Question about big semi-trucks???

Question

I've noticed that the front tires of semi-trucks have hubcaps that point out and the tires on the back have hubcaps that point in. It seems very standard on all semi-trucks for this, so I suspect that there is a purpose for it. Does anyone know why?

Answer 1

All the wheels on the truck are exactly the same. The ones on the rear axle are turned around, opposite of the front ones so that they will fit on the truck. IE: the inside back wheel is mounted same as the front wheel. The outside rear wheel must be turned around to fit on the lug bolts.

Answer 2

It is not so that it is easier to change tires.

Notice that the rears are dual tires (two tires right next to each other). This is to increase the load capacity and reduce the amount of sway from sidewall flex.

The reason for the wheels to stick out in the front is because of the design of the wheel. THe face of the wheel sticks out slightly farther than the sidewall of the tire, so that when two tires are placed on the rear, there is a space between them so that they do not rub.

When mounting the tires on the rear, the inner tire is turned the same direction that the front is (so that the wheel sticks out away from the center of the truck), then the outer tire is turned so that the wheel sticks inward toward the center of the truck. So now the wheel faces are contacting each other, but there is a gap between the rubber tires, and only one set of lugnuts is required to hold both wheels on.

On the fronts, they are turned in the fashion that they are to reduce the amount of stress on the axle and steering components. If they were spun the opposite direction, the extra leverage from the tires would increase wear on the front end.

Answer 3

That is a very good question.  I am amazed at the stupid answers you got, but of course 2 are correct.

I am going to try to make this as short as possible.

In order to create DUAL wheels, it is necessary that the wheel mounting surface sticks out completely beyond the edge of the tire.  These wheels, when mounted on the truck, look different depeneding on which side you're looking at.

Answer 4

easyer to change a flat tire.

Answer 5

Well, just in case any tyre is flat, it is easy for replacement...

Answer 6

here is a blog on semi trucks and also about other useful tips on trucks and accessories

http://blog.usedsemitrucksforsale.net

Its not mine but u can refer it.

Answer 7

for easy change in tires