Bikers who see bias-ply tires listed in their OEM bike parts may wonder why they don’t have the newer radial design. The proliferation of radial tires on high-performance machines seems to suggest they’rethe best motorcycle tires. They replaced bias-ply on many motorcycles in the 1980s and you don’t see a bike without radials on the racetrack. How are the two types of tires different and why have bias-ply remained on dirt bikes, cruisers, and touring bikes? The reasons lay in how they’re made and the benefits of their designs.
What Is the Difference Between a Bias-Ply Tire and a Radial Tire?
The two kinds of tires are separated entirely by the methods of construction. The bias-play variety is constructed with polyester, nylon, or rayon body cords that run across the entire width from sidewall to sidewall in alternating layers. The radial type has body cords made from steel and run across the radius of the tire from bead to bead. Radial tires also use the bias-ply system, but only for the tread portions.
What Are the Advantages of Each Types of Tires?
As a more effective conductor of heat, the steel body cords of a radial tire transfer heat more effectively. Fast riding creates a lot of heat, which can cause issues on bias-ply tires. The radial layers aren’t as thick as the bias-ply, allowing for thinner, more flexible sidewalls. This keeps more of the contact patch on the riding surface and provides better feedback to the rider. The stiffness of the bias-ply tire doesn’t allow for as much independence between the sidewall and tread.
Also Read: How To Change Motorcycle Tires
On the other hand, the thicker layers of bias-ply system make for a stronger tire. Radial tires don’t allow for innertubes, meaning that all spoked, tubed tires are bias-ply.It should also be said that while there are some cheap motorcycle tires of each variety, neither is considered to be low quality by manufacturers.
Why Aren’t All Tires Radial?
If you read between the lines on the benefits of each design, you can tell where it shines. A tire that’s great for speed and cornering? Radial tires have sportbike written all over them. The thinner layers also allow for a wider wheel without enormous sidewalls. If you want afat tire on your rear wheel, it has to be radial.
The added strength of bias-ply tires is excellent for loaded down machines such as heavy cruisers and touring bikes. These motorcycles aren’t typically designed for the speed of your average sportbike, so the lack of heat dissipation is less important. A classic cruiser with spoked wheels needs the bias-ply for its vintage look. Because spoked wheels are also stronger, dirt bikes are fitted with bias-ply tires to withstand the greater stresses of off-road riding.
Which Ones Should You Buy?
For bikers, it’s rarely a question of which is the best, and more a question of which is best for you. Both types of tires are used by your favorite manufacturers because they both have their purposes. There’s no reason to limit yourself if you enjoy multiple riding styles. Install a set of bias-ply or radial tires and enjoy your ride.