Unfortunately you have an unusual hub that does not lend itself to what you want. If you're willing to relace your wheel here's an option for $22. The other nice thing is this hub has sealed ball bearings. Use some LocTite when you screw on the correct adapter. Make sure the rotation of the sprocket tries to tighten the adapter. If it tries to losen it you'll need to drill a hole through the adapter and into the hub in which you can hammer a roll pin. This will lockit in place forever.