Why carbon plates changed racing flats

Pace Lab builds the Tempo around a plate that is stiff in one axis and compliant in the other.

A carbon plate does not return energy the way a trampoline does. It stiffens the toe joint so less energy is lost bending it, and it does that best when the foam underneath is thick enough to give the plate something to work against.

That is why plated shoes feel dead at slow paces. Below a certain cadence the foam never compresses far enough for the lever to engage.

Pace Lab publishes the plate stiffness per size, because a size 7 plate in a size 12 shoe is a different shoe.