WTB Proterra Tough i30 Wheel Rear 27.5'' / 584 Holes: 32 12mm TA 148mm Disc IS 6-bolt Shimano Micro SplineProterra Tough i30 wheels keep the trail in check while everything else blurs by in the periphery Reinforced by our proven Dual I Beam support 30mm internal rim width High quality EZO bearings Choose Proterra when you need a wheel that won't let you down Trail Enduro TECH SPECS Axle Type 12mm TA Freehub Body Shimano Micro Spline Hub Spacing 148mm Position Rear Rim Color Black Rim Construction Double wall Rim Drilling F: 21 R: 24 Rim Internal Width