Road & Track article - take #2

Hmmm... Changing an original message apparently changes it when the message gets moved as well. I'll need to remember that

Anyway, a friend posted a link on another site.
http://www.roadandtrack.com/voices/why-so-called-darksiders-prefer-auto-tires-on-their-motorcycles

Since the message move etc, I don't remember all that I commented on but the main point was that even though there are so called incompatibilities with car tires on bike rims, they still work and work well and safe enough. As the article mentions, that may be because car tires are so much better, they have performance in reserve that allows them to work well on bikes. I agree.

And there have not been many improvements to bike tires in a long while. Things like dual compound in the tires in efforts to increase bike tire longevity only help marginally and are currently only on limited sizes/styles of bike tires. Still, they won't attain the longevity of car tires. That fact is inherent in their design.

Car tires last longer because they have and use the full width of the tread available to share load and wear along with their superior compounds. Whereas bike tires have harder compounds that wear faster because of the tread layout and how that tread is used. Most bikes spend most of their time upright and only about 1/4 to 1/3 of the bike tread is available at any one time because that tread is laid out in an arc. Only part of that arc of tread can be on the ground at any one time to take load and wear. It is no wonder then that the center section of tread wears out first on bike tires.

bandito2 quote
"Whereas bike tires have harder compounds that wear faster"

Bike tires have softer compounds so they stick to the road better and the softer the rubber the faster it will wear. I don't want to offend you by saying the opposite of what you said but misinformation does no one any good. The dual compound tires are harder in the center for longer wear and softer on the edges for better grip when you lean into the curves.

model28a wrote:

bandito2 quote
"Whereas bike tires have harder compounds that wear faster"

Bike tires have softer compounds so they stick to the road better and the softer the rubber the faster it will wear. I don't want to offend you by saying the opposite of what you said but misinformation does no one any good. The dual compound tires are harder in the center for longer wear and softer on the edges for better grip when you lean into the curves.

Yes, sure I know about the dual compound tires, I inferred that much in my post, but they still wear faster.

Very well then, but don't be offended when I tell you that you are wrong about the rubber compound of bike tires being softer than car tires..... it is not.
Passenger vehicle tire (car tire)  compound IS softer than the rubber compounds used for bike tires. It is a common misconception.
However, bike racing tires can reach the Durometer number (a measure of material hardness/softness) of car tires. But mostly, standard street tires for bikes do not. And I believe in the main, we are talking about the bike tires commonly used for the street here; not racing tires.

In fact, I have a simple test you can perform yourself to prove my point that car tire rubber compound is typically softer than MC tire compound. Anybody else may also try it too to see for themselves.

Take a ball point pen and carefully balance a weight (I used a MC battery) on top with the nib pointed directly down onto the tread of a car tire. Notice how far into the rubber it presses. Now do the same thing onto a motorcycle rear street tire and also note those results. Typically, the nib will sink further into the car tire rubber than the motorcycle tire rubber. Use a lighter weight for testing both tires if it presses too far in to be able to tell and use a magnifying glass to be able to see better if need be. And don't bounce the weight onto it, gently ease it on the same way on both types of tires for consistency in testing.

To be fair, note that I say typically. That is because there may be instances where the difference is too difficult to detect using this method and because some tire compounds will differ by only a few points. But, by and large, most of the results should confirm that car tires have softer rubber than motorcycle rear tires.

This simple test is essentially what a Durometer (a device for measuring hardness/softness of materials) does. While not as accurate as a Durometer, it should do well enough to confirm my statement that car tire rubber IS typically softer than the rubber on a standard motorcycle rear tire. Go ahead and try it; anybody, for or against car tire use... even those just curious to see what happens.

Indeed, misinformation does no one any good, and good information enlightens.
Click the link below, scroll way down and read the last paragraph of the first quite extensive and well researched post. (and be informed and enlightened)

Car tire compound IS softer & stickier than bike tire compound and lasts longer for reasons as I have stated before; car tires last longer in spite of having softer, stickier rubber compound because the whole width of the tire tread is used and distributes the load and wear. I've been around this car tire VS motorcycle tire debate for quite a while and have done quite a bit of research as well. So I do know that of which I speak.

http://www.goldwingfacts.com/forums/10-reference-faq-forum/400426-design-differences-between-car-motorcycle-rim-tire.html
Hope this clarifies the differences in tire compounds for the readers here.

You might eventually like to read that whole post... It is very long, but informative, points out things you may not have known and dispels some myths and misconceptions about both car and bike tires.

There are other extensive articles that cover and confirm this same information, but this is the one that I could find close at hand.

As to other aspects in the above article and others, I'll ad-lib a post somebody else there posted about car tire VS motorcycle tire articles.
The technical design information in those articles on the differences between car and bike tires is extensive, but not a bit of dynamic application information is presented. That is; no real life information on what actually is going on with car tire use on motorcycles. I acknowledge the design differences between them and understand that each tire and rim was designed with a purpose in mind. However, the historical application data suggests these differences are irrelevant. In spite of the design differences, it has undeniably been demonstrated that car tires will work successfully on motorcycle rims. There is not data presented to suggest otherwise. I will live with the "theoretical" risk of the car tire on a motorcycle (or scooter) type rim, rather than the higher "demonstrated" risk of the motorcycle tire.

(as long as I'm being informative, I might as well do it in spades eh?)

Well as informative as that was researchers seem to forget that 2 track vehicles turn by countersteering and leaning. Ain't no way no how a car tire with a square edge is going to allow a rider to handle a bike better for it's design. I value staying upright more than tire life. To read a car tire lasts better than a bike tire is misleading at best. There are ratings on tires as to treadwear and traction on car tires and they vary widely. I would consider a car tire on the front of my trike or maybe a sidecar rig. No thank you on my 2 wheelers. Good to know on a road trip, but in today's world of internet a proper tire could likely be had in a day or two.