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 & stiffer suspension suspension pivots shorter chainstays & enhanced frame clearance. Full carbon construction coupled with Dynamic Balanced Lacing (Giants wheel technology that means wheels are tensioned to reach balanced tension under acceleration & braking forces) deliver enhance braking performance stiffness for precise handling & efficient pedalling power transfer plus low weight for snappy acceleration. Wider 21mm inner rims allow you to run wider tyres and XCR 1s are tubeless compatible so you can gain all the benefits of running tubeless tyres with lower pressures for enhanced traction reduced rolling resistance & reduced risk of flats. Ultra-light full composite 27.5” rims Tubeless compatible using supplied rim strips & valves 21mm inner rim width for better tire performance Sapim Laser/ Sapim Race spokes; 28 front/rear Dynamic Balance Lacing for enhanced drive efficiency & braking control Alloy locking nipples Boost 148mm rear / 110mm front Giant Alloy hub shell 6-bolt disc compatible DT internals 3 pawl driver body engagement Compatible with SRAM XX1 drivetrain using optional XD driver bodies 1565g per pair Rider Weight Limit: 300lbs / 136kg