The Speedline Killer Buzz 3/8" 28H Disc Hubset is an ultra-premium, high-performance BMX racing hubset, specifically designed for Expert and Pro-Lite class racers using a 28-hole disc brake setup. Unlike the silent hubs dominating the market, the Killer Buzz stands out with its loud acoustic footprint and unique mechanical design, ensuring minimal coasting drag.
The Worm Drive Internals
The rear hub utilizes a proprietary Worm Drive mechanism (similar to a limited-slip differential) instead of the traditional ratchet-and-pawl system.
Simultaneous Engagement: All 72 teeth engage simultaneously when pedaling forward, eliminating the risk of skipping pawls under heavy gate-start loads.
Micro-Adjustments: With 72 points of engagement, riders enjoy a solid connection every 5 degrees, enabling precise crank-positioning adjustments on the starting gate.
Zero Coasting Drag: Internal springs fully disengage the driver from the ratchet rings when you stop pedaling, resulting in minimal rolling resistance and allowing maximum momentum through rhythm sections and corners.
Key Technical Specifications
Drilling & Disc Class: 28-hole (28H) configuration, optimized for lighter Expert-sized race hoops. The rear hub body features a standard International Standard (IS) 6-bolt disc mount.
Front Axle: Pro-size front shell compatible with standard 20mm thru-axle forks, maximizing front-end steering stiffness.
Rear Axle Setup: Includes adaptable hardware for standard 3/8" (10mm) frame dropouts, with conversion hardware for 15mm frame slots.
Driver Material: Lightweight, high-strength 7075-T6 aluminum driver body with a Shimano-compatible splined pattern. Comes with a heat-treated Chromoly 16T rear cog and lockring.
Component Weights: Front hub weighs 150 grams, and the rear disc-specific hub weighs just over 400 grams.
Hub Dimensions for Custom Spoke Calculations
For those lacing these hubs to a 28H rim (e.g., Excess XLC or Dangerboy rim), use the following official center-to-flange measurements:
Front Hub:
Spoke Hole Center (PCD): 47.9mm
Flange to Center: 32.0mm
Total OLD Width: 100mm
Rear Disc Hub:
Drive Side PCD: 57.15mm
Non-Drive Side PCD: 57.15mm
Drive Flange to Center: 28.25mm
Non-Drive Flange to Center: 21.5mm
Total OLD Width: 110mm
This hubset is the perfect choice for BMX racers seeking unparalleled engagement, precision, and efficiency on the track.
