Kick Scooter riders use a lot of energy
overcoming inertia when kicking off.
This scooter has a spring under the deck
which stores the energy usually lost in
braking by loading the spring when you let
out a rear wheel clutch. When you start up
the spring helps drive the rear wheel to
make your takeoff easier.
You could use the deck itself as the spring
but you would have to have the gearing
very high, or you would end up standing
on a tall humped deck.
This could also be done with a compressor
and an air tank, but the spring seems
simpler.