at this speed aero is NOT important. Power needed for work against gravity and RR is LINEAR with speed, but aero is SQUARED. Which means that aero dominates at speed but drops away to be trivial at lower speeds.
You shouldn't take the particular values in that graph as gospel - just that AR is a curve and that RR and gravity are linear.
It's important to understand this, because when you do then you understand that what is optimal for TDF racing speed is not necessarily relevant to Audax or commute speed. A TDF team uses narrower tyres with higher RR for their low aero drag, but at the speed of an Audax or commute then a wider tyre with higher AR but lower RR will be faster.
No, what I wrote was correct. At slow speed, aerodynamic drag is not important, but it starts to become important at 10 mph. But nice try.