Conceptually you seem correct but your numbers are a bit off. Down a steep hill on my road cycle I can easily get to 45-50mph. Rolling resistance doesn't chan

Conceptually you seem correct but your numbers are a bit off. Down a steep hill on my road cycle I can easily get to 45-50mph. Rolling resistance doesn't change that much with speed[1]. Rolling resistance energy balance at 18mph is on the order of 10-15W[2] Drag increases with the square of velocity (D=0.5 * <drag coefficient> * <representative cross sectional area> * <air density> * <velocity>^2). The drag energy balance (plus some rolling resistance) at 10, 20, and 30mph is on the order of 10, 100, and 300W, respectively[3]. [1]https://www.schwalbe.com/en/rollwiderstand.html https://www.schwalbe.com/en/rollwiderstand.html (see section "what exactly is rolling resistance") [2]https://www.bicyclerollingresistance.com/road-bike-reviews https://www.bicyclerollingresistance.com/road-bike-reviews [3]https://www.exploratorium.edu/cycling/aerodynamics1.html https://www.exploratorium.edu/cycling/aerodynamics1.html (see the calculator)