Seismic Alpha 75.5×62.5mm 74a

75.5mm tall x 62.5mm wide ALPHA Wheels
62.5mm running surface • Bearing seat offset 6% • Square outside edge, straight-cut inside edge
7.8 oz. each • Sold in sets of FOUR wheels

Available in two proprietary formulas –
BlackOps™: ultimate balance of speed and grip • extreme traction fresh • buttery and smooth broken-in • comfortable and predictable
Defcon™: Guinness WR speed • directional slide • long-lasting grip • slow, consistent wear

A giant step forward in race wheel engineering. The Alpha’s stout S-shaped edge profile optimizes lip support, maximizes traction under extreme G’s, and ensures predictable slide initiation and hookup. The running surface features a 0.5mm concave that pre-loads the edges, heightens rebound, and enhances in-slide feedback. The bearing seat is offset 6% for progressive lip engagement and more consistent wear.

The Alpha™ also marks the debut of Seismic’s proprietary Fusion™ core – at 46mm tall x 44mm wide, the largest and most supportive hub ever seen in a wheel this size. Features include a deep “saddle” profile, 8 perpendicular support beams (hollowed-out for lightness and aesthetics), and robust bearing lugs. The Fusion minimizes lateral wheel flex, supercharges edge support, and assures absolute mechanical lock with the urethane. Formed from 85D fiber-reinforced thermoplastic – the toughest hub material in the industry.

Available in DEFCON™ ultra-high-rebound formula, in three finely-tuned durometer choices

Thoroughbred race ‘thane • Guinness WR speed • directional slide • long-lasting grip • slow, consistent wear

• 74A Plum (Chase Hiller pro signature wheel): Plush, velvety roll with extra edge hold, even on rough roads. Aggressive yet smooth slide with faster braking.