Moto Tassinari VForce4R Reed Valve System KTM/Husqvarna 85 17-20
The all-new VForce4R for the KTM 85cc & 105cc and Husqvarna 85cc models offers enhanced reed petal life thanks to the rubber overmolded reed cage tips and extended reed stops, as well as all the added benefits of the unique VForce reed valve design.
The unique design of the VForce reed valve system features double the reed tip surface over a conventional reed valve design. This has two major benefits: 1) The reed petals only travel half the distance as a conventional reed valve design to get the same airflow. 2) Because the reed petals only need to travel half the distance of that on a conventional reed valve design, there is a greater chance of them being fully opened as well as a better chance of sealing when they are "closed". A reed petal never truly "closes" in a classic sense, as it is always in movement. Consider this, an engine operating at 8,000 RPM results in a reed petal opening and closing 133 times in one second. This fact, sheds light on another VForce advantage. Since the petals are only traveling half the distance, they generally last longer as they receive less wear than the reed petals on a conventional reed valve design.
Improved VForce4 Features:
All-new reed petal resin system, carbon fiber and lay-up
Pre-curved reed petal ensures better seal at tip
Wider reed cage for maximum airflow
Combined reed tip area increased by 10.5% resulting in increased total air flow
Airfoil shape added to cage tip to increase air velocity from outer ports
Long reed stops added to progressively slow petal tip velocity, for increased petal durability
Reduced frontal area of central wing by 15.6% combined with a more aerodynamic shape
KTM 85SX 17-20
Husqvarna TC85 17-20