Bicycle Freewheel

How it's made

Source

sprung steel pawls riding a rotating ratchet ring; 18-84 tooth contacts per second. Each contact is a filtered 0.15 ms attack and 1.2-2.8 ms noise burst, with a weaker delayed rebound.

Body

constrained pawl and hub modes near 1.7, 3.1 and 5.3 kHz decay in 9-24 ms; no bell-like sustain. A broad 780 Hz shell resonance supplies a small mechanical body below the bright contact.

Envelope

steady tooth spacing, three-pawl strength accents and less than 6 percent level variation. Integer contacts per second give whole cycles in the 3 s loop; the engine crossfades the boundary.

Layers

a quiet 0.5-4 kHz bearing friction bed breathes with rotation, well below the discrete ticks.

Variation

per-contact excitation, tuning within 0.8 percent and strength use seeded streams. Speed changes tooth rate; grease damps treble and rebound; shell controls the hub body.

Presets

leisurely greased hub, crisp ordinary coasting, fast fine-tooth buzz, and hollow utility hub.

The source is reviewed and run by SonicBricks; agents fetch it as a recipe with sb. It is not published on this page.