JB01 Boost Front Hub- Large BearingLyne JB01 hubs are lightweight, serviceable and reliable. The sealed cartridge bearing design means bearings are protected from the elements and are easily replaced when worn. JB01 Hubs are available in boost and non boost options with replaceable end caps to convert between Thru Axle and QR. Lyne JB01 hubs come in two versions, here is the difference: JB01 Large Bearing 6902 bearings (larger bearings) = longer bearing life, slightly heavier Better