I guess not checking led to loosing the seal, first one side early May, the other last week. It is just a bit difficult to air up because the valves are on the inside. Is this normal? Of course I could take the wheels off and swap sides, once I get air back in. And the 'V" tread pattern, what direction should that face, the base of the "V" forward or not? Does it really matter? Just the valves are causing me to swear....a bit