Stan's NoTubes Bead Socket Technology (BST)
Bead Socket Technology rims are designed to match the shape of your tire's bead to create a safer and more secure air tight interface. Unlike the secure “socket” of a BST design, conventional rim shapes drive the bead of the tire down deeper into the rim, putting pressure on sidewalls that causes friction, restricts tire volume, and keeps the interface from forming a sufficient seal for tubeless use. BST rims secure the bead of the tire, not the sidewall, creating an air tight seal while allowing the tire's sidewall to expand to its true, rounder, more effective profile. The result is more traction and less rolling resistance. With lower-profile, less vulnerable sidewalls, our BST rims are also lighter and stronger by design, and accelerate more quickly.
KEY DIFFERENCES BETWEEN BST AND BST-R
Our BST system was developed specifically for tubeless use with pressures below 45psi. From our Iron Cross to our Hugo, we offer low pressure BST rims for tires in the 32mm to 122mm width range. The broader pressure range of our BST-R Series rims and wheelsets means they're optimized for tubeless use with tires in the 32mm to 50mm range at pressures of 45psi or lower, as well as 25mm to 32mm tires specifically designated as "tubeless" that feature reinforced beads designed for pressures up to 115psi. Both BST and BST-R rims and wheelsets may be used with tubes.