US Bases

US Cup (US) Mast Bases (Base) are compatible with US mast extensions. The Mast Base is the connection between your rig and your board. We sell bases from Chinook, Streamlines, Aeron and Bic. The base has a flexing universal joint (UJ) in the middle to allow 90 degree flex and 360 degree rotation. US cup are available in; three UJ types: Rubber, Mechanical or Tendon; three board connection types: One-Bolt, Two-Bolt or RSX mast track pin. Tendon UJ deliver most direct performance, Mechanical provides direct and easiest connection, while Rubber UJ provides more shock absorbing qualities.