Spigot rings and spacers conundrum

Spigot rings and spacers conundrum

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227bhp

10,203 posts

127 months

Friday 26th August 2016
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CrutyRammers said:
227bhp said:
<STUFF>
That's not proof fella, that's just an anecdote where you have assumed a cause.

A bolted joint is held together by friction between the mating surfaces. This friction is caused by the bolts pulling the surfaces together. That's all. Nothing "hangs" on the bolts or the centre spigot once it's all tightened correctly.

There are wheel setups where the centre spigot takes the load. Wheels with single centre bolts (knock-offs), for example in F1. In those cases there is a massive, and importantly, tapered, central hub which runs the entire width of the wheel centre section. Not 3mm of plastic ring.
It never did it before and hasn't done it since, the only time it broke was when the spigot ring was missing.
I've never had a wheel shear studs off like that before, that's proof enough for me and considering the consequences of what could happen I don't think it's very clever to be suggesting to someone to test your theory otherwise.

If what you are saying is correct then what happens when people copper grease the mating faces to stop alloy wheels from bonding themselves on? There won't be much friction holding them then.

Mr2Mike

20,143 posts

254 months

Friday 26th August 2016
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PositronicRay said:
Bolts saves wally's putting the nuts on the wrong way, plus easier to change if you have aftermarket wheels.
You'll need to explain that, how is a bolt easier to replace than a nut if you need a different seating arrangement?

Camoradi

4,285 posts

255 months

Friday 26th August 2016
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I'm just pondering ordering some spigot rings for some new wheels for a Caterham and have just measured the depth of the centre spigot which is 2.85mm, and made of aluminium. I find it hard to believe that the weight of the car is expected to rest on that.

From the OP's pictures it looks like he has more than that protruding with the spacers fitted.

227bhp

10,203 posts

127 months

Friday 26th August 2016
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HorneyMX5 said:
Well yes my gramerz is not amaze balls. Sorry.

Anyway. We can argue all day on the internet about this and it'll just go round in circles. I don't use them based on years of experience and knowledge gained from friends who are qualified motorsport engineers who are involved in peddling cars round race circuits all over Europe.
You don't make sense so it is worth arguing over. It doesn't take much money or time to do the job properly, so why not?
It's a bit like having 5 wheel nuts in your hand, but only putting 4 on because some bloke on the internet said you don't need the last one.

Mave

8,208 posts

214 months

Friday 26th August 2016
quotequote all
227bhp said:
If what you are saying is correct then what happens when people copper grease the mating faces to stop alloy wheels from bonding themselves on? There won't be much friction holding them then.
That's why you shouldn't grease the hub faces. You're assembling the joint in a way it wasn't designed, and relying in safety margin / fitters cranking up the torque to prevent the joint moving and fatiguing the bolts / studs.

The load taken by the bolts in reacting acceleration and braking torque is probably 5 times the load taken to carry the car's weight - so if you need spigot rings to support the weight, then surely you also need something other than the bolts to transmit torque?

HorneyMX5

5,308 posts

149 months

Friday 26th August 2016
quotequote all
227bhp said:
HorneyMX5 said:
Well yes my gramerz is not amaze balls. Sorry.

Anyway. We can argue all day on the internet about this and it'll just go round in circles. I don't use them based on years of experience and knowledge gained from friends who are qualified motorsport engineers who are involved in peddling cars round race circuits all over Europe.
You don't make sense so it is worth arguing over. It doesn't take much money or time to do the job properly, so why not?
It's a bit like having 5 wheel nuts in your hand, but only putting 4 on because some bloke on the internet said you don't need the last one.
If you have them, use them. It makes fitting the wheels easier. All I'm saying is they are not in any way a load bearing part of the assembly, if they were they'd be interference fit or tapered and not made of cheap plastic!

I did actually have some plastic spigot rings on a set of wheels for my sprint car and I did use them once because I had them. I only used them once as they melted.

CrutyRammers

13,735 posts

197 months

Friday 26th August 2016
quotequote all
227bhp said:
CrutyRammers said:
227bhp said:
<STUFF>
That's not proof fella, that's just an anecdote where you have assumed a cause.

A bolted joint is held together by friction between the mating surfaces. This friction is caused by the bolts pulling the surfaces together. That's all. Nothing "hangs" on the bolts or the centre spigot once it's all tightened correctly.

There are wheel setups where the centre spigot takes the load. Wheels with single centre bolts (knock-offs), for example in F1. In those cases there is a massive, and importantly, tapered, central hub which runs the entire width of the wheel centre section. Not 3mm of plastic ring.
It never did it before and hasn't done it since, the only time it broke was when the spigot ring was missing.
I've never had a wheel shear studs off like that before, that's proof enough for me and considering the consequences of what could happen I don't think it's very clever to be suggesting to someone to test your theory otherwise.

If what you are saying is correct then what happens when people copper grease the mating faces to stop alloy wheels from bonding themselves on? There won't be much friction holding them then.
It's not "my theory", it's how it works. Part of engineering knowledge since nuts and bolts were invented. If the bolts sheared, you'd overtightened them, undertightened them, or simply hit the assembly with a force that exceeded its design limitations.

And as Mave said, putting grease on the mating faces is bad for exactly the reason that it reduces the strength of the joint. Fortunately, as with most engineering, there are large safety margins which allow people to get away with it.

russell_ram

321 posts

230 months

Friday 26th August 2016
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There are some posters on this thread who appear to lack an engineering education and some others who better understand how a bolted joint works. For the sake of clarity, anyone agreeing with OP's tyre fitter falls into the first group.

FiF

43,965 posts

250 months

Friday 26th August 2016
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russell_ram said:
There are some posters on this thread who appear to lack an engineering education and some others who better understand how a bolted joint works. For the sake of clarity, anyone agreeing with OP's tyre fitter falls into the first group.
Exactly, not to mention what's happening under load and why joint fixings have a specified torque to give the designed range of clamping pressure.

227bhp

10,203 posts

127 months

Friday 26th August 2016
quotequote all
Mave said:
That's why you shouldn't grease the hub faces. You're assembling the joint in a way it wasn't designed, and relying in safety margin / fitters cranking up the torque to prevent the joint moving and fatiguing the bolts / studs.

The load taken by the bolts in reacting acceleration and braking torque is probably 5 times the load taken to carry the car's weight - so if you need spigot rings to support the weight, then surely you also need something other than the bolts to transmit torque?
But people do, that's just it. PH members advise it:

http://www.pistonheads.com/gassing/topic.asp?t=650...

http://www.pistonheads.com/gassing/topic.asp?t=283...

And there is plenty more.

227bhp

10,203 posts

127 months

Friday 26th August 2016
quotequote all
Camoradi said:
I'm just pondering ordering some spigot rings for some new wheels for a Caterham and have just measured the depth of the centre spigot which is 2.85mm, and made of aluminium. I find it hard to believe that the weight of the car is expected to rest on that.

From the OP's pictures it looks like he has more than that protruding with the spacers fitted.
A ring held tightly in between an inner and an outer with no gaps is a very strong joint. Think about it, if it's trapped in tight where does the material go to to cause a failure? It can't. If it was a loose fit that is when it would fail.

HorneyMX5

5,308 posts

149 months

Friday 26th August 2016
quotequote all
227bhp said:
Mave said:
That's why you shouldn't grease the hub faces. You're assembling the joint in a way it wasn't designed, and relying in safety margin / fitters cranking up the torque to prevent the joint moving and fatiguing the bolts / studs.

The load taken by the bolts in reacting acceleration and braking torque is probably 5 times the load taken to carry the car's weight - so if you need spigot rings to support the weight, then surely you also need something other than the bolts to transmit torque?
But people do, that's just it. PH members advise it:

http://www.pistonheads.com/gassing/topic.asp?t=650...

http://www.pistonheads.com/gassing/topic.asp?t=283...

And there is plenty more.
Because they don't know any better. Ignorance doesn't defeat the laws of physics.

russell_ram

321 posts

230 months

Friday 26th August 2016
quotequote all
227bhp said:
A lot of stuff in a number of replies.
Please stop and accept that you (and a number of others) are just wrong in this case.

CrutyRammers

13,735 posts

197 months

Friday 26th August 2016
quotequote all
227bhp said:
A ring held tightly in between an inner and an outer with no gaps is a very strong joint. Think about it, if it's trapped in tight where does the material go to to cause a failure? It can't. If it was a loose fit that is when it would fail.
If it's tight, how is the wheel moving in relation to the hub surface in the first place?
You think that a couple of mm of ally or plastic spigot is taking all of the side loads which hit a wheel, seriously?

PhillipM

6,515 posts

188 months

Friday 26th August 2016
quotequote all
227bhp said:
It never did it before and hasn't done it since, the only time it broke was when the spigot ring was missing.
I've never had a wheel shear studs off like that before, that's proof enough for me and considering the consequences of what could happen I don't think it's very clever to be suggesting to someone to test your theory otherwise.

If what you are saying is correct then what happens when people copper grease the mating faces to stop alloy wheels from bonding themselves on? There won't be much friction holding them then.
Copper grease isn't a very good lubricant, it's an anti-seize, the reduction in friction over an old/dirty/wet flange isn't much anyway.
Anyway, you're wrong, the bolt force holds the wheels on, the hubcentric bit is exactly that - to centre the wheel to an acceptable amount of runout.
Give there's play between the wheel and the centre spigot (there has to be, otherwise you couldn't get the wheel on), how do you expect the hub to take the load when at best it might be touching at one spot, and at worse not at all?

227bhp

10,203 posts

127 months

Friday 26th August 2016
quotequote all
Nanook said:
227bhp said:
A ring held tightly in between an inner and an outer with no gaps is a very strong joint. Think about it, if it's trapped in tight where does the material go to to cause a failure? It can't. If it was a loose fit that is when it would fail.
How is it held in tightly? They're slack enough that you can just slide them on and off.
What when the wheel is fitted? It's tight then.

Camoradi

4,285 posts

255 months

Friday 26th August 2016
quotequote all
227bhp said:
A ring held tightly in between an inner and an outer with no gaps is a very strong joint. Think about it, if it's trapped in tight where does the material go to to cause a failure? It can't. If it was a loose fit that is when it would fail.
OK, then. I'm not disputing what anyone says. I want to be safe on the road. I've just put some masking tape over the spigot, and fitted a factory standard Caterham wheel, which has a chamfered entry to the wheel centre, and the tape is not marked. The wheel does not contact the spigot at all. The fact that the paint on the wheel is intact at this point seems to confirm this after 10,000 miles

Do I need to fit spigot rings or change my wheels?

PhillipM

6,515 posts

188 months

Friday 26th August 2016
quotequote all
227bhp said:
What when the wheel is fitted? It's tight then.
No it's not, they're not tapered, so it can't take the gap up.

SonicShadow

2,452 posts

153 months

Friday 26th August 2016
quotequote all
HorneyMX5 said:
When was the last time anyone came across wheels with a flat washer set up? I've not seen anything in 20 years of messing with cars that doesn't have tapered nuts/bolts.
Most Toyota's use flat seat nuts with washers on OE wheels.

EDIT- https://www.amazon.com/Toyota-90942-01062-Hub-Axle...

Edited by SonicShadow on Friday 26th August 12:02

227bhp

10,203 posts

127 months

Friday 26th August 2016
quotequote all
CrutyRammers said:
227bhp said:
A ring held tightly in between an inner and an outer with no gaps is a very strong joint. Think about it, if it's trapped in tight where does the material go to to cause a failure? It can't. If it was a loose fit that is when it would fail.
If it's tight, how is the wheel moving in relation to the hub surface in the first place?
You think that a couple of mm of ally or plastic spigot is taking all of the side loads which hit a wheel, seriously?
It isn't taking all of the load, I never claimed it was. They are all working together to hold the wheel in place.
I proved it by removing a ring, have four studs shear off whilst driving and the wheel falling off. If the spigots had been fitted it wouldn't have happened.