Igor, our warehouse manager, wanted a top tube protector for a different reason. He wanted to protect his paint when he leaned his bike against a parking meter or street sign. But he didn't like the BMX-style top tube pads sometimes used for this purpose. So Igor made the protector below out of the elk hide that we use for bar covers.
I think it's a pretty good idea. It would work even better on a bike with a run of cable, rather than cable housing because it would fit under the wire better. Or you could sew it over the housing. In any case, do you think this is something we should make?