Wheel Spacers - Opinions
Discussion
JB! said:
you need to see porsche adapters that have been on a Mk2 golf through a few winters with no copper slip!
you need a hammer and chisel to get them off!!!
And yet my hub adapters just undo and fall off. Makes me wonder if the spec of the annodising on the adapter might be critical.you need a hammer and chisel to get them off!!!
Moley RUFC said:
look ok, make sure you put a thin coat of copper slip on before using them (then clean any excess off to stop it getting on your discs). also if your taking the wheels on and off alot, its worth getting a stud, so you wind that in to stop the spacer spinning, helping you to put the other bolts in.HTH
doogz said:
Someone on a local car forum I used to use had similar sized spacers on a Saxo before. I crunched the numbers one time, and the moment applied to the hub, required to strip threads of cause a bolt to fail in tension was worrying low. As in, a big pothole or speedbump a bit too fast, and your wheel is coming off.
In my experience, things that work in maths don't work in real life....As for the OP, you're looking for a spacer for one of the biggest modifying scenes in the world. It won't be hard. As has been said, H&R, Eibach, FK, etc etc will make something in your spec and price range.
doogz said:
Someone on a local car forum I used to use had similar sized spacers on a Saxo before. I crunched the numbers one time, and the moment applied to the hub, required to strip threads of cause a bolt to fail in tension was worrying low. As in, a big pothole or speedbump a bit too fast, and your wheel is coming off.
Do those same numbers with the load case being the moment applied to the hub when cornering at 1g (easily done with sticky tyres).Did your calculations apply the moment directly to the bolt or did they overcome the clamp load first? Have a look here http://www.boltscience.com/pages/decomp1.htm
doogz said:
Captain Muppet said:
Do those same numbers with the load case being the moment applied to the hub when cornering at 1g (easily done with sticky tyres).
Did your calculations apply the moment directly to the bolt or did they overcome the clamp load first? Have a look here http://www.boltscience.com/pages/decomp1.htm
If you're considering the bolt in pure tension, a bolt at 6 o'clock with a moment applied equal to the vertical force at the wheel multiplied by the length of the spacer, and consider the bolt pattern tipping around the 12 o'clock 'edge' of the spacer/hub, the clamping force isn't doing you any favours, as you need to consider the tensile stress already present in the bolt/threads from it being torqued up to anywhere between 50-80% yield.Did your calculations apply the moment directly to the bolt or did they overcome the clamp load first? Have a look here http://www.boltscience.com/pages/decomp1.htm
All done. Greased up and torqued. Neither wheel overtook me Herby style either when I stopped so I must have remembered to bolt them on right and worked my maths out right...
Before
After- Wheel is still inside of the arch although this angle makes it look different.
Done
Ready to go to PH Sunday Service at Silverstone!
Before
After- Wheel is still inside of the arch although this angle makes it look different.
Done
Ready to go to PH Sunday Service at Silverstone!
doogz said:
Captain Muppet said:
Do those same numbers with the load case being the moment applied to the hub when cornering at 1g (easily done with sticky tyres).
Did your calculations apply the moment directly to the bolt or did they overcome the clamp load first? Have a look here http://www.boltscience.com/pages/decomp1.htm
If you're considering the bolt in pure tension, a bolt at 6 o'clock with a moment applied equal to the vertical force at the wheel multiplied by the length of the spacer, and consider the bolt pattern tipping around the 12 o'clock 'edge' of the spacer/hub, the clamping force isn't doing you any favours, as you need to consider the tensile stress already present in the bolt/threads from it being torqued up to anywhere between 50-80% yield.Did your calculations apply the moment directly to the bolt or did they overcome the clamp load first? Have a look here http://www.boltscience.com/pages/decomp1.htm
Your load case is worse than reality, which is why the wheels don't fall off production Porches with OEM wheel spacers.
doogz said:
Captain Muppet said:
You won't be increasing the tension in the bolt significantly until you've overcome the clamp load, which isn't just the result of one bolt, but all of them. None of the bolts will be directly loaded until there is a gap between the wheel and hub (or spacer and hub).
Your load case is worse than reality, which is why the wheels don't fall off production Porches with OEM wheel spacers.
But one bolt will see a higher tensile force than the others. Or two of them, depending on the position of the bolt pattern relative to the direction of load application.Your load case is worse than reality, which is why the wheels don't fall off production Porches with OEM wheel spacers.
If you grab the head of a bolt that's torqued up to 70% yield preload, clamping 2 surfaces together, and pull on it, you will be increasing the tensile stress in that bolt.
And Porsche don't run 4*108mm hubs with 6 inch spacers on!
Although, I'll admit, the other thing I am taking into account, is that the clamping force is ignored under a "shock event"
Now, that maybe doesn't translate terribly well, when we consider upwards of 70g as a shock event, but as a general rule, it holds true. I personally haven't verified this from experimental data, but it has been done, and that's what we work with. I believe something similar is also stated in Lloyds Rules. They're shipbuilding rules, but engineering is engineering, if that is shown to be the case, it's just as valid everywhere. The issue/question really is, how quick/large does a load need to be before it's considered a shock load.
Edited by doogz on Tuesday 11th September 13:40
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