The new Boost hub standard is certainly gaining traction in the mountain biking world and correspondingly Race Face has created the Aeffect-R Boost 27.5" rear wheel. The new Boost standard is all about increasing the stiffness of larger diameter mountain bike wheels by utilizing a wider hub axle spacing (148mm for a rear wheel) as well as a wider flange width. Boasting a 30mm internal rim width and increased strength, the Aeffect-R Boost 27.5" rear wheel is built to handle aggressive all-mountain trails as well as Enduro races. In addition to a great rim, the Aeffect-R incorporates a new Race Face Trace hub design with full cartridge bearings for extended life and durability. The hub also boasts a competitive 9.2 degrees of engagement using a durable, 3-pawl design. This hub is tough - think a Clydesdale with a motor kind of tough - and can handle whatever you dish out on the trails. Boost standard rear hub feature a width of 148mm Rear hub utilizes 12x148mm thru-axle configuration Stout aluminum rim with 30mm internal width optimized for all-mountain and enduro riding 28 straight pull, double-butted spokes in 3x lacing pattern for strength and reliability Tubeless ready Shimano-compatible cassette body 6-bolt disc rotor compatible Front and rear Aeffect-R wheels utilize just one spoke length for easier maintenance -- 5 extra spokes are included with rear wheel