There are two different tires; radial and bias-ply, the difference is in their construction. Radial tires give better service than bias-ply tires as they wear better and handle better due to the improved flexibility of the tire sidewall. Michelin tires in Charlotte contain steel strands which run around the circumference of the tire, this helps stabilize it.
From the surface a tire looks like a pretty simple thing but actually they are made from layers of various materials. If it was possible to peel back the tread from a bias-ply tire, which of course it isn’t, you would find nylon plies underneath, these ply’s run diagonally and meet at the centerline of the tire face. The weave continues over the face of the tire and angle down the sidewall ending at the tire bead, the bead is that part of the tire which fits on the vehicle wheel. Although nylon is stronger than polyester it tends to set under a load, this is especially true if the vehicle sits motionless for an extended period of time, the result is a flat area on the tire tread. The sidewalls of a bias-ply tire do not bulge even if the tire pressure is low.
Radial Michelin tires in Charlotte are manufactured completely different. A radial tire does not have nylon plies meeting at the tire centerline, it is constructed using polyester cords that run from tire bead to tire bead, perpendicular up over the tire and down the opposite sidewall.
On the face of the tire, the tread area, running over the polyester wrap is a belt running under the tread. The belt is almost the full width of the tire tread and runs circumferentially, the tire takes on a rather square look. In the early days of radial tire manufacturing the belts were made from fiber that was rubber coated, today almost every manufacturer uses steel fibers; this is what lies behind the term “steel belted radials.” The belt helps to reduce wear by stabilizing the tread; due to the tire construction the side wall will always bulge out at the point where it makes contact with the road; although they may appear underinflated, they are not when at the right pressure.
One can expect radial Michelin tires is Charlotte to give about 100,000 miles before replacement, a bias-ply tire will generally give about 30,000 miles of wear. Although radial tires are more expensive than bias-ply tires they are better value as they do not cost three times as much, which is about the extra life one can expect.
