WHAT’S THE DIFFERENCE BETWEEN SDM AND RDM MASTS?
The answer: The primary difference is RDMs (Reduced Diameter Masts) are narrower in diameter than SDMs (Standard Diameter Masts). So much so, their narrowness requires a skinny (RDM) base extension.
Choose a SDM mast for sails 6.5 and larger.
Sails in this size range typically demand masts 460 centimeters and longer. A standard diameter mast offers stiffness and weight savings best matched for these large sails.
SDM Masts (fat masts)
– Stiff, lightweight and durable
– Best for flat water, 2-25 mph wind speeds, and sails 6.5 and larger
– Primarily available in 430, 460, 490 and 520 cm sizes
– Requires a standard (SDM) mast extension pictured below
Choose an RDM mast for sails 6.4 and smaller.
Sails in this size range typically demand masts 430 centimeters or shorter. A reduced diameter mast offers unrivaled durability for the higher winds these sails are commonly used in.
RDM Masts (skinny masts)
– Virtually unbreakable
– Best for flat water and waves, 12-45 mph winds, and sails 6.4 and smaller
– Primarily available in 310, 340, 370, 400 and 430 cm sizes
– Requires a Skinny (RDM) mast extension pictured below
Are There Exceptions to the Rules Above?
Yes. A few sail makers recommend RDM masts in sail sizes larger than 6.5; riders in surf locations should opt for the durability of RDM masts, even for sails 6.5 and larger.
Do Skinny (RDM) Masts Require a Different Mast Base?
Skinny masts call for a Skinny Extension, but the mast base – the piece that attaches to the rig to the board (pictured above) – fits both skinny and standard diameter extensions.
Other questions?
Masts are nuanced, and a vital rig component to squeezing the most fun out of each and every windsurfing session. The above offering is a basic overview. Don’t hesitate to contact our mast experts or call 541 386 6086.
Eddy Patricelli was the editor of WindSurfing magazine from 2001-2007. He has been sailing the Gorge for 20 years. See his best video tip for getting your kid hooked on windsurfing here.
