Stan's Notubes created the Alpha 400 rim for those wanting a tubeless option for road and cross with more durability than the Alpha 340. Anyone hard on wheels or over 175 pounds should probably opt for the 400 over the 340.
The ZTR Alpha 400 shares the same dimensions and Bead Socket Technology as the Alpha 340 but adds the triple channel and internal arch design of Stan's nearly invincible Arch EX and Flow EX rims. The ZTR Alpha 400 offers a 33% thicker spoke bed than the original Alpha 340 rim for maximum durability. Light and fast on the outside, ultra-stiff and strong on the inside makes the ZTR Alpha 400 a rim many riders have been waiting for.
Notubes Bead Socket Technology means a more secure seal between tire and rim and a proper tire profile for lower pressures, faster cornering and less rolling resistance. BST rims also accelerate faster, thanks to shorter, lighter sidewalls. When combined with specific road Tubeless tires, the Alpha offers a ride normally only found with tubular tires and rims, but maintains the simplicity and low maintenance of a clincher. The Alpha rims can also be used with a standard clincher tire and inner tube.
Rim tape, valve stem and sealant are needed for tubeless applications - not included. Suggested tape 21mm