In theory you don't need a lock ring on the track as you'll never be resisting the drivetrain hard enough to undo the sprocket.
@andyp started
London Fixed Gear and Single-Speed is a community of predominantly fixed gear and single-speed cyclists in and around London, UK.
This site is supported almost exclusively by donations. Please consider donating a small amount regularly.
In theory you don't need a lock ring on the track as you'll never be resisting the drivetrain hard enough to undo the sprocket.