i didn't even go as far as a lockring or loctite, which admittedly is kind of scary. I just screwed the cog on, and it's offset in such a way that it's too wide to fit a lockring on there. I locked it down pretty well with a chainwhip. When I ride I pretty much don't use the brake; I usually skid or skip the wheel or something like that. No problems yet. Just remember to keep an eye on your bike.