What Are Bias Tires? (Meaning, What Are They Used For + More)

Bias tires are one of three popular tire designs when grouped by ply construction.

This piece informs more on bias tires while identifying how they differ from their closest counterpart, radial tires.

What Are Bias Tires?

A bias ply tire is one whose plies lay in a crisscross pattern as they overlap each other. So, if you could see through them, one-ply will lay in one diagonal (between 30 and 40 degrees from the direction of travel), while the other will lay in the other direction, forming an “X.”

For more information on the uses of bias-ply tires, merits and demerits of both radial and bias tires, and differences between radial and bias tires, keep on reading!

What Does Bias Mean For Tires?

This means that when constructing a bias-ply tire, strengthening codes are arranged diagonally across the tire (usually 30° to 40° away from the travel direction).

Its cords are set at an opposing angle on each additional layer. A crisscross pattern is created as a result of this. To complete the tread, additional rubber is put over the plies.

Most bias-ply tires are four plies, which means they feature four layers of fabric cords for reinforcement.

What Are Bias Tires Used For?

What Are Bias Tires Used For?

Bias ply tires are becoming increasingly outdated as tire technology evolves and advances.

However, the design may still be put to good use: drag racing tires of a large size (slicks), off-road tires that are somewhat large, tires from a trailer, a few pieces of agriculture, and construction machinery.

Most classic car owners will only utilize bias tires because they want to maintain authenticity as much as possible.

Bias tires are available from specialized manufacturers for a range of antique automobiles, allowing these vehicles to keep their historical character.

What Is The Difference Between Bias And Radial Tires?

Bias tires are created by criss-crossing polyester and nylon belt cords at a 30 to 45-degree angle to the centerline of the tread.

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On the other hand, radials are built with crisscrossing steel belts beneath the tread to boost structural stability.

Their belt structures are the major distinction between radial and bias-ply tires; radial tires have steel belts while bias tires have nylon belts, resulting in different functional performance.

Which Is Better Radial Or Bias Tires?

Having tackled the basic understanding of bias and radial construction, let’s examine situations where each tire type has an advantage.

Radial tires have improved comfort. Radial tire technology has reduced the impact of nearly every road bump you’ve ever encountered.

Because the plies do not stretch across and down the whole tire, the tire sidewall is free to bend and absorb impact without transmitting it to the tire’s whole (interconnected) structure.

Radial tires have better heat management and dissipation. Because of its excellent heat management, the radial tire extends the life of the tire tread.

Tires generate heat while under load or in operation, and greater heat equals more tread wear, as in the case of a bias-ply tire.

Bias-ply has its own advantages, including their tire construction being less difficult, resulting in a reduced cost.

In some situations, such as trailer tires, where a bias-ply tire may give less wobble and bounce than a radial tire, the stronger sidewall might be advantageous.

Puncture resistance on the sidewalls and a tough construction (some agricultural tires are bias-ply)

Bias-ply tires for vehicles, on the other hand, have generally been confined to antique car/truck restoration projects and car exhibitions in recent years. If you want to get a real old look, bias-ply tires are the finest option.

On the other hand, radial tires are almost certainly the way to go for your vehicle because there are only a few current bias ply truck tire producers, but radial alternatives will nearly always provide you an edge no matter where or how you travel.

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Radial tires dominate every major truck tire category, including mud-terrain, all-terrain, and all-season by sheer presence alone.

What Is A Major Disadvantage Of A Bias Ply Tire?

What Is A Major Disadvantage Of A Bias Ply Tire?

Apart from availability, a major limitation of a bias-ply tire is faster wearing out due to increased traction.

Are Bias Tires Tubeless?

Bias Tires are not tubeless; they’re made up of a rubber-fabric casing and an air-tight inner tube.

Their inner tube is inflated to a specified pressure when it is in use. A bias-ply tire’s sidewall has a symmetrical structure made up of an even number of crossing plies.

Are Bias Or Radial Ply Tires Better For Trailers?

If you’ve been using bias tires for years because of their load capacity and you want to keep this up, ST radial tires could be worth a look.

Radial tires, on the other hand, have been known to perform better than bias-ply tires, and the difference is readily apparent.

They ride more comfortably, the trailer bounces and sways less and they last longer.

Their ability to bear a big load is the most crucial feature of any trailer tire. Bias tires were once thought to be capable of carrying larger weights than radial tires. That is no longer the case.

Radial trailer tires are now labeled with the “ST” abbreviation, which stands for Special Trailer, and are designed to bear big loads.

Are Bias Ply Tires Street Legal?

Are Bias Ply Tires Street Legal?

For regular street use, radial tires outsell bias plies. However, bias-ply tires are the most common tires on most racing cars at your local drag strip.

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A bias-ply tire’s structure allows the sidewall to wrinkle, which helps absorb the launch’s shock.

Nylon threads are crisscrossed in a crisscross pattern through the sidewall of bias-ply tires.

This design is sturdy enough to provide a safe tire while still being flexible enough to allow the tire to buckle during launch.

This characteristic makes them poor for cornering, as the flex might cause the tire to roll under the wheel in severe circumstances.

Do Bias Ply Tires Have Steel Belts?

As stated above, bias ply tires are made using two or more layers of nylon cords woven at 30-38 degree angles from bead to bead to produce the support and carcass (the network of cords that provides the tire its strength).

To guarantee stability, layers must be an even number.

Steel belted bias employs two or more layers of nylon cord underneath the tread and two steel belt layers.

This design results in a stronger carcass (the network of cords that gives the tire its strength) that provides greater support and a more stiff inner material to interface with the tread.

To know more about tires, you can also see our posts on what are non-directional tires, what are V-rated tires, and what are Z-rated tires.


Bias ply tires are becoming increasingly obsolete as tire technology evolves and advances. Radial tires are now the most common type of tires.

One significant drawback to bias tires is faster wear because of increased traction.

Bias tires are only suitable for the race track being used efficiently by drag racers.

While bias tires have been used in trailers due to their higher load capacity, the introduction of ST radial tires has displaced them from this role.

Bias tires have belts made out of nylon.

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