I just picked up what looks like a never used(NOS?) sew-up wheel and tire with a Sugino Tension Disc installed. The valve stem is accessed through a small hole in the disc. The hole is too small for my pump chuck to fit through. I,ve tried to thread on a stem extender but still not enough room. What's the secret of inflating the tire? How does one remove the Tension Disc from the wheel without destroying it? Thanks RGH