You need to remove or at least loosen the lock ring before tightening the cog. Quite a few times I've loosened my lock ring and find my cog (which hasn't moved at all) is really loose.
@M_V 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.
You need to remove or at least loosen the lock ring before tightening the cog. Quite a few times I've loosened my lock ring and find my cog (which hasn't moved at all) is really loose.