Serpent 903813 Lightweight 2-Speed Shaft Adapter for Viper 990 GP  [SER903813]

Tune the Viper 990 GP with the Serpent 903813 Adapter

The Serpent 903813 lightweight mounting screw adapter is a precision part made for the Viper 990 GP lineup. It trims rotating weight on the 2-speed shaft to improve balance and help the gearbox shift more consistently on race day.

Smoother Shifts and Better Balance

Made to tight tolerances, the Serpent 903813 fits the Viper 990 GP chassis and reduces inertia at the shaft. That lighter profile helps the drivetrain settle faster and supports cleaner gear engagement under load.

Fitment and Quick Installation

This mounting screw adapter installs simply on Viper 990 GP (SER903020) setups and is suitable for routine upgrades or pre-race servicing. A basic toolkit and correct torque are all you need to fit it and get back on track.