In CMX there is no "Open" capacity class. The term "All Powers"
is used when all capacities are to run together.
The big bore class is "263cc+" so a 250 can't run in this class.
Yes there will be rider age specific classes in each capacity in Pre75, plus open rider age classes in each capacity of Pre75.
Note:- as stated in Sup-regs 40 max starters in any class, so get those entries in early ( same as Crystal Brook )