In a bicycle race, a bicyclist coasts down a hill with a 7 % grade to save energy. The mass of the bicycle and rider is 80 kg, the projected area is 0.2 m2, and the drag coefficient is 0.9. Air temperature is 17 ºC. Neglecting rolling friction and bearing friction, determine the maximum speed of the bike if there is a head wind of 15 km/h.