Alloy wheel spacers safe on steel wheels?

Alloy wheel spacers safe on steel wheels?

Author
Discussion

E-bmw

6,199 posts

119 months

Friday 11th June
quotequote all
Bye.

Mave

6,924 posts

182 months

Friday 11th June
quotequote all
Bye.

gmasterfunk

272 posts

115 months

Friday 11th June
quotequote all
https://link.springer.com/article/10.1007/s11668-0...

Interesting paper.

I'm off to tighten my nuts.

Edit its clamping force fiction.

stevieturbo

15,488 posts

214 months

Friday 11th June
quotequote all
aka_kerrly said:
Do you consider 5mm huge????

Plenty of 5/10/15/20/25mm spacers with hub centric fitment
I'd be shocked if the original spigot for alignment was less than 5mm, to enable what you say.

stevieturbo

15,488 posts

214 months

Friday 11th June
quotequote all
Mave said:
No, it 100% isn't. To transmit torque the bolt / stud would need to be in shear, which they aren't (or shouldn't be!), they are only in tension.

You need the bolt / stud fitted to be able to transmit torque because they are part of the joint, but they are not the part of the joint which transmits torque.

If the torque was taken by the bolts / studs, they would fatigue in no time (and you'd never get wheels stuck to hubs because they'd constantly be fretting!). It would also raise the question of why you actually need to torque up the nuts / bolts in the first place - you could just put a bit of threadlock on them, and nip them up by hand....
However, they both go hand in hand...you can't really achieve one without the other.

However, if the nuts were only tightened a small amount so things were very reliant on bolt shear....you can be fairly sure they would not last long.

Propshafts can be equally interesting...often bolted together by only 3-4 small M8 bolts. Then they get even weirder with the 3 bolt rubber joints...where the bolts are kinda in shear.

aka_kerrly

11,925 posts

177 months

Saturday 12th June
quotequote all
stevieturbo said:
aka_kerrly said:
Do you consider 5mm huge????

Plenty of 5/10/15/20/25mm spacers with hub centric fitment
I'd be shocked if the original spigot for alignment was less than 5mm, to enable what you say.
This is what I mean, a 5mm spacer that sits on an existing lip on the disc with a lip to support/centre the wheel correctly


E-bmw

6,199 posts

119 months

Saturday 12th June
quotequote all
gmasterfunk said:
https://link.springer.com/article/10.1007/s11668-0...

Interesting paper.

I'm off to tighten my nuts.

Edit its clamping force fiction.
Don't let Mave read that.

Mave

6,924 posts

182 months

Saturday 12th June
quotequote all
E-bmw said:
gmasterfunk said:
https://link.springer.com/article/10.1007/s11668-0...

Interesting paper.

I'm off to tighten my nuts.

Edit its clamping force fiction.
Don't let Mave read that.
What, the bit where it talks about friction at the clamping faces taking most of the torque? smile An increase in failure through fatigue being attributed to the bolts taking loading in shear? Did you actually read the paper, because it pretty much agrees with everything I said.

Edited by Mave on Saturday 12th June 11:38

gmasterfunk

272 posts

115 months

Saturday 12th June
quotequote all
Mave said:
E-bmw said:
gmasterfunk said:
https://link.springer.com/article/10.1007/s11668-0...

Interesting paper.

I'm off to tighten my nuts.

Edit its clamping force fiction.
Don't let Mave read that.
What, the bit where it talks about friction at the clamping faces taking most of the torque? An increase in failure through fatigue being attributed to the bolts taking loading in shear? Did you actually read the paper, because it pretty much agrees with everything I said.
My apologies. Autocorrect changed friction to fiction. Never thought that could be an issue!

Yes it is the majority done by friction, 40-100% of the work, dependant on pre load [fig 3] by Parisen. With the bolts doing some work under heavy load conditions or if not torqued enough, hence my comment regarding tightening my nuts. However as noted using the bolts does lead to fatigue and potential bolt failure.

Genuinely interesting subject as i didn't know the definitive answer as an engineer. I was leaning towards friction with my experience of hsfg bolts, but not certain. Also the second time in 2 days i came across the belleville spring and can see the interplay between bolt higher torque as you change from steel wheels to "stiffer" alloys.

Every day is a school day.

Mave

6,924 posts

182 months

Saturday 12th June
quotequote all
gmasterfunk said:
My apologies. Autocorrect changed friction to fiction. Never thought that could be an issue!

Yes it is the majority done by friction, 40-100% of the work, dependant on pre load [fig 3] by Parisen. With the bolts doing some work under heavy load conditions or if not torqued enough, hence my comment regarding tightening my nuts. However as noted using the bolts does lead to fatigue and potential bolt failure.

Genuinely interesting subject as i didn't know the definitive answer as an engineer. I was leaning towards friction with my experience of hsfg bolts, but not certain. Also the second time in 2 days i came across the belleville spring and can see the interplay between bolt higher torque as you change from steel wheels to "stiffer" alloys.

Every day is a school day.
I think the 40-100% was the range of the study - you can see later how increasing the clamp load reduces the stress cycles in the bolt - so you want to get as close to 100% as you can without getting to the point where the capability of the bolts starts dropping. All of the mitigations - surface roughness, re-torquing, etc are aimed at managing the clamp load over real world conditions to avoid fatiguing the bolts in shear.

The other bit which didn't jump out at me but I might need to read again more carefully is the effect of wheel thickness. With conical bolts, they aren't really ever in pure shear, it had a component of bending because you have clearance around the bolt thread. The conical surface acts like a pseudo ball joint, so you end up with the bolts / studs en caste in the hub, and acting like a beam in bending - exacerbated by thicker alloys because you get more moment arm.

Stiff systems are a right pain to design because the "noise" factors become the dominant variable, and don't leave you much room for manoeuvre. Thought it was interesting how 20-30% reduction in clamp load can make such a difference in fatigue life, you'd get that same difference with 20-30% reduction in friction coefficient...

Edited by Mave on Saturday 12th June 12:06

E-bmw

6,199 posts

119 months

Saturday 12th June
quotequote all
Mave said:
E-bmw said:
gmasterfunk said:
https://link.springer.com/article/10.1007/s11668-0...

Interesting paper.

I'm off to tighten my nuts.

Edit its clamping force fiction.
Don't let Mave read that.
What, the bit where it talks about friction at the clamping faces taking most of the torque? smile An increase in failure through fatigue being attributed to the bolts taking loading in shear? Did you actually read the paper, because it pretty much agrees with everything I said.

Edited by Mave on Saturday 12th June 11:38
Who didn't read these parts then?

"Wheel attachments, as the term implies, consist of the wheel nuts and wheel bolts which serve to secure the road wheels of a vehicle to the rotating axles or stationary hubs. Their principal function is to provide a means of transmitting the gravitational, dynamic, driving, braking, and steering forces and torques between the wheels and the driveline, steering, and suspension components. "

"The mechanics of securing the wheel to its mating component (i.e., a brake drum or rotor) is the same for both bolt-piloted and hub-piloted systems: the radial and torsional road loads are all transferred from the wheel through a combination of the friction connection between the wheel and its mating component, and the shear and bending forces applied by the wheel through the wheel nuts to the wheel bolts. The friction connection is created by the “clamp force” that arises during the tightening of the wheel nuts on the wheel bolts. Tightening the nut “stretches” the bolt and clamps the wheel tightly against its mating component. This clamping action and the resulting friction connection between the wheel and rotor or drum resists any tendency for the wheel to move relative to its mating component under the influence of the applied road loads or acceleration or braking torques."




Mave

6,924 posts

182 months

Saturday 12th June
quotequote all
E-bmw said:
Who didn't read these parts then?

"Wheel attachments, as the term implies, consist of the wheel nuts and wheel bolts which serve to secure the road wheels of a vehicle to the rotating axles or stationary hubs. Their principal function is to provide a means of transmitting the gravitational, dynamic, driving, braking, and steering forces and torques between the wheels and the driveline, steering, and suspension components. "

"The mechanics of securing the wheel to its mating component (i.e., a brake drum or rotor) is the same for both bolt-piloted and hub-piloted systems: the radial and torsional road loads are all transferred from the wheel through a combination of the friction connection between the wheel and its mating component, and the shear and bending forces applied by the wheel through the wheel nuts to the wheel bolts. The friction connection is created by the “clamp force” that arises during the tightening of the wheel nuts on the wheel bolts. Tightening the nut “stretches” the bolt and clamps the wheel tightly against its mating component. This clamping action and the resulting friction connection between the wheel and rotor or drum resists any tendency for the wheel to move relative to its mating component under the influence of the applied road loads or acceleration or braking torques."
I read and understood all that thanks. And it disagrees with your statement "The torque is 100% transmitted to the wheel via the bolt/stud" doesn't it?

Did you read all the report? I mean, you could summarise it as "wheel started falling off, and when we investigated, we found out it was because clamp loads were dropping, and so bolts were fatiguing in shear and bending". They then discussed lots of ways to keep the clamp load up, which kinda agrees with my original comment, that you want to keep the faces carrying the torque, not the bolts.

Edited by Mave on Saturday 12th June 22:00

E-bmw

6,199 posts

119 months

Sunday 13th June
quotequote all
This was you the other day:

Mave said:
At the risk of opening up the old chestnut - don't put copper grease on the mating surfaces. If you absolutely must then just a little bit around the edges to stop the moisture getting in - but those surfaces are transferring the torque from the wheel to the hub / spacer.
This was in the paper:

"Wheel attachments, as the term implies, consist of the wheel nuts and wheel bolts which serve to secure the road wheels of a vehicle to the rotating axles or stationary hubs. Their principal function is to provide a means of transmitting the gravitational, dynamic, driving, braking, and steering forces and torques between the wheels and the driveline, steering, and suspension components. "

As was this:

"The friction connection is created by the “clamp force” that arises during the tightening of the wheel nuts on the wheel bolts. Tightening the nut “stretches” the bolt and clamps the wheel tightly against its mating component. This clamping action and the resulting friction connection between the wheel and rotor or drum resists any tendency for the wheel to move relative to its mating component under the influence of the applied road loads or acceleration or braking torques."

Discuss.

AW111

6,856 posts

100 months

Sunday 13th June
quotequote all
E-bmw said:
This was you the other day:

Mave said:
At the risk of opening up the old chestnut - don't put copper grease on the mating surfaces. If you absolutely must then just a little bit around the edges to stop the moisture getting in - but those surfaces are transferring the torque from the wheel to the hub / spacer.
This was in the paper:

"Wheel attachments, as the term implies, consist of the wheel nuts and wheel bolts which serve to secure the road wheels of a vehicle to the rotating axles or stationary hubs. Their principal function is to provide a means of transmitting the gravitational, dynamic, driving, braking, and steering forces and torques between the wheels and the driveline, steering, and suspension components. "

As was this:

"The friction connection is created by the “clamp force” that arises during the tightening of the wheel nuts on the wheel bolts. Tightening the nut “stretches” the bolt and clamps the wheel tightly against its mating component. This clamping action and the resulting friction connection between the wheel and rotor or drum resists any tendency for the wheel to move relative to its mating component under the influence of the applied road loads or acceleration or braking torques."

Discuss.
OK, I'll discuss.

Mave said that it's the friction between the wheel and hub that transfers most of the torque.
The posted article agrees, as do other sources.

The bits you quoted also agree with that interpretation.


So what is the point you're trying to make?

Mave

6,924 posts

182 months

Sunday 13th June
quotequote all
E-bmw said:
This was in the paper:

"Wheel attachments, as the term implies, consist of the wheel nuts and wheel bolts which serve to secure the road wheels of a vehicle to the rotating axles or stationary hubs. Their principal function is to provide a means of transmitting the gravitational, dynamic, driving, braking, and steering forces and torques between the wheels and the driveline, steering, and suspension components. "

As was this:

"The friction connection is created by the “clamp force” that arises during the tightening of the wheel nuts on the wheel bolts. Tightening the nut “stretches” the bolt and clamps the wheel tightly against its mating component. This clamping action and the resulting friction connection between the wheel and rotor or drum resists any tendency for the wheel to move relative to its mating component under the influence of the applied road loads or acceleration or braking torques."

Discuss.
Not sure what there is to discuss. What you've quoted agrees with what I've said. The joint is designed to use friction to transfer loads. The ability to transfer loads through friction comes from a combination of clamp load and friction coefficient. If you drop the friction coefficient by greasing the surfaces which transfer the load, then less load can be transmitted before the joint slips.

E-bmw

6,199 posts

119 months

Sunday 13th June
quotequote all
E-bmw said:
This was you the other day:

Mave said:
those surfaces are transferring the torque from the wheel to the hub / spacer.
This was in the paper:

"Wheel attachments, as the term implies, consist of the wheel nuts and wheel bolts which serve to secure the road wheels of a vehicle to the rotating axles or stationary hubs. Their principal function is to provide a means of transmitting the gravitational, dynamic, driving, braking, and steering forces and torques between the wheels and the driveline, steering, and suspension components. "

As was this:

"The friction connection is created by the “clamp force” that arises during the tightening of the wheel nuts on the wheel bolts."

Discuss.
I have now made it really easy for you.

Surely even you can see these are not in agreement with your statement that it is the hub/wheel surface friction that transfers the torque to the wheel?

Mave

6,924 posts

182 months

Sunday 13th June
quotequote all
E-bmw said:
E-bmw said:
This was you the other day:

Mave said:
those surfaces are transferring the torque from the wheel to the hub / spacer.
This was in the paper:

"Wheel attachments, as the term implies, consist of the wheel nuts and wheel bolts which serve to secure the road wheels of a vehicle to the rotating axles or stationary hubs. Their principal function is to provide a means of transmitting the gravitational, dynamic, driving, braking, and steering forces and torques between the wheels and the driveline, steering, and suspension components. "

As was this:

"The friction connection is created by the “clamp force” that arises during the tightening of the wheel nuts on the wheel bolts."

Discuss.
I have now made it really easy for you.

Surely even you can see these are not in agreement with your statement that it is the hub/wheel surface friction that transfers the torque to the wheel?
Let's take a look at the statement again by including the contextual words you omitted, my commentary in brackets...

"the radial and torsional road loads (note, this includes reference to torque) are all transferred from the wheel through a combination of the friction connection between the wheel and its mating component (the wheel and the hub or spacer surfaces).....

The friction connection is created by the “clamp force” that arises during the tightening of the wheel nuts on the wheel bolts."

Nope, I can't see where this disagrees with what I wrote.

To make things clearer, here is my summary of the key points of that paper relevant to this discussion -

1) wheel loads (including torque) are transferred by a combination of bolts in shear / bending, and friction across the hub / wheel surfaces
2) shear / bending is taken by the bolts directly
3) friction across the hub / wheel surfaces is provided by the bolts clamping in tension
4) allowing the bolts to take too much load in shear / bending can cause fatigue failure
5) to avoid fatigue failures, mitigations have been introduced to increase the proportion of road loads carried by friction, and reduce the proportion of road loads carried in shear.

Do you disagree with any of those points? Have I omitted any relevant points?

Edited by Mave on Sunday 13th June 13:19

E-bmw

6,199 posts

119 months

Sunday 13th June
quotequote all
Mave said:
Let's take a look at the statement again by including the contextual words you omitted, my commentary in brackets...

"the radial and torsional road loads (note, this includes reference to torque) are all transferred from the wheel through a combination of the friction connection between the wheel and its mating component (the wheel and the hub or spacer surfaces).....

The friction connection is created by the “clamp force” that arises during the tightening of the wheel nuts on the wheel bolts."

Nope, I can't see where this disagrees with what I wrote.
OK, lets look at your own argument above in a bit more detail making it as simple as I possibly can.

The torque is transferred to the wheel through the friction connection.

The friction connection is created by the clamping force.

How on earth does this agree with your opinion that greasing the wheel hub/wheel surface will affect how torque is transmitted to the wheel/road?

AW111

6,856 posts

100 months

Sunday 13th June
quotequote all
This is now getting funnier all the time!

I await the next post with interest.

Mave

6,924 posts

182 months

Sunday 13th June
quotequote all
E-bmw said:
OK, lets look at your own argument above in a bit more detail making it as simple as I possibly can.

The torque is transferred to the wheel through the friction connection.

The friction connection is created by the clamping force.

How on earth does this agree with your opinion that greasing the wheel hub/wheel surface will affect how torque is transmitted to the wheel/road?
I don't see any obvious inconsistencies in those points. What's the problem with them?

Where do you think that the friction connection referred to above actually is?

Edited by Mave on Sunday 13th June 14:34