In my opinion, all 250 singles should be required to have a sprag or other axle device. Of course that will not be, so I’ll advise everyone to look around in the pits prior to the racing/ practice and identify those without! A twin has no issues because losing or sticking one cylinder doesn’t result in a locked up rear axle. And guys, never,never,never come up on the 125 guys or a 250 single without full knowledge they may lock up at any moment.