Grey

iTrader: (61)

Allright, I did a bunch of calculations and I came to the conclusion that it would take over 12,000lbs of force to break the frictional force of an aluminum wheel against the steel hub. The car itself exerts about 720lbs on each front wheel and a little less on the rear wheels. That's still more than 11,000lbs that it would take to seperate the wheel from the hub. That's just the frictional force though, then there are the hub rings and the wheel studs to overcome.

Anyway, I did this calculation to be sure that me not using any hub rings wouldn't be a big deal. Some people say that it's the hub rings that bear the weight of the car. According to this calculation the hub rings wouldn't really matter. I'm just wondering what kind of an event it would take to generate enough force to break this frictional resistence. I think hub rings are used mostly for wheel centering, but wheels can be centered without the use of hub rings.

Any ideas on this subject?

01civ01

your springs hold up the weight of the car, not hub rings. hub rings are used to fill the gap between the hub and the rim to reduce travel of the wheel.

Mbow

Hub rings are mainly used to center the wheel on the hub. Once the wheel is on they basically have no function whatsoever. A secondary benefit is that they fill the gap between the wheel and hub.

Grey

iTrader: (61)

Yes, thank you. I don't think you read or understood what I said, but that's okay.

Mbow: Yeah, that's what I gather. What I'm mainly looking for though is what kind of a force it takes to counteract the frictional force betwean the wheel and the hub.

duyaknow

iTrader: (9)

Grey,

I noticed that you must be an engineer or studying it because you always involve alot of physics into your technical replies. It's not a bad thing. It's actually very interesting because it's my first quarter of Physics this Fall and I'm learning about frictional forces and a bunch of other stuff. But anyways, you calculated that it would take 12,000 pounds of force to cause the hub to break from the aluminum wheel. Wondering where did you get the coeficient of friction from and how do you figuer out the force since the weight of the car is not perpendicular to the hub because of imperfect camber. Wouldn't that mean the normal force would have a trig value like (mg cos theta) x the coeficient of friction.

These calculations seem so complex because you gotta figure out certain data that would normally be given to you in a book...haha. I'm just amazed that you can relate all this car stuff to physics. Final will be 90% about momentum, relativity, and rotational forces involving torque.

Oh, and interesting question. You wonder what would be enough force to break the frictional force, plus the studs. I think I've seen on tv when ppl would lose wheels after flying like 8 feet in the air after driving too fast over a hill. Who knows for sure though, well, maybe physics can figure something out. For the idea of the hub rings, I don't think they support any weight, but possibly create an additional friction between the gap of the hub and wheel. Therefore eliminating extra movement and centering the wheel.