Suicide Fixed Cog
By Brad Quartuccio
Pictured above is a fixed cog installed on a hub with freewheel threading, using a bottom bracket lockring. This looks similar to a proper setup, but mechanically it’s risky business.
Even with the widespread availability of track hubs with proper reverse thread lockrings, there are still people out there running what those in the know refer to as a suicide fixed cog—a fixed cog secured on standard freewheel threads with a bottom bracket lockring. If the name didn’t give it away, a suicide cog is not a good idea. While countless people have managed to successfully run such a setup without catastrophic failure, plenty of others have spun the cog off of the hub at just the wrong time, risking life and limb all to save less than a hundred dollars.