Giant XCR 1 27.5 Boost are a super lightweight carbon XC wheelsystem featuring the very latest wheel technologies for a superior ride. Experience precise handling, pinpoint control and rapid acceleration. Boost technology (a wider hub standard) means a stronger spoke bracing angle deLivering riders a range of benefits including enhanced stiffness for precise handling. Bikes designed to accomodate Boost wheels have wider and stiffer suspension suspension pivots, shorter chainstays and improved frame clearance. Full carbon construction coupled with Dynamic Balanced Lacing (Giant's wheel technology that means wheels are tensioned to reach balanced tension under acceleration and braking forces) deLiver enhance braking performance, stiffness for precise handling and efficient pedalling power transfer plus low weight for snappy acceleration. Wider 21mm inner rims allow you to run wider tyres and XCR 1's are tubeless compatible so you can gain all the benefits of running tubeless tyres with lower pressures for improved traction, reduced rolling resistance and reduced risk of flats.