The Answer Holeshot Expert cassette hubs feature lightweight CNC machined aluminum hub shells with laser-etched logos, precision sealed Japanese bearings throughout, 14mm hollow aluminum center axles with 3/8″ x 24tpi chromoly axle bolts and a 6 pawl aluminum driver with 16T Shimano style cog. Each driver pawl has 3 individual teeth that engage every 3 degrees for near instant engagement and off the line acceleration. Weight: 545g (pair) Front Hub SpecsCenter Axle: 14mm Hollow AluminumAxle Bolts: 3/8″x24tpiHardware: AluminumHub Shell Bearings: 15268 (x2), verify bearing number on side of rubber sealWeight: 182gPCD: 40mmLock nut to flange: 19mmAxle width: 100mm Rear Hub SpecsCenter Axle: 14mm Hollow AluminumAxle Bolts: 3/8″x24tpiDriver: Aluminum w/ Shimano Style 16T CogDriver Bearings: 6902 (x2) Verify bearing number on side of rubber sealDriver Pawls: 6 Pawls w/ 3 Teeth Per PawlDriver Spring: Individual (x6)Hardware: AluminumHub Shell Bearings: 6902 (x2) Verify bearing number on side of rubber sealWeight: 363g w/ 16T cogDriveside PCD: 58mmNon Driveside PCD: 45mmDriveside lock nut to flange: 30mmNon driveside lock nut to flange: 28mmAxle width: 110mm