Henro, That's how I filled mine....but whenever I try to check the air pressure of tire (having valve stem at 12:00 again) I get nothing but water out of the stem? Ruined a gauge or two before I realized it. Still at 12:00 and try to release air to clear out water and no luck, Only air/water continues to come out valve stem. Does water expand? I'm sure I stopped filling once the water reached the valve stem and began to come out. I figured that would give me about a 25% area for air and 75% weight to tire. But I never truly know how much air is in the tires as I cannot check them. Should only need 10 or 12 lbs but would be nice to be able to check without draining water back out. Am I missing something here? Thanks, Greg