Description
Freewheel M30*1 – 1/2″ x 3/32″ 14T
DNP Precision Quality Freewheel
Chain Standards
The common size chain and sprocket for almost all single-speed BMX bikes is 1/2″ x 1/8″.
- 1/2 Inch Pitch: This is the distance from one chain rivet/pin to the next. Every modern bicycle chain shares this exact pitch.
- 1/8 Inch Internal Width: This is the measurement of the gap between the inner plates where the teeth of your sprockets fit. It equals roughly 3.18 mm. Thick freestyle sprockets and driver teeth are specifically machined to fit this wider, heavy-duty standard.
If you are riding or building a BMX racing bike, the standard changes to 1/2″ x 3/32″ to save weight and maximize drivetrain efficiency.
- 3/32 Inch Internal Width: This is a narrower internal width (approx. 2.30 mm)
NOTE You can run a wider 1/8″ chain on narrower 3/32″ sprockets, but a 3/32″ chain will not fit over a standard 1/8″ freestyle sprocket.
Freewheel Thread Standards
The Industry Standard: 1.37″ x 24 TPI thread pitch is the standard ISO/English/British threading specification used for the vast majority of multi-speed and single-speed bicycle freewheels worldwide.
- 1.37 inches converts to approximately 34.8 mm. However, some manufacturers label this exact standard as M37 x 24 or M37 x 24TP.
An M30 × 1 freewheel is a specialized single-speed metric threaded freewheel primarily used on BMX bikes, track bikes, and fixies with “flip-flop” hubs. The designation refers to a 30 mm metric thread diameter with a 1 mm thread pitch.
- These only fit metric M30 × 1 hub threads. They are generally designed for smaller tooth counts (typically 13T, 14T, or 15T) and are not compatible with hubs of 1.37” × 24 TPI threads.
- Generally they are available in both standard BMX chain sizes.
