tires, tube valve stem

[Ben Ransom]

Today I put a tube on a standard 6" MAM wheel without the tire and noticed that the ID of the tube is at least 1 inch bigger than the OD of the wheel, with air pumped in, or not. Maybe this is unimportant, because the tube will fill all the space with the tire on. But I'm wondering if this could lead to the tire working the tube around to the point of breaking off the valve stem