Originally Posted by andrewclaus

The QR system is not load bearing in the shear direction. It's a tension device only. It clamps a hollow, shorter axle to the frame dropouts. The ends of the axle do not extend past the outside of the frame. So you can't use it for a solid axle, but one could fabricate similar adapters. As mentioned above, P-clamps are much easier if you can make the upper hardware work. Often that needs to be modified anyway.