palerider
Well-known member
Good point. Also the patch will vary between tires of the same size but from different manufacturers and even from the same manufacturer within different models of the same size. The PR4s contact patch will be different from the PR3 and so on. Every tire is going to have slightly different ride characteristics.From what I recall, the contact patch size (total area) is not affected much, if at all, by the profile of the tire.
The shape of the patch will certainly vary, but the size of the patch is entirely dependent on the amount that the rounded tire deflects, which is more related to the weight of the machine and the pressure in the tire. When a lower profile allows a wider patch, the weight being supported by a wider area of tire will deflect the tire less producing a shorter patch. And vice versa.
Now the shape of the tire might bias the various performance characteristics of the tire differently; for instance, the lateral adhesion (for cornering) vs. longitudinal traction for acceleration and braking. Just something else to consider.
As sentient humans, we get to make choices. We listen to advice, weigh that advice, then decide for ourselves what is best for us. My 1984 V65 Magna was supposed to have bias ply tires on its cast wheels. Radial tires for motorcycles were not widely available in 1984, so naturally enough Honda never considered them that year. Years later, some gutsy member of the Magna forum had the courage to try a radial. It fit, and it transformed that bike, making it handle and ride 100% better. Did it have a different contact patch than the officially recommended bias ply? Uh huh. Would Honda and Allstate have approved? Certainly not. Might it have caused problems with insurance payouts? Maybe. Who knows? It would have been a battle of experts. My experts would have said the radials, even if not officially approved, actually made the bike safer. A jury would have decided.
But as someone who tries to be in control of my own life, I chose to run radials on the Magna. That's what freedom and liberty is all about. That's why I ride motorcycles. What's sad is the number of people who are so scared of the world that they abdicate their individual sovereinty over their lives and allow paragraphs in magazines to dictate their choices.