Seismic Hot Spot Wheels 63mm x 45mm 84A set of 4. 43mm running surface, Offset bearing seat, Square outside edge, beveled inside edge. The 63mm x 45mm Hot Spot is a small, super-agile version of our 69mm and 76mm Hot Spot shapes. Molded around our advanced Mini-EC hub, it’s a light, quick, do-it-all wheel - ideal for general-purpose cruising and Tight / Hybrid slalom.