Seismic Alpha Wheels 80.5mm tall. Optimal balance of momentum, efficiency, and grip for pushing and pumping speeds! A highly-optimized balance of properties for modern racing. The fastest urethane that the skateboard industry has ever seen, bar none. The largest and most supportive hub ever seen in a wheel this size. Size and momentum to carry you past the competition in straightaways, yet agile enough for quick acceleration, fast edge-to-edge adjustments, and snappy technical pre-drifts. Available in DEFCON ultra-high-rebound formula. Vice-like grip and very snappy directional slide, with plenty of slowdown power. Ideal for aggressive racing.

A highly-optimized balance of properties for modern racing

Size and momentum to carry you past the competition in straightaways – yet agile enough for quick acceleration, fast edge-to-edge adjustments, and snappy technical pre-drifts. Welcome to a whole new realm of FAST!
Finely-calibrated width and supremely supported edges for smooth, predictable handling through even the hardest corners.
The very fastest urethane that the skateboard industry has ever seen, bar none.
Named after the Greek letter “alpha” (α), used in science to represent rotational acceleration.

A giant step forward in race wheel engineering

Stout S-shaped edge profile optimizes lip support, maximizes traction under extreme G’s, and ensures predictable slide initiation and hookup.
Running surface features a 0.5mm concave that pre-loads edges, heightens rebound, and enhances in-slide feedback.
Bearing seat offset 3.5% – 6.5% for progressive lip engagement and more consistent wear.

The Fusion core – integrating 15 years of advanced hub R&D

46mm tall x 44mm wide – the largest and most supportive hub ever seen in a wheel this size.
Deep, wide “saddle” profile regulates lateral wheel flex, supercharges edge support, and ensures absolute mechanical lock with the urethane.
8 lateral support beams (hollowed-out for lightness and aesthetics) form wide ridges that create unprecedented circumferential lock and rebound.
Robust bearing lugs.
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 (Aaron Hampshire pro signature wheel): Plush, velvety roll with extra edge hold, even on rough roads. Aggressive yet smooth slide with faster braking.
76A Mango: Vice-like grip and very snappy directional slide, with plenty of slowdown power. Ideal for aggressive racing.
78A Mint: Very stiff edges that give loads of grip with a friendly slide and crisp hookup. Ideal for smooth roads and lighter riders.

Available in finely-tuned widths:

80.5mm tall x 61mm wide DH Race
Superior top-end roll speed, traction, and braking power… with surprising quickness and agility for a wheel of this heft!
60.5mm running surface
Bearing seat offset 3.5%
Square outside edge, straight-cut inside edge
9.125 oz. each

Seismic Alpha 80.5mm 74a Defcon Wheels - Plum (Set of 4)