For years we've worked quietly to create a better asymmetric tubeless rim. Asymmetric rims with offset spoke holes build into stronger wheels, but they've always had major downsides when it comes to tubeless. Most asymmetric rims have areas that are vulnerable to denting and don't create equally strong airtight seals on both sides of the rim. The new MK4 rims are the first asymmetric aluminum rims that we created based on our patented Bead Socket Technology. Our BST-Asymmetric design allows for the improved bracing angle and nearly equal spoke tension balance of an asymmetric rim, but resists dents and retains the easy inflation and reliable airtight seal that's made Stan's the leader in tubeless rim technology. The new MK4 series rims are available in three updated widths, and each Crest, Arch, and Flow model has its own purpose-built, wider rim shape and spoke hole offset.

Well suited for eBikes, S2 wheels are built with Stan’s all new E-sync hubs to handle additional weight and drivetrain stress. Like the MK4 series, Stan’s S2 rims have all increased in width, but S2 rims are manufactured with 6061 aluminum using a durable sleeved joint and stainless steel rim eyelets. They rely on Stan’s proven conventional symmetrical Bead Socket Technology for easy inflation.