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Discussion Starter #1
As I understand it, grip from a tire occurs when a tire is heated to the appropriate range and tiny pieces of the tire slough off on contact with the road. Assuming this to be accurate, what should be the effect on grip and wear when the tire never warms up enough to reach operating temperature?



Trying to figure out a reason for quicker tire wear under cool operating conditions: less than 60 degrees F ambient air temp. Also wondering what effect tire pressure has on this, knowing that higher air pressure leads to cooler operating temperature of the tire.


Any thoughts?
 

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This is far and away not a simple question. The particular tire compound has a big effect on wear and temperature effects on wear.

Air temperature has some effect on tire wear because, in general, if the air is hotter the road surface is hotter and the tire surface is hotter. Hotter tire surfaces can wear a bit faster because that is how tire compounds behave.

There is a phenomenon where elastomers wear faster when they are cooler. I don't know how this would affect motorcycle tire rubber, but if you want to, for example, change the tread depth of an auto tire (where you need to remove a lot of rubber) it helps a lot if they are cooled off, say in an old chest-type freezer. The belt sander tends to cut faster, not get gummed up with soft rubber.

Higher air pressure does cause tires to heat up more slowly than lower pressures, and generally the highest temperature reached will be lower, too. This is mostly because of reduced tire sidewall and tread flexing. It also changes the contact patch profile and "squirm". The contact patch doesn't reach and leave the road surface cleanly. Areas of the patch, particularly the edges, slide a bit both in contacting and in leaving the road. So the whole patch moves a bit, which is called "squirming". Higher pressures generally reduce the area of the patch, so the load at any point on the patch may be higher.

Too low a pressure can cause the contact patch to squirm a lot, which will increase wear.

It's not necessary for bits of the tire to scrub off to achieve traction. Traction is achieved by a combination of coefficient of friction between the tire and the surface, and the "bumpiness" of the road texture. The road texture pushes into the surface of the tire providing mechanical grip.
 

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my experience is the cooler it is, the longer tires last

the Pirelli MTR60-corsas that I run in winter wear out in 1000-1500 miles in summer temps, in winter, I get 3500-4000 miles running lower pressure to make them warm up faster on frozen pavement
 

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Discussion Starter #4
Thanks Andy and Randy; I was hoping the two of you would chime in.


I can't figure it out, but I'm absolutely skewering the set of Road Attacks I'm on as far as mileage goes; same thing happened with my (previous) set of BT021's. Both have/had seen a large proportion of miles under cool conditions, and both are reaching substantially lower mileage life than expected. Both have 'softer' rubber compounds than other ST tires I had used previously.


Wondering if I inadvertently helped speed up wear on the tires by keeping them inflated high (39-42 rear psi) thinking I would prolong tire life. While theoretically this should work during hot summer months, is it possible the high inflation worked against me in the cooler fall and spring months?

Or is simply a matter of the rider being (overly) cautious during cooler months given that traction is reduced, leading to many more miles riding straight upright down the narrow middle of the tire?
 

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You didnt mention tire type, brand.
That would help since some tires wear out quite quick compared to others.

Ok so you did mention tires... I was just a minute late with this post
 
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