Radial tire are your regular tires, as it’s the new type of tire’s internal make-up which replaced bias-ply construction. With this, the tires now have better fuel efficiency, longer tread life and improved handling and ride comfort.
Radial tires are a more modern design that have been widely adopted. This is because they can flex more easily, which reduces rolling resistance and allows the tire to conform to the road surface better and they do it with better heat dissipation properties, which allows them to run cooler, reducing the risk of blowouts and increasing their lifespan.
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Bias Ply
Bias-ply, also known as Cross-ply tires have cords that run at an angle to the direction of travel, between 30 and 40 degrees.
These inner cords or plies, have a crisscross pattern, and they form an X shaped pattern, allowing a more rigid structure.
This design makes them less flexible and provides a rougher ride than radial tires. They also have a less efficient heat dissipation, which makes them more prone to overheating and blowouts.
Though, it’s worth noting that bias-ply tires are still used in some vehicles and equipment today, such as trailers, buses, and some heavy equipment. They are also used in some specialty applications where the more robust structure of bias-ply tires is desired, such as in off-road vehicles or aircraft.
Radial Tires
A radial tire is a type of tire in which the cord plies that make up the tire’s body are arranged at 90 degrees to the direction of travel, or “radially.”
These basically include multiple cords that are piled on one another. You have the polyester casing, having steel belts layers on top, which are then topped up by nylon based cap plies.
Only the polyester casing layer is underneath the sidewalls, whereas the central tread has the rest of the plies there.
So, you get a better combination of softness and hardness in the overall tire’s construction, allowing better grip, handling and at the same time comfort and heat dissipation.
Benefits of Bias Ply Tires
Like already mentioned bias ply tires are mostly used for commercial trucks and trailers, and not as common for passenger cars. And this is because of their following benefits.
Improved load-carrying capacity
Bias ply tires are constructed with layers of fabric that run diagonally across the tire, providing a more even distribution of weight. This design allows bias ply tires to carry heavier loads than radial tires of the same size, making them ideal for use on commercial trucks and trailers.
Since there are an equal number of plies to provide support to the weight of the vehicle in both the sidewall and the tread face, bias-ply tires are the best in handling heavy loads.
Better puncture resistance
Compared to Radial, bias ply tires have thicker construction, mostly on the sidewalls.
In radial construction, the sidewalls only have polyester casing protecting it from underneath, while the rest of the layers of steel belts and nylon on come under the central part of the tread. That’s why sidewalls are the weakest part of the tread here.
Whereas Bias Ply have thicker sidewalls, as they have the same number of plies underneath there, as the middle part. So you get better puncture resistance here on the most vulnerable part of the tread.
For Your Info: There’s a limit on how close to the sidewalls can tires be patched when it comes to radial tires, however, on bias ply tires you have a much better ease of repair. And so this also allows them to last longer that way.
Less Noisy
Noise generated by a tire depends on a variety of factors, most of it is from the air, and that air move around hitting the walls to create “tread noise”.
With a rigid overall construction, bias ply tires don’t allow a lot of air to come in. And the air particles which strike around the tread walls, don’t create as much resonance again because of the structural rigidity.
(I explained this in detail in, noise in all-terrain tires).
Affordable
Compared to radial, bias ply tires are generally less expensive. That’s because they a much simpler construction, allowing them to get manufactured easily.
Their inner construction also doesn’t include complex materials like the steel belts, polyester, polyamide and nylon. They are just made out out of a same fabric materiel throughout.
Moreover, these tires are also low in demand, as they don’t get to be as much popular.
And since they are mostly used in commercial trucks and trailers, they are typically purchased in large quantities. This allows manufacturers to sell them in bulk at a lower cost, making them more affordable for commercial use.
Benefits of Radial Tires
Now lets see what radial tires bring to the table.
Improved fuel efficiency
As already mentioned, the sidewalls of the radial tires don’t have as many layers underneath, it allows the tire to conform on the roads with more ease, whereas the middle part of the tread stays stiff.
This allows for a great combination of the flexibility and softness in the tread resulting in better fuel consumption.
So when driving under stress, the tire distributes the weight across different parts of the tread with more ease keeping rolling resistance lower (compared to bias ply tires).
Longer tread life
The lower rolling resistance values (discussed above), also account for longer tread life.
Tread wear basically depends on two main things, pressure distribution and heat.
The pressure distribution of the radial tire ensures the tread lugs don’t get to rub too much off the road, as they create a slightly bulge on the sidewalls, (as they are softer). So this way pressure is taken on the sidewalls and as a result the tread gets to wear slower.
Moreover, with superior pressure distribution efficacy, radial tires get to have a more even wear on all parts of the tread.
Related Read: How to improve tread life?
Better handling and stability
The better handling and cornering stability is calculated by the tire’s steering response. And in case of radial tires, that comes form the weight distribution.
Although on straighter paths, both radial and bias ply tires would provide similar performance, during cornering, as the weight of the tire gets to emphasize the most on shoulders, bias ply tires aren’t able to easily take it on due to their stiffness.
Radial tires on the other side, allow better weight maneuverability on each corners due to their malleable sidewalls, allowing for better steering response, which results in faster cornering.
Greater comfort
Comfort has to do with bumps absorption, and although it depends on the tread a lot, the internal construction of the tire also plays a major role.
Simply put, stiffer the construction, lesser the vibrations would get absorbed.
So with a more flexibility on sidewalls, you get a more comfortable tire with radial built.
Are radial tires tubeless?
Radial tires actually come in both. They can have tubes, or they can be tubeless. Though the ones without tubes are most common on passenger cars, light trucks and SUVs on the road today.
These “tubeless” tires basically come with a bead, which create an airtight seal, between the rim and the tire. While the other, well, they have tubes in them filled with air, and they are typically used in heavy-duty applications such as commercial trucking, off-road equipment and some agricultural machinery.
How to know if my tires are radial?
Well if you have the tire, and want to check for it, look at the sidewalls, there you’d find a letter “R” printed on, it stands for Raidal.
Also if you’re getting one and want to know what construction it’s having, just look at it’s size.
You’d see something like 265/70/R17. And here, the R in R17 tells you that it’s a radial tire.
Similarly Bias Ply tires have a letter “B” followed by a number, indicating the tire’s load carrying capacity and speed rating.
Related Read: How To Read Tire Sizes?
Conclusion
Radial tires are the newest technology in the tire industry. They’re gonna stay best until the airless tires will show up.
In summary, radial tires have cords running perpendicular to the direction of travel, providing better handling and fuel economy as well as a longer tread life than bias tires.
I hope the article was helpful. Let me know if you have any further questions. Have a safe ride folks!
