Reinventing the Wheel - PeachParts Mercedes-Benz Forum

imdavid28 · #1 02-21-2006, 11:15 AM

Bit of a weird question, but any way...

What exactly supports the weight of your car? Is it the static friction between the wheel and the brake rotor with the lugs providing the natural force, or is it a combination of that and the bending of the lugs. Anybody know for sure?

Reason why I am asking is because if it is simply because of the static friction, why wouldn't you be able to use a simple spacer that is a desired thickness with holes to clear the lugs? I have seen this on the back of an IROC-Z before, don't know if it was factory or not.

Hatterasguy · #2 02-21-2006, 11:23 AM

If you are talking about the wheels the lug bolts do not support the weight of the car. The center of the wheel rides on the hub, thats what supports the car.

With a spacer like the one you describe you risk the wheel actually coming off.

http://www.hrsprings.com/site/index.html

Thats the kind fo spacer you need. Figure about $200-$300 for a set.

Nate · #3 02-21-2006, 11:47 AM

Quote:

Originally Posted by Hatterasguy

If you are talking about the wheels the lug bolts do not support the weight of the car. The center of the wheel rides on the hub, thats what supports the car.

With a spacer like the one you describe you risk the wheel actually coming off.

http://www.hrsprings.com/site/index.html

Thats the kind fo spacer you need. Figure about $200-$300 for a set.

But dont the lug nuts/bolts force the wheel into the hub? If you put longer studs in (or use longer bolts) wouldnt that just be a hub "exetntion?

Id just get wheels with the proper offset, but what do i know?

~Nate

Hatterasguy · #4 02-21-2006, 12:18 PM

Well of course buying wheels with the proper offset is the right thing to do. But if everyone did that where would be the challange!

The center of the wheel fits over the hub and holds the car. The bolts seem to only hold the wheel onto the hub. They don't support the weight of the car. If you slip a spacer in their and then all of a sudden the center of the wheel is not supported by the hub anymore, but by the bolts you risk them failing.

The H&R spacers are hub centric Ie they extend the hub.

The downside of useing H&R spacers is if you go to far they wheels will stick out past the fenders like a cheap Honda.

imdavid28 · #5 02-21-2006, 04:05 PM

Yeah, I guess your right. Forgot about that for some dumb reason..... Oh well

Chris W. · #6 02-22-2006, 12:59 PM

I believe it is the clamping force of the wheel on the face of the hub, not the actual ring of the hub in the center. The friction between the wheel and the hub is the carrier of the weight.

I believe you could in theory grind away that raised ring on the hub and the car would be supported just fine. The hub provides the centering to correctly locate the wheel, but does not support the car's weight.

Rgds,
Chris W.
'95 E300D

deerefanatic · #7 02-22-2006, 01:21 PM

Yes my friend, it does. Take the bolts out of a benz after about 25000 miles (asuming that they were correctly tightened that is) and you will see. Sledgehammer is in order to get the wheels off.

All lateral forces removed (a technical impossibility) and you wouldn't even need bolts after the wheel is mounted tight. The thing is, even the air puts lateral force on the wheel, hence the need for bolts all the time in the real world.

imdavid28 · #8 02-22-2006, 02:07 PM

Quote:

Originally Posted by deerefanatic

Yes my friend, it does. Take the bolts out of a benz after about 25000 miles (asuming that they were correctly tightened that is) and you will see. Sledgehammer is in order to get the wheels off.

All lateral forces removed (a technical impossibility) and you wouldn't even need bolts after the wheel is mounted tight. The thing is, even the air puts lateral force on the wheel, hence the need for bolts all the time in the real world.

Ok, so follow my theory-

If you install the wheel, and sequentially tighten the lugs so that each one centers the wheel, you would not need the center section of the wheel, therefor you could simply make a flat spacer with no centering hub in the middle, and use longer lug nuts?

deerefanatic · #9 02-22-2006, 02:51 PM

No, you missed my point. The lugs bolts are just to hold the wheel on the hub; the hub carries the weight. (And transfers engine power or braking force)

Just look at the hub, the cross section of it is at least 4+ times as large as the cross sections of all the lugs put together. Hence, it has much better load bearing ability.

I wouldn't take the risk if it were my skin that was riding in that car!

imdavid28 · #10 02-22-2006, 04:24 PM

Quote:

Originally Posted by deerefanatic

Yes my friend, it does. Take the bolts out of a benz after about 25000 miles (asuming that they were correctly tightened that is) and you will see. Sledgehammer is in order to get the wheels off.

I assumed you were talking about the vertical section of aluminum on the back of the wheel that mates with the brake rotor, not the small inner diameter of the wheel that slides over the hub that was causeing this.

My orginal assumption was that the weight was supported by the friction between the wheel and the rotor, not the hub and that small inner diameter on a wheel.

Hatterasguy · #11 02-22-2006, 07:09 PM

Quote:

Originally Posted by imdavid28

Ok, so follow my theory-

If you install the wheel, and sequentially tighten the lugs so that each one centers the wheel, you would not need the center section of the wheel, therefor you could simply make a flat spacer with no centering hub in the middle, and use longer lug nuts?

Sure you can just make sure your medical and life insurance are paid up. That is exactly what will cause the lug bolts to shear off and the wheel to come flying off.

The lug bolts on MB's only provide clamping force to hold the center of the wheel to the hub. If you ask the lug bolts to support the weight of the car, well they are not built for that. They may last a while but it is only a matter of time....

Look at the H&R spacers, that style is the only type that belongs on a MB period.

deerefanatic · #12 02-22-2006, 10:15 PM

Quote:

Originally Posted by Hatterasguy

Sure you can just make sure your medical and life insurance are paid up. That is exactly what will cause the lug bolts to shear off and the wheel to come flying off.

The lug bolts on MB's only provide clamping force to hold the center of the wheel to the hub. If you ask the lug bolts to support the weight of the car, well they are not built for that. They may last a while but it is only a matter of time....

Look at the H&R spacers, that style is the only type that belongs on a MB period.

.........Or any other wheel for that matter!

imdavid28 · #13 02-23-2006, 08:58 AM

Too bad there is only one of them.

http://cgi.ebay.com/ebaymotors/mercedes-benz-H-R-spacer-1-N-R_W0QQitemZ8039970873QQcategoryZ42614QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Anywhere else you know of to get them?

Nevermind, I found them.

http://www.optionimports.com/h-r-spacer-benz.html

t walgamuth · #14 02-23-2006, 09:03 AM

the other.

the hub and bolts work together.

i do think that many other cars do without the tight fitting center hub though. so i think that the center is mainly to insure correct alignment. the lugs have tremendous holding power.

in a skyscraper, the bolted connections in the steel beams create friction which locks the joint all together as strong as if it were welded. the bolted connection creates a joint "that develops the full strength of the beams/ columns being connected".

it will be the same in a car.

tom w

locry · #15 02-23-2006, 11:10 AM

hmmmm, i 've asked myself this question a while back... it seems everyone has a point...

but what about the actual torque from the drivetrain?
Assumption "A" states: "the center hub is what carries the weight of the car, and therefore more significant than the bolts" , what happens when you have a powerful motor that generates enough torque to exceed the weight of the car and SHEARS off the bolts?

I think the more important question is what holds and centers the wheel to the hub. Answer? BOTH.

The bolts by themselves can and will hold the weight of the car when not in motion. When in motion and therefore subjected to more significant forces like torque, which then overpowers weight, the bolts' ability to hold the wheel AND keeping it centered to the hub lowers significantly.(i think)

Therefore, it needs a central anchor point which theoretically is immovable like the hub.