Why are truck wheels different?

Our cars and trucks have all different kinds of wheels. The wheels on personal cars are often a fashion statement. If it's not the owner's style, it's the car designer's style.

Commercial truck wheels are all about function. Sure, you might see some polished aluminum wheels with spike shaped lugnuts, but most truck wheels are all about practicality.

The first thing you've probably noticed is that the front wheels look different from the rear wheels. That difference isn't so much the wheels themselves, but the way they are mounted. All of the wheels that are mounted next to the truck frame have the convex side mounted outward. This allows room for brake hardware on the inboard side. In the rear of the truck, a second tire is mounted on the same axle, this time, with the concave side facing out. This allows for shorter studs (bolts), a stronger arrangement.

A second visible difference has roots in technology, tradition, and thievery.

Most modern trucks have pilot style wheels. They look much like a basic car wheel with some holes around the edges and some bolts near the center. They are removed in one piece with the tire attached to the wheel.

Dayton or "spoke" style wheels are the older style. With this style, the tire and the outer rim are removed while the center star-shaped portion stays attached to the axle. The primary advantages of this style is that they are lighter weight and they require lower torque to install and remove. Roadside tire changes are much easier.



Dayton wheels were more popular longer on East Coast than they were out west.

The third difference we sill learn about is more difficult to see.

There are two types of pilot wheels: Stud pilot or Budd (the earlier technology) and Hub pilot. Stud pilot wheels are lined up (piloted) on the wheel studs (you might think of them as bolts). The lug nuts have a cone shape where they contact the wheel. Hub pilot wheels, the new and more common style, have washers under the lugnuts. The washers make the lugnuts appear a little larger in diameter.


In another post, I will address steel vs. aluminum, super singles, and rotational weight. Did I miss anything? Please let me know in the comments below.

A second visible difference has roots in technology, tradition, and thievery.Most modern trucks havestyle wheels. They look much like a basic car wheel with some holes around the edges and some bolts near the center. They are removed in one piece with the tire attached to the wheel.or "s" style wheels are the older style. With this style, the tire and the outer rim are removed while the center star-shaped portion stays attached to the axle. The primary advantages of this style is that they are lighter weight and they require lower torque to install and remove. Roadside tire changes are much easier. The other advantage to Dayton wheels is that they are incompatible with pilot wheels. That's why you see them on intermodal container chassis. A dishonest truck owner can't easily steal new tires from the trailer and install them on their truck.Dayton wheels were more popular longer on East Coast than they were out west.The third difference we sill learn about is more difficult to see.There are two types of pilot wheels:(the earlier technology) and. Stud pilot wheels are lined up (piloted) on the wheel studs (you might think of them as bolts). The lug nuts have a cone shape where they contact the wheel. Hub pilot wheels, the new and more common style, have washers under the lugnuts. The washers make the lugnuts appear a little larger in diameter.In another post, I will address steel vs. aluminum, super singles, and rotational weight. Did I miss anything? Please let me know in the comments below.

The mechanical making of a truck has always been a topic of amusement. One of such strange things you will find, reflects in the different shapes of the front and the back wheels. While you may find the truck rear wheels are concave, the front wheels are found to be convex. Let’s clear up the mystery as below.

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Concave Truck Rear Wheels Vs. Convex Truck Front Wheels

How come is it possible that the shape of the front wheels is different from that of the back wheels? This may sound strange, but every design and shape has a technical purpose behind it. Yes, the wheels arrangement is different but why is that so, let’s find out.

1. Rear Wheels Carry The Weight

The rear wheels carry most of the truck’s weight. The rear wheels are known to be single bearing hubs, unlike the front wheel that is mounted on double bearing hubs. One should also know that rear wheels usually have four wheels with two of them attached to one axle.

Further, the pair of wheels needs to be supported on the same hub. To do so, the rims are made to overlap one another in order to accommodate the wheels on the same hub. Now this explains the reason behind truck rear wheels being concave.

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2. The Front Wheels Need To Be Steered

Certain components help steering the front wheels. These components need some space to make way for the desired motions of the pickup truck. For your information, the braking disc and the drum are situated a bit outwards from the steering components, thus taking some space away from the steering axis.

In order for the steering components and brakes to be distantly placed, the wheel needs to bulge out outwards. This, in turn, explains the reason behind truck front wheels being convex.

3. Combining The Two Facts

On the front wheels, hub to hub width needs to maintain a sufficient distance. To facilitate the scenario, the wheels are mount in the convex position. In case, the front wheels are in the shape of a concave; a significant external offset is witnessed. Such a condition further results in over sensitiveness while steering.

Whereas, the two wheels on the rear side are mounted to a common mounting point while maintaining enough space between the two tires. To tackle the problem of gap between the tires, the rear wheels are concave shaped. In this way, even the weight carried by the rear wheels gets distributed equally. You could also refer to our maintenance tips for tips for avoiding truck overheating.

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Wrapping Up

This is the simple and clear reasons behind the concave truck rear wheel while the truck front wheels are convex. Lastly, remember everything is there for a purpose. Whether the wheels are concave or convex; the distribution is balanced for a safe ride down the roads. Reliable stability while driving along with effective weight distribution are two benefits of the respective shapes of the front and the rear wheels.