Just though I’d post a picture so everyone is sure what I mean:
The front wheels like like they are designed to hurt pedestrians that get too close.
Those are just the lug nut covers. Imagine how much more it would hurt pedestrians (and how stupid it would look) if the wheel were on the other way.
Some wheels are innies and some are outies.
Where a single axle has two wheels mounted on it (on each side), that’s commonly called a dually (scroll down to the first pic).
Most people incorrectly conflate wheels and tires as the same thing. The OP is talking about the rims, not the rubber.
Heck, some of the ones on semi trucks look like they’re straight out of a James Bond moving for shredding the tires of vehicles that get too close.
Of all the loose terms for the round things cars roll on, calling them “rims” is at the bottom of my list. Dunno why.
But yeah, I’ve seen more than one semi with 6-inch spikes sticking out from the lug nuts. Like, yeah, we get it, dude.
Just to get it straight about the tag axles on semi’s: Most places have limits on the axle loads for trucks to save damage to the pavement. When it’s loaded the extra axle is needed to spread the load and avoid delays and fines.
When the truck is light, air is evacuated from the suspension and the axle lifts. When you consider the cost of truck tyres, the saving is not insignificant, bearing in mind that when the truck turns, the tyres are dragged sideways.
Back in the days before tag axles, and super single tires there were duallies.
Picture a truck with a single tire on each side in the front and two tires on each side in the rear. By using the axle arrangement being discussed here all six rims are identical.
Makes life a lot easier for everyone.
But without the steel balls for your trailer hitch, you’re not really a stud.
all six wheels are the same. On the rear axle, each side has two wheels mounted on the hub, face-to-face. what you see is the “inner” side of the outermost wheel.
up front, where only single wheels are fit to the hub, you see the outer side. and the wheel mounts to the hub using a large spacer.
Okay, first of all, wheels are the steel or alloy metal things they mount tires on.
Federal law says the max you can put on an axle is 12,000 lbs. Add a tag axle, you can carry another 12,000 lbs. The biggest heavy hauler rig I ever saw had 22 axles. There were all sorts of “jeeps” involved and on the tail end was a jeep with an air compressor which I suspect had more to do with the air brakes than the air suspension.
Wheels on a big rig can be used in any position; steer, inboard drive/trailer, or outboard drive/trailer. Not the same for tires, though. And the inflation valves line up with the holes in the wheels, so you don’t need a special “L” shaped valve to be able to inflate an inboard tire.
Speaking from a nice comfortable office in the UK - How in heck are those things legal?!
they’re plastic. the second anything touches them they’ll bust right off.
Actually it puts me in mind of the charioteer in Ben-Hur, Who fitted sharp projections to the wheel hubs, to damage or remove wheels on opponents’ chariots. I know how that worked out!
For those reading - this post was from 2015. Current Axle loads are as follows:
Current truck size and weight standards are a blend of Federal and State regulations and laws. Federal law controls maximum gross vehicle weights and axle loads on the Interstate System. Federal limits are 80,000 pounds gross vehicle weight, 20,000 pounds on a single axle , and 34,000 pounds on a tandem axle group.
Compilation of Existing State Truck Size and Weight Limit Laws - FHWA Freight Management and Operations.
As I recall, the Federal limit on Steers was 12,000 lbs.
Years ago I owned a 73 Dodge D500 flatbed truck. It had a single tire/wheel combo at each front corner and duallies on the back. All 6 wheels were exactly the same. I had to do some wheel swapping after blowing the aft right inboard tire and I was unable to buy another tire the same size. I ended up buying 2 new tires, had them mounted on the aft right wheels then those were installed on the front. Both front wheels were then installed on the aft right. The only issue after this was not having a longer valve stem on the aft right inboard wheel that is normally installed on the aft inboard wheels.