Reed Valve System Vforce 4R Yamaha Yz 125 2005-2019 Moto Tassinari

Vforce lamellar pack 4 R Vforce by moto tassinari
The design of the V-Force reed valves has a double surface of the end of the lamella compared to a conventional design.
The advantages are:

The lamella must bend for half the distance of the lamella of a traditional valve to obtain the same air flow
consequently it is easier to completely open and completely close the valve blades.
A lamella never completely closes being always in motion.

Consider that in an 8000 rpm motor the valve blades open and close 133 times every second.

But this fact highlights another advantage of the V-Force design.

The slats, moving for a much smaller distance, generally last much longer and wear less than the slats of a traditional valve.

Rubber coating on the surface of the valve body where the upper edge of the slats rests, to increase the life of the slats.
New design of manifold, valve body and air guides specific for V-Force4 R.