Vaporfly is actually heavier than some other racing flats that have performed worse, like the Nike Zoom Streak 6. So your theory of what is happening doesn't fi

Vaporfly is actually heavier than some other racing flats that have performed worse, like the Nike Zoom Streak 6. So your theory of what is happening doesn't fit, unfortunately. Regenerative braking makes cars heavier and generally only returns 4-5% energy, but you don't see people demanding their electrics don't have it, do you? This is the same sort of thing for running shoes, but with energy returning foams and plates making their weight worthwhile for improving effectiveness instead.