Redrilling wheels - has this guy found the limit?

I still don't know whats stopping your wheels from moving under acceleration or braking though. You only stopped them from moving up and down with your spigot rings.

 

So, Ronal, a wheel manufactuer states that the bore size should match the hub. good enough for me.

 

FAO, anti spigot ring masif

 

The anti spigot ring masif (which I'm not a member of but support theyre views, I like a safety factor in design to feel a spigot is good for this) theory states that the clamping force of the wheel bolts creates enough friction between the jointed surfaces such that the wheel bolts do not come under any shear forces. Therefore this argument does not apply to properly torqued wheels.

 

Feel free to test out your THEORY, and have your widow contact us with the results.

Is your theory with or without copaslip?

Personally, I'll stick with the practice of every car manufacturer, race team, rally team, wheel manufacturer..... and just take the coward's way out.

 

I think we're seeing a poor input from the defence today - they seem to come and go as they please

Has anyone called in sick?

 

Clamping force of 4 wheel bolts at 80Nm = 133455 N

Friction Coefficient steel to aluminium dry = 0.61
Force Required to create shear movement in joint when dry = 81407 N

Friction Coefficient of greased steel to cast iron = 0.21
Force Required to create shear movement in joint when dry = 28026 N

Friction Coefficients may not fully represent materials used in wheels and hubs/discs. These are rough estimations. The greased coefficient I feel maybe rather low in this situation as most of the grease will be squeezed out in the tightening process. But shown nonetheless.

I guess that 2.8Kn loads might occur in rallying if hitting rocks etc, but I doubt your going to see that on a track though. Anyone care to comment?


Consider a modified mk2 on 4 studs with a tdi in it maybe ~350Nm Is creating a shear force of 70000N at the Studs. Therefore the joint will probably slip with copper grease in there, but not when dry as intended. But this would not be affected by the use of spigot rings. Standard MK2 16v ~170Nm 34000N Plenty of safety factor in dry clamping force there. A designer of a newer car with 350Nm of torque uses 5 bolts at m14 on a 112mm PCD for a reason. Increased clamping force...

Maybe copper grease although saving hassle for you is not what the designer intended to be in their joint? Have you ever seen it reccomended in a factory service manual?

 

None of the NEW cars i have bought have ever had lubrication between the wheel and hub....

So greasing and operating outwith the intended design, that changes things. . . .

 

My god, you always miss the pont don;t you.

No one is ANTI spigot rings, but some of us know that thay are not nearly as important as you seem think they are.

FYI, all my wheels are located centrally on the spigot, because they are OEM, and if i have spigot rings i fit them, for convenience when removing and refitting wheels. But it wouldn;t stop me using the car if one was missing.

 

The prosecution would like to ask the defence to explain why OEM mfrs + aftermarket suppliers of all tiers fit spigot rings, when they could otherwise save a lot of money by having one less variable

 

Lots of alloy wheels have differences in the mounting faces that mates to the drive flange / disc. Some have recesses formed by manufacturing process that would reduce the surface area of the two mating surfaces in contact with each other. It could be that some of the issues of wheels coming slack has arisen form this reduced surface area being effectively clamped and therefore more susceptible to movement.

I lap my flywheels to the crank to ensure there is as large a surface area in contact between the two mating surfaces as possible. Rosten performance produce a diamond impregnated shim to assist in the clamping of these components too.

 

A safety factor for if wheel bolts are incorrectly tightened and to aid the fitting of wheels in manufacture and service.

 

The prosecution would like to ask the defence: is this safety factor necessary and are the manufacturers are squandering money by doing it?

 

Proof that spigot rings are required.
The lead singer used to have great blond hair as he preached about not needing these groove thangs! However the oscillation and vibration he suffered whilst driving his vehicles sans spigots caused his hair to fall out.

Now look at him FFS! We don't need this fascist groove thang. Are you sure?

[YOUTUBE]uWs1-2foKoo[/YOUTUBE]

 

This safety factor is necessary if the bolt tightening process cannot be guaranteed correct, poor bolt tightening leading to lack of clamping force and wheel loads being transferred as shear through wheel bolts and the spigot.
They are saving money by doing it in terms of assembly time, not squandering money at all.

 

Have you ever seen 'slacken the wheel bolts and do a handbrake turn to get the wheels loose' in a factory service manual? That's what you'll be doing if you run G60 steels and no grease.

What's the rough load of a 1 tonne car hopping a 6" kerb - estimate a 45 degree angle (I tried to measure the angle more accurately, but Chris ran over my protractor ) at 120 mph, and then jumping off the kerb at the other side? Those are your real life track loads. Or what's the load of hitting a 1ft wide, 6" deep pothole at 80 mph on the public road?

You boys just ain't living in the real world.

 

This argument is a classic, facts from the educated and relevantly experienced vs pub knowledge inferred from in this case some quite varied experience.

A fact i'd like to put out there is i have a masters in Mech eng from a good uni. I have over 3 years in automotive OEM design (i actually design this stuff). Not bragging but if someone was coming to me with some fact which went against what i had previously presumed/thought then i'd want to know their background.

The spigot ring is purely for locating the wheel centrally while it is mounted, afterwards the clamp load from the bolts is responsible for holding the wheel where it is. This is the way that joint is designed, if you go a long way outside the intended use or assemble not as intended then things may change, but if the wheel moves on the hub there is a very great chance of total failure of the bolted joint.

I've never seen an OEM use spigot rings, they just design the wheel with the right ID - no added cost. After market wheels use spigot rings, increase your potential customers with relatively small outlay.

 

I wonder how strong your alimghty spigots are. They aren't exactly a design for strength. The defence would like to ask the prosecution for an analysis into the strength of aforementioned spigot.

 

Let's not get lost in a sub argument. For sake of discussion, spigot or correct OEM ID = same.

 

Some do give direct instructions on exactly where a lubricant should be used, and what sort of lubricant it should be, to maintain bolt tightening torque.
Porsche for example are very specific on this:
On the bolt threads and under the head of the bolts, between bolt head and conical washer (to ensure correct torque) and on the 3 raised prongs of the spigot (no resist galvanic corrosion).

Lubricant should be a copper grease as listed in PET.