by Audi1 » Tue Apr 07, 2015 7:35 pm
Sounds right to me. After I come off the Hudy, I go to 220, then 500. If I'm racing locally, it stays there; 500 is the last step. If it's going out into a proxy, I'll go higher in grit, sometimes. I've used 1200, 1500, 2000 and 2500, but I think that the benefit(s), if any, of the higher grits is more psychological than mechanical.
I find urethanes harder to put a final smooth on than silicones or rubbers. Paul Gage mentioned 4000 grit plus isopropyl alcohol as a way to put the skin back on a trued urethane tire. I haven't done that yet, but urethanes are where I do, routinely, go to 2500 grit. And, for me, it does make a difference; in the right direction, lower lap times.
Allan