This is the "500EX Key Hub". It is a slightly different version of the 500 Key Hub. It is manufactured differently, as it is extruded. Also, there is a 1.124 in. diameter boss on each side of the hub flange, providing a location for 1.125 in. bore flat sprockets. Are you having a hard time keeping your sprocket concentric with your hub? This hub is the trick.
- Bolt Pattern: 0.204" diameter holes, evenly spaced on a 1.875" diameter bolt circle
- Bore: 0.502-508" diameter bore, with 1/8" keyway (2)
- Material: 6063 Aluminum
- Outside Diameter: 2.25"
- Weight: 0.1 lbs