Specialized Turbo Como 3.0 Frame Adapter

[Projectman]

I purchased a Thule Frame Adapter/Bicycle Cross Bar so I could mount my Turbo Como 3.0 on my bike rack. The opening was too small to go around the head post. Anybody purchased a frame adapter that will fit around the head post? Also, the frame adapter was rated for 50#. Need something with a little more carrying capacity.