Stan's ZTR rims, loose fitting tires

hey

i have the ZTR freeride rims. when i first tried to mount tires on, tires fit super loose. you didn't need tire levers at all. i used tubes at first. while in flating i had to make sure the bead was staying in the hook. once inflated it seemed fine. i've had them since about early july, with no problems. i finally started running them tubeless with sealant 2 months ago. again had no problems running standard tires tubeless. worked great. then i punctured the side wall and used tubes for the next couple rides.

this last weekend i was going down a rocky trail. i had pretty good speed, but at least it was straight. i pinched flatted and the tire came completely off the rear rim. i probably rode on the rim for a good 10 yards or so before i could stop. i'm just glad it was a straight section of the trail. so theres several small dings in the rim. so far it still works with tubes haven't tried going tubeless yet. do the stan's olympic rims fit tires loosely too? anyone else have the freeride rims?