Troyman,

I know what you mean. I have CSA ultra's on my car, but they do contact the hub.

The problem is aftermarket rims are cast to fit cars "X, Y and Z", then have the stud holes drilled, and you then rely on the manufacturer, their design processes and govt/industry standards.

If a rim is cast/made to suit car "X" and used on car "Y" without engineering it's all down to the owner, adaptor or not.

A good example of this is on the original shape Range Rovers. Early ones (70's - '86 ish) had steel rims, later ('87-93/94) had alloy rims. A lot of people like the look of the alloy rims on the early 2 door Rangies. One problem, the later Range Rovers had smaller diameter hubs, and the rims were made to fit. Machining of the centres is required (increase hole diameter by 5mm) to fit the alloys to an older Rangie. And to fit steel rims to a later Range Rover, you are left with a gap between the rim and hub.

I guess in the long run it is up to the owner to ensure their car is safe.

Chris

i think its a lucky dip with these things. I have 20's on my car, slammed, 4.11's and spooled. Skate the thing everywhere and all is good???

mine should be ready in about 2-3 weeks as they are getting done when the old man has free time, but that being said they are being specially done for my rims and im using proper studs that wont s**t themselves (most likely going to get some out of another ford from the wreckers as they are good quality!)

the STUDS are always the issues with things like this yet the spacer gets blamed pre-maturily (spelling...)

Er, the centre spigot (whatever it's called) DOES carry the weight of the vehicle. The studs do not, they just hold the wheel to the hub face.

Mike

The centre bearing carrier as well as the studs and alike all play a part in

A) holfing the wheel onto the rotar etc
B) and takes the weight

Thats crazy, lucky you checked them before a wheel fell off.

This is ridiculous theres 2 different situations being talked about here......
For starters the centre hole on factory rims are always going be extremely close to the the size of the factory spigot/ hub therefore you could say that "MOST" of the weight will be resting around the hub.
However in some situations ie; aftermarket rims its a little bit bigger!
So therefore most of the weight will be held on the studs! otherwise the whole frigin wheel will be bouncing around on the hub due to the gap it has between that and the inside of the wheel hole!

If someone thinks thats not right then stay away from me if your on the road cos i dont trust you with changing wheels!

i aggree with you there!
every time ive heard that wheel spacer have failed! on here and other forums..
its actually the cheap a** studs snapping or the wrong nuts have been fitted causing the wheel to come loose or fall off.....

I've broken the factory studs before... but never broken those on my adapters.
infact, i've busted 2 rims (Dinted outer, cracked inner) and the adapters were fine.


moral of the story.. don't use the factory studs.. just don't bolt wheels to your cars, its too dangerous.

If the centre hub was to actually carry the load of the wheel, it would need to be a super hard press fit.

Lets look at some actual figures....

Car weight = 2000kg = 19620 N
Extreme case loading (all weight on one wheel) = 3924 N / stud
Shear capacity of M12 grade 8.8 bolt = 39,000 N
That's a safety factor of 8.9 with having all the weight of the car on one wheel.

Sure its a simplified look at it, and there would also be tension placed on top few studs (imagining the wheel trying to lean over during cornering), but there would also not be the full load of the vehicle on ONE wheel.

If you look into the friction of the joint between wheel and hub face you end up with a similar picture.
Coefficient of friction of aluminium to mild steel = 0.61
Ajax bolt guide Recommended tightening of a 12mm Grade 8.8 bolt = 77 Nm which converts to 31800 N tension.
Total tension at joint of ONE wheel = 159,000 N
Friction force of ONE wheel = 159000*0.61 = 96990 N
Car force (TOTAL) = 19620 N

So again if we put all the load on ONE wheel the safety factor is 4.9.


Now this is looking at these things separately.
If the vertical load is never enough to overcome the friction then the studs will NEVER take any load in shear.
If the vertical load does overcome the friction, then the studs would start to take the load. Not all of it though as the friction would still be assisting.


Now most wheel studs are what's called 'grade 8' which is basically the imperial version of the metric 'grade 10.9'
I didnt use grade 10.9 because I wanted to show the worst case situation, and th ebook I have doesnt show the shear strength of grade 4.6.

Lol.

O, and fo anyone who wants to argue that the centre ring on the hubs carries the weight of the vehicle. Autospeed did an article on a brand new (at the time) BA XR6 with the original genuine Ford alloys. They took it to a wheel repair shop and this guy made rings to go in the centre bore of the wheels so that they were in contact with the spigot on the hubs, they found this reduced vibrations. But my point is that it goes to prove that even Ford don't make there wheels to sit on the centre spigot, so to then try and say that it should be carrying all the weight is a big call.
I've spoken to the local engineer and wheel repairer here and they're only for locating according to him. Either way I have had my hub adapters made up with thick centre spigots and the back of the wheels machined to suit. And I like many hub adapter users here have not had an issue in the 5 years I've been running them.

I was working at a place that was a mechanical repair joint as well as a wheel & tyre joint too.
We had a problem with some wheels on a Lancer.....or was it a Mazda???....anyway, had vibes from the wheels, they were balanced several times, rotated, but to no avail.
I made some spacers out of hard Nylon, to locate the mag to the spigot ( none were available for the size required ), and the problem was solved.

supplied with my 18x8 wheels from argy tyres.280$
they told me specifically not to use a rattle gun
they have metric 10.9 on the studs.custom nuts

This is a very inaccurate way of looking at it. The standing weight of the car can hardly be used alone to calculate the shear stresses involved when cornering at high speed.

You obviously didnt read it very well as you'd see that I did say that it wasnt entirely accurate and did simplify things, and because you didnt see that I guess you didnt notice that I put ALL of the car weight on ONE wheel and still ended up with a safety factor of 8.9. That works out to be 17.8 Tonnes on one wheel. You'd also notice I did these calcs with a LOWER grade bolt.
A grade 8.8 bolt has a yeild stress of 640MPa, and grade 10.9 has a yeild of 900MPa. Now I dont have the Ajax book here to tell me the actual increase in shear strength but lets just say it is proportional to the yeild and therefore is an increase of 40%. Now one wheel can support 24.9 Tonnes.

I dont know how much extra weight would be placed on the wheel during hard cornering, but I do know that the minimum tyre load rating for an EL is 600kg, I'd imagine it probably wouldnt hold up to 24.9 Tonnes of weight on it.