Is the real problem that the nut is coming loose OR that we have to keep tightening it to keep the brake and sprocket hubs tight ?? I have run stock, LSR and RPM. None of them have come loose. ALL of them have to be tightened every once in a while to adjust for wear.
I know that mine was just plain coming loose. I could make two laps around the track and would have play in the sprocket hub. Once I installed the lonestar nut, no more problems.
I replaced my axle with the lonestar axle and I couldn't keep my nut tight either. I bought a axle nut from Rad racing for $40+. Easy installation and haven't had to tighten it one time. This is the best way to go unless you have the money to go with the antifade hub. ( $180).