This spring I posted about a mistake I made: purchasing a Billy Goat Contour 24" high wheel mower. To try to get it to work better I decided to increase blade tip speed. The listed speed is 12180 fpm with a 5.5" pulley above the blade. I changed to a 4" pulley and a belt 3" shorter, which should raise bts to 16748 fps, assuming no decrease in engine rpm. It cuts much better, but certainly not well enough to recommend it. Should I go to a 3.5" pulley? How fast is safe? If there is no decrease in engine speed (not likely) bts would rise to 19140, but I would bet it would really be around 18000.