More PSI = Better Tire life?

[Satchel]

I've been told by a few people .. if you run more PSI in your tires (35-40) (Cold) on the street, you will effectively get more life out of them... at the loss of a small amount of grip/traction

Does anyone know the science behind this? Why would putting more PSI in a tire, increasing the size/carcass give you more tread life?

Just curious .. :squid:

[mieff]

well, first off there is less of a contact patch. less contact with the road, less wear on the tire. and, since there is less of a contact patch there is less friction, which means the tire doesn't get as hot. the hotter the tire gets the quicker it wears down. i'm sure someone else may have a more scientific and more detailed explanation but that is how i understand it. :squid:

[TreAdidas]

I'm guessing here but....

The lower the psi of the tire, the more friction in the carcas. More friciton in the carcas heats the tire up and that makes the tread softer and grippier. The problem is soft and grippy rubber wears quicker than hard and no so grippy rubber. In theory wouldn't having a higher psi make teh carcas harder resulting in a lower amount of friction in the carcas, therefore not creating high temperatures, thereby leaving the tread relatively cool and harder, thus providing more treadlife? I say yes.

[mr01000101]

Chuckie and Mieff have it. The weight of the bike presses the tire against the road, creating a little flat spot at the road-tire interface (aka contact patch). As the tire rolls, the contact patch is moving along the diameter of the tire. As a particular spot on the outside of the tire moves into the contact region, the tire is bent from its normal curved shape to flat, and then back to curved again as that spot passes by the contact area. This quick flexing/unflexing of the tire generates heat. Now, a higher tire pressure will result in a smaller contact patch, and as a result the tire won't have to flex as much as it did with the lower air pressure. Less flex equals less tire heating. Lastly, rubber softens as it warms, so the scrubbing forces/stresses on the tire will wear a warm tire faster than it will a cool one.

[bdmmotard]

Well yes the tire will last longer, but it's kinda defeats the purpose. the reason to have your tires last is for traction, and if you have high tire pressue you'll have minimum traction. Think about the cost of 1 crash vs the cost of a set of tires. esp if you get hurt. In the long run, lower pressure is cheaper.

[wanderer]

Well yes the tire will last longer, but it's kinda defeats the purpose. the reason to have your tires last is for traction, and if you have high tire pressue you'll have minimum traction. Think about the cost of 1 crash vs the cost of a set of tires. esp if you get hurt. In the long run, lower pressure is cheaper.


higher air pressure doesn't affect contact patch as much as you think it does. tiny increments of an inch and the bike will turn in better

for everday riding i highly recommend bumped up air pressure. for "spirited" rides, most people would probably find absolutely no difference in handling.