The two people who continue to insult and malign me, and their personal attacks, are demonstrating their lack of tolerance for differing views which are solidly-supported by the tire manufacturers and the motorcycle manufacturers. Why is engineering a bad thing? Why do you feel a need to personalize the attack on someone expressing their support for the prevailing engineering research on using something not-designed for your choice of your individual use? If you want-to use a car tire, and you do, that's on you. If something happens because of that behavior, that too, is on-you.
Compare it to using a hot load in a handgun where the frame and construction isn't designed to withstand the pressures generated by the use of the propellant in the hot load. Maybe you are able to use it X number of times, until the metallurgy and design of the gun fails to withstand the loads to-which it's repeatedly been subjected-to by your use of powder beyond the parameters of design the gun manufacturer used. It explodes, maybe you lose your eye(s) because of the shrapnel. Maybe you're lucky-enough to just have to take a trip to the E.R. to have the embedded hot metal removed from your epidermis, and debridement of the charred skin from the flash-burns you sustained. Hopefully, no one else was victim to your catastrophically-failing firearm and your negligent use of it.
Radial tires are designed for a different bead size, the width of the tire and the spread of the carcass on the rim to-which it's mounted. Our rims aren't designed to allow a radial tire to sit properly upon it/them. Squeezing a tire designed for a certain minimum mounted width onto a narrower rim will cause the tire to adopt a profile which causes the surface contact area to be less than the tire engineers designed it to do. It will also cause the construction of the tire to not function as it was designed to, resulting in the plies moving against each other in a fashion for-which they were not designed. This causes excess heat, flexing of the tire carcass in a fashion for-which it wasn't designed, and an inability to function for traction and longevity according to the design parameters of a team of engineers. But hey, if your youtube video you found says "lookit what i did!" and you're OK with that, go for it!
The materials in tires are carefully-determined for durability (that would be wear), performance (stickiness), and cost. In your instance it seems saving a few dollars takes precedence over every other design parameter. We all have values, and yours are obviously on the side of sheckel-saving. When a tire manufacturer tasks its design team with construction of a new tire, they have product goals, and price is one of them. The mass market would be very-small for a $800 single tire, even-if it was superior in roadholding grip to everything-else in the same size, unless it's to be installed on a MotoGP racebike or some-other narrowly-defined use where grip and the ability to last for an entire MotoGP race while still providing predictable handling is the #1 consideration. The friction modifiers and the amount of lampblack included in the design are just one-part of the equation. The carcass construction is another. Tires designed to withstand huge rotational forces like a land-speed record tire (where growth in diameter and longevity during use) are much-different from a road-racing tire where cornering and the ability to provide consistent feel while used over the duration of the race are much-different. Tires are designed so they heat-up to a point where the rubber compounds activate to provide the type of performance designed into-them. If that heat range is exceeded or if it isn't reached, then the compound won't perform at its engineered operational point of use. Similarly, motorcycle manufacturers work with the tire manufacturers to develop tire designs complimentary to their motorcycles. In the "good old days," it was common for bigger-engined motorcycles to run a bias-ply 19" tire with a narrow width (designed for a WM-2 1.85" rim), compared to today's bikes' widths (set-aside the radial construction often used today for the moment). When the 16" tires for mid-1980's sportbikes came-out they steered much-quicker, and tire construction changed from what was used on the old 19" size. Thirty-two years ago, Yamaha released their big sportbikes (FZR750/FZR750R; FZR1000) with radial tires, and tire design in motorcycling entered another age. In some limited instances, manufacturers have even mixed radial and bias-ply tires, Harley-Davidson did that. The same way tire manufacturers warn-against car tires on motorcycles, they also warn-against mixing different designs of tires, i.e., radial and bias-ply,
unless the motorcycle manufacturer specifically designed the motorcycle in that fashion. Even-then, differences in design of radial tires means that you need to pay attention to the construction to prevent you from mixing incompatible designs. Some radial tires have an oblique angle between successive layers of cords, while others use a "zero-angle," where the successive layers are at right-angles to each other. This affects the way the tire flexes in-use. Using an oblique-angle radial tire with a "zero-angle" radial tire will make you the very unhappy rider of a motorcycle which has weird and unsafe handling. There's much-more to choosing a particular tire than to base your choice solely upon pricing.
The two champions of car tires on motorcycles aren't going to care about the engineering of motorcycle tires, they have already voted with their pocketbooks that price is their overriding concern. This information is directed to the rider who may be considering trying a car tire on their motorcycle but who hasn't been exposed to information from the motorcycle manufacturer or from the tire manufacturers.
Something that makes me curious,
cwkerr007 talks about bygones being bygones, yet reverts to insults, including remarks about my family. As I mentioned, the best predictor of future behavior is past behavior. Have you no shame? Do what you say, agree to disagree, and stop your personal assault.
Your report on the
mich tires (radials) (sic) you posted-about, I think you aren't aware that
mich (radials) (sic) isn't the only manufacturer of 15" radials that will fit onto a 15" motorcycle rim. I submit proof from my personal inventory of new tires (attach.) This tire is designed with an H speed rating, while the VMax was designed to require a V speed rating. The difference is 130 mph vs. 149 mph (H to V ratings). If you don't run your bike over 130 mph, the Bridgestone radial may meet your needs but if you do then out of consideration for your personal safety, use of a V-rated tire will be the tire designed to allow safe operation, closed-course use only, of course. You also need to consider that the Bridgestone 15" tire is designed for a 5 inch rim where the VMax rear rim is much-narrower.
https://www.bridgestone.com/products/motorcycle_tires/products/battlax/th01.html
This will pinch the tire carcass inwards distorting the designed footprint, something that an unsuspecting user should know, hopefully before purchase.
Another consideration about the radial tire is the aspect ratio of radials used in motorcycle tires is a much-lower number than that of the OEM VMax bias-ply tires. What this means is that the measured tire height will be much-less, effectively resulting in a 'lower gear ratio' compared to a stock bias-ply VMax rear tire. How-much of a difference? My measurement of a new Shinko bias-ply tire sized to a VMax rim is 25" where the Bridgestone pictured in the attachment is only 22.5" Effectively, that's a 10% difference in height, meaning your rpm's will be that-much higher, and with a corresponding lowering of your fuel economy and your top-speed. People who use 17" radial tires on aftermarket wheels or modded wheels (which I have supplied to members) are fully-aware of this. As-mentioned, it does lower the stance of the bike, and if you're "vertically-challenged," this may allow being able to put both feet flat on the pavement at a stop. For someone like a petite woman, this may allow them to ride a VMax where in the stock 90-series 150 x 15" tire would have her on her toes at a stop, not a secure feeling when trying to support a 600 lb motorcycle on a crowned roadway, at an intersection where cars and trucks have deposited oil, coolant, transmission fluid, grease, construction debris, hot tar, and whatever-else finds its way onto the roads. Then, add a recent rainfall to make a slippery soup of all of this, and you can understand why for some, lowering the bike via a tire/wheel change is a very practical thing to do.
How-long until the next personal assault? I suspect we won't have long to-wait. The popcorn's popping, now.