Post by
AmoebAssassin »
https://forums.nicoclub.com/amoebassassin-u22213.html
Sun Jun 24, 2007 6:30 pm
"No competitive motorsport uses stretched tires" is a VAST blanket statement and not at all correct.
To understand why or why not certain motorsports see use of stretched tires, you must understand the type of tire being used and the properties of each given tire.
Many "slick" racing tires you see today are super soft compound, bias-ply tires. Bias ply tires generate more lateral (cornering) force at higher slip angles (slip angle is the angular difference between the plane of rotation of the tire, and the direction the tire's contact patch is pointing in) than they do at lower slip angles; having an unstretched, or even bulging sidewall reduces a property called "cornering stiffness," which describes the ability of the tire to generate slip angle for a given inflation pressure and normal (vertical) load. Therefore, if using a bias-ply slick tire, it is advantageous to run tall, bulging sidewalls as it puts you in a position to generate lots of slip angle, and therefore lots of corning force with that specific tire.
Radial tires, on the other hand, generate more cornering force at lower slip angles than they do at higher slip angles, where they tend to "wash out" and slide. Thus, when using a radial tire, it is best to run a lower profile, slightly stretched fit tire. Stretching the sidewall increases the cornering stiffness of the tire, keeping the tire at lower slip angles, and therefore creating more cornering force from the radial tire and preventing tire washout.
Stretching is also an advantage on some street tires (which are predominantly radial construction), as stretching tires reduces sidewall rollunder during heavy cornering and creates a more predictable breakaway feel in the car.
Therefore, while one race car may have a fat, bulging fit bias-ply tire, another race car can be equally as fast with a slightly stretched radial tire.
On topic though, i think the fitment of those tires looks f'in badass Grant. Everyone has their own sense of style when it comes to wheels and tires -- I tend to agree with your selection. It just looks super aggressive to me.
-Neel