Seismic Fullspin Skate Bearings with Built-in Spacers (Skateboard bearing spacing only)

About

Fullspin’s patented Built-In spacer interface is quite simply the most advanced bearing alignment tech ever seen in the skate world , full stop. Integral half-spacers with extra-wide flanged ends * (U.S. Pat. #9,126,101) square up inside wheels with more than double the contact area of ordinary Built-In interfaces – powering absolutely unparalleled alignment precision and stability . System corrects for off-spec axles and misaligned bearing seats. 1 Levels and steadies all working components of seated bearings far better than any other design (Built-In or Classic), to unleash near-perfectly optimized paired performance. Synergizes with all advanced features in individual bearings to maintain exceptionally consistent wheel contact and grip; support extremely predictable slide performance; and noticeably extend both wheel and bearing life. Built-in spacer lengths calibrated to extra-strict 0.400-inch combined width tolerance, to support highly accurate positioning of paired bearings inside finer wheels with well-engineered hubs. 2 Flange components precision-machined from premium bearing steel with advanced heat-treatment for unmatched strength, toughness, and press-fit stability. 3 Radius reduced to bare minimum on all edges (ends of flange components and extended inner rings), for fuller contact and more stable alignment at half-spacer interfaces. Inner ring bore specs dialed to maintain exceptional straightness on finer axles. Extends 0.5mm on outer (seal) side, eliminating need for washers at hanger and nut interfaces. * Note: The broad Fullspin XT Built-In half-spacer ends may not fit into hub-less street wheels with extra-thick urethane bearing supports – which sometimes leave the wheel’s central hole smaller than the flange (15mm in diameter). Choose Fullspin Classic or Fullspin LITE Built-In bearings for wheels of this kind. 1 Common issues include micro-flaws in axle diameter, axle concentricity, axle straightness, bearing seat levelness, and bearing seat spa