This is one of my secret glaring errors. The valve stem arrangement is correct for a pre-'98 Basset wheel, but not for these Aero wheels. I didn't notice the change until long after I built the model. On the aero wheels, the valve stem for the inner liner should be on the other side of the spokes, just visible through one of the holes. Don't paint the insides of the wheels body color (as I did), either; they're actually the color of DuPont VariPrime on the inside on most cars. Some short track cars have some kind of metal taped to the insides, too, I guess to provide a little insulation from the searing short-track heat from the brakes.