hey, iam going to buy new front and rear tires becuase mine are shot already, i race motorcross and want 18 on the rear and 20 in the front that iam sure of, but i dont know which tires to get, i would like a some what reilable tire but for mx i see that not happening, i race mustly on suft, loomy dirt, but every once in awhile iam on hard pack, thanks for any edvice,