Since 2007, the Flow rim has been helping riders progress, push boundaries, and do more on their bikes. The original Flow was light, wide, tubeless, and strong as hell. It redefined mountain bike rims and played a role in the evolution of riding. Today’s Flow MK4 continues the progression with a 30mm wide asymmetric rim designed to build an even stronger overall wheel. Durability and an almost uncanny feeling of control on the trail have made Flow rims the preferred choice of multiple Red Bull Rampage riders, and today’s Flow goes even further. The Flow MK4’s reinforced spoke bed, combined with the offset drilling of the asym design, builds into an incredibly durable wheel that brings added confidence to every ride. Unlike many asymmetric rims, the Flow MK4’s BST Asymmetric shape is designed to equalize resistance to dents and tire bead retention on both sides of the rim under even the worst rock gardens and hardest cornering. Combined with Stan’s patented Bead Socket Technology, the Flow MK4 rim offers the easiest tubeless setup and most reliable airtight performance on the trail. Ramp up your progression and make every ride even better with the confidence of Flow MK4 asymmetric rims.