They tried to race them awhile back in the Michigan area on pavement. A micro sprint (600) is not a midget frame. A mini sprint is a basic midget frame. The normal track for a 600 is a 1/6 1/8 mile track. A problem with running them on pavement is the loads in the corners. Hubs-wheels-bearing. do not hold up to the loads. For ever brand new-state of the art 600 that would show up to race you would have ten minis that are old and a little long in the tooth. So before you say go out and buy all new parts to race on pavement. Remember most racers -spend more then they can--or right at the limits of what they are doing. A street stock racer has a street stock because that is what he can race. Its not like he could have a indy car but just likes steet stocks. Its what he can do with what he has. Same for mini sprints. They have million dollars in the bank--just race 600 because they do not want to move up the ladder.I have gone around on a 1/2 mile dirt in a 600. fast-fast -fast