Light weight is a considerable criterion but it cannot define a cycle product's performance by itself and it must absolutely come along with a good rigidity of the wheels as of the frames. It must also be found in the right place, especially on a wheel it is the rim which must be very light so as to provide a low rotation inertia, which helps repeated re-start-ups and accelerations during cycling. Another notion prevails, that of the design of a frame or a wheel aimed to obtain streamlined profiles.
This is how, at 40 km per hour, a wheelset with a streamlined profile can allow one to save 10% of the average power delivered by the athlete to keep this speed ; 500 gr gained over the weight of a bicycle would be valuable on a gradient but for a cyclist weighing 70 kg who rides a bicycle weighing 10 kg, which represents 80 kg in total, the energy saved on a gradient will be about 0.625%, which means that weight is no longer a drawback on a descent ...