Originally Posted by godspiral
1. Can you explain how a squared off tire is different than having less air pressure in your tire?
2. doesn't the rear tire have a higher chance of skidding out in a turn (or is that just if there is sand/gravel)?
1. Contact patch is determined by a combination of tire shape, pressure and rider weight.
Imagine a tire that is presurized high enough to "not deform" under a static rider load. Now image a squared off tire in that situation. The entire width of the squared section of the tread is in contact with the road. If it is a round tire (remember that the pressure is high enough in this example to prevent deformation under rider load) the contact patch will be smaller.
Think of Area Moment of Inertia and the difference between an I-Beam and a flat bar wiehgt bearing capability differences when thinking of the impact of shape on loading....
As the pressure decreases in this example from the "max theoretical" in my example to a real world riding pressure...the tire will deform, but think....botht the rounded and the squared will deform at the same rate if pressures and weight are held constant. Net result is a larger contact patch in with the squared tire.
That being said...the differences have got to be so small that they are not only non-noticeable by the rider, but negligible. I mean we're talking about small area differences in mm2 with large weight. It's like talking about how landing a fly on an aircraft car will change the vessel's handling.
So to answer your question it is possible to acquire the same increase in contact patch by either having a squared tire, or by decreasing the pressure in a rounded tire...they aren't different...in a straight line. I don't wish to begin to tackle cornering.
2. I agree with what has been written about this one. I find the rear skids more, probably due to the higher lateral forces a tire sees in the rear while conering due to the higher percentage of rider weight it is bearing.