I don't do it nearly as often but I overhaul (clean, new balls, grease, adjust the bearing clearances and oil the freehub body) my Shimano and Campy hubs at 7500 - 8500 mile intervals or about every two years on the two bikes I ride the most. Thus far I have 50,000+ miles on a Campy Chorus front hub, 40,000+ miles on a set of Shimano WH-R560 wheels and over 72,000 miles on a FH-7700 Dura Ace freehub. All of these hubs still have the original cones and races and the original freehub bodies still work perfectly.