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 asymmetric design builds into an incredibly durable wheel that brings added confidence to every ride. Unlike many rims the BST Asymmetric shape is designed to equalize resistance to dents and tire bead retention on both sides of the rim under extreme conditions. 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.Low-profile 30mm internal width optimizes tire shape traction and control for 2.3-2.6" tiresDurable 6069 aluminum with welded joint and reinforced spoke bedBST Asymmetric design combines Stan&';s legendary easy tubeless inflation with a stronger more balanced wheel build3-year rim warranty with 1-year crash replacement TECH SPECS table{border-collapse:collapse;width:100%;} td{text-align:left;padding:8px;font-weight:350;} tr:nth-child(even){background-color:#f2f2f2} th{background-color:#eb212e;color:white;text-align:left;padding:8px;} .desc .specs-heading{font-size:24px;font-weight:600;padding-top:35px;border-top:3px solid #f0f0f0;display:inline-block;border-bottom:4px solid #eb212e;width:142px;margin:0;} Brake Compatibility Disc Only Rim Width (External) 33.6 Rim Width (Internal) 30 Brake Track None Manufacturer Spec ERD (mm) 561 Valve Presta Valve Length Short 32-40mm Color Black Weight 487 Wheel Size 27.5" Defined Color Gray ISO Diameter 584 / 650b / 27.5" Eyelets None Hub Drilling 28 Rim Joint Welded Rim Depth (mm) 18.9 Rim Material Alloy Tire Type Tubeless Ready Rim Center Offset (mm) 3