However, a fairer comparison would be obtained by considering the cyclist followed by a car with 1 bike on the roof as the reference situation instead of the cyclist riding alone, because indeed there is always a car with at least 1 bike on the roof riding behind the time trial cyclist, as shown in Fig. 2. Table 9, Table 10 hold the corresponding values. We again only discuss the results for the top time trial speed of 50.4 km/h, because these yield the smallest time gains. For a car with 10 bikes, as in Fig. 2a, the additional drag reductions compared to a car with only 1 bike are 0.32, 0.14 and 0.09% for d = 5, 10 and 25 m, respectively. This provides additional time gains per kilometre of 0.07, 0.05 and 0.04 s. For the car with the 2 bikes placed perpendicularly, the additional drag reductions are 2.99, 0.89, 0.50 and 0.36% for d = 1, 5, 10, 25 m, respectively. The corresponding additional time gains per km are 0.77, 0.21, 0.12 and 0.08 s. Finally, for the car with the vertical plate, the additional drag reductions are 4.15, 1.89, 0.99 and 0.65%, and the additional time gains 1.09, 0.44, 0.23 and 0.15 s for d = 1, 5, 10, 25 m, respectively.