Stan's BST-Asymmetric Technology
BST-Asymmetric rims combine Stan's patented Bead Socket Technology--the original and still most reliable tubeless-ready rim design--with an asymmetric shape that allows for offset spokes, creating a stronger overall wheel. Most asymmetric rims struggle to inflate easily and maintain a reliable seal on both sides of the rim, but Stan's BST-Asymmetric rims equalize tire retention and dent resistance on each side of the rim, allowing for easy inflation and total ride confidence under even the hardest cornering.
Stan's BST Asymmetric rims feature distinct spoke hole offsets based on rim width. At 25mm wide, Crest MK4 rims have 1.5mm of spoke offset. The 28mm Arch MK4 rims use an offset of 2.5mm. The 30mm wide Flow MK4 rims use a 3mm offset. This level of precision optimizes spoke tension balance and allows for the strongest and most effective tubeless rim shape. The Crest MK4 asymmetric rim, for instance, has a near perfect 92% balance between drive side and non-drive side spoke tension, versus the 58% spoke tension balance of previous symmetric Crest MK3 rims. When used with M-pulse or E-sync hubs, Stan's MK4 BST-Asymmetric allows a single spoke length to be used for all matching sets. Whether you choose a MK4 wheelset with M-pulse hub or S2 wheelset with E-sync hub, a complete set of Stan's Crest, Arch, or Flow wheels will each use only a single common and readily available spoke length that works front or rear, either drive side or non-drive side, making maintenance and service easier than ever.