The article by Calvin Hulburt, a self-described retired engineer, gets off to a seemingly good start, and even refers to some of the other bad bicycle science already published elsewhere. It does get into a little trouble early when it dismisses the two-mass skate bike, by Kooijman et al. as a mere gadget, but recovers by citing Lowell and McKell and then Wilson-Jones.
After that, however, Mr. Hulburt really heads into the weeds. His attribution of bike stability to tire forces may sound reasonable to the uninformed, as did Sokal’s paper, but his argument includes no calculations, no supporting evidence, and makes no testable predictions.
This is not Mr. Hulburt’s only attempt to get his “theory” accepted. Besides several youtube videos, and several insertions into the wikipedia article, he recently began a discussion on the Single Track Vehicle Google Group. There, various members pleaded with him to make a testable prediction, but Mr. Hulburt declined, and replied instead with a parting dig about the two-mass skate bike paper.
That was met appropriately with a resounding chorus of silence by the rest of the group.
Probably the best comment before the end was from Andy Ruina, a professor in the Mechanical Engineering Department at Cornell University, who tried to prod Mr. Hurlburt into stating something useful with I don’t want to dismiss you, as you have great intuitions and energy. But do you know the line: “Not even wrong“?