Pancho, it not so much the riders are at fault ( although i have seen good Dt ridrs not able to stay upright on the speedway track)but the radius of the corners on the DT tracks dont suit slider lines anymore. and many track have these weirdo chicane things or stop and shoot corners, so there a long straight requiring 2 gear changes, and the a stop turn corner, they seem to cut them on an angle which is ok for MX bikes, but dont have the same flow as the slider line. If it was a Jelly bean - kidney shape would be better, but dont see to much of that. well except Griffith and fairburn park that i can think of.