Dangerboy Decimal Chromoly Cog – Onyx / Oversized Freehub Compatible 15.3 - 18.8

*New heat-treated cogs are now black. Updated product photos coming soon.

Dangerboy Decimal Chromoly Cog – Onyx / Oversized Freehub Compatible

Specially developed for BMX Racing, the Dangerboy Decimal Chromoly Cogs are engineered from heat-treated stainless steel to deliver maximum strength, precision, and long-term durability.

Each cog is CNC-machined to exact decimal sizing, allowing fine-tuned gearing adjustments for elite riders who demand precise cadence control. The 5 mm wide inner base ensures a secure, solid interface with Shimano-compatible HG freehub bodies, minimizing wear and improving power transfer.

Specifications:

• Material: Heat-Treated Chromoly Steel

• Process: CNC-Machined

• Finish: Raw Stainless Steel with Laser-Etched DB Graphics

• Sizes: 15.3T, 15.8T, 16.3T, 16.8T, 17.3T, 17.8T, 18.3T, 18.8T

• Chain Compatibility: Full-Link Chain

• Driver Compatibility: Onyx / Oversized Freehub Body

• Base Width: 5 mm

Highlights:

• Decimal sizing for ultra-precise gear ratio control

• CNC-machined for consistent chain engagement

• Heat-treated Chromoly construction for maximum strength

• 5 mm wide base for improved stability and torque transfer

• Raw finish with laser-etched DB graphics

The way to calculate a decimal cog is to interpolate between two whole cog sizes.

For example, with a 44 / 16 gear ratio, if you’re considering a 16.3 cog, you:

• Take the rollout difference between a 16T and 17T cog

• Then subtract 30% of that difference from the 16T rollout (since 16.3 is 30% of the way to 17)

This gives you an accurate estimate of the effective rollout for a 16.3 cog.