Surly Track Cog 1/8'' X 18t Silver

Surly Track Cog 18T 1/8in Silver New 415 Chromoly Steel

Engineered for track cycling, this 18-tooth cog pairs with 1/8" chains to deliver reliable, repeatable engagement during sprints and tempo laps. The gear is ideal for fixed-gear and track builds that demand crisp power transfer.

Specifications and materials

Material: 415 hardened chromoly steel with a durable silver finish. Size: 1/8" (0.125") chain. Teeth: 18. Threading: 1.375" x 24 tpi, right-hand. Fits track hubs; BMX/freewheel hubs exist in the same threading but are not recommended for this application.

Performance and use cases

Best used on track hubs where precise, long-wearing engagement matters—ideal for velodrome laps, time trials, and single-speed street rides that demand consistent performance and longevity.

Installation and care

Thread onto a compatible track cog lockring. Keep threads clean, apply a light grease, and avoid cross-threading to preserve life and ensure smooth retention during high-torque efforts.

Why choose this cog

Surly’s 415 chromoly steel offers sturdy wear resistance and durability under high-torque riding. The standard BMX-style threading keeps retrofits straightforward while maintaining true tracking and alignment on track hubs.