Powder coated wheels - safety issue
Discussion
405dogvan said:
Even if the coating being missing allowed a tiny amount of movement, the time it would take to loosen ALL the nuts is considerable.
Not on a trackday, trust me.405dogvan said:
It's also unlikely that they'd get anything like 'all the way off' before you noticed the vibration - and it's inconceivable that you'd continue to drive as the nuts fell off.
When I checked the wheel, one nut was nearly out, the other four were not much more than hand tight.Since then I check the nuts several times throughout the track day.
This happened to me too at Bedford track day recently, powdercoated rims got really hot on the front (brakes were smoking after a few laps) and both wheels had to be retightened (loose and rattling !) on the way home on the road, despite having been torqued a couple of times at normal temps to 85lbs.
I could say I drove the wheels right off it on the track !
I could say I drove the wheels right off it on the track !
Local tyre place advised me of the same after having some freshly powder coated wheels fitted to my car. Said that they really need to be checked and rechecked a good few times after having them fitted for the same reason as described by the OP and several other folks in this thread. I brushed it off as scaremongering but looks like they were right!
405dogvan said:
Even if the coating being missing allowed a tiny amount of movement, the time it would take to loosen ALL the nuts is considerable.
It's also unlikely that they'd get anything like 'all the way off' before you noticed the vibration - and it's inconceivable that you'd continue to drive as the nuts fell off.
The actual WHEEL coming off is a bit like letting a small crack in the wall become 'your house falling down' - you'd notice something...
Thank God for a reasoned response.It's also unlikely that they'd get anything like 'all the way off' before you noticed the vibration - and it's inconceivable that you'd continue to drive as the nuts fell off.
The actual WHEEL coming off is a bit like letting a small crack in the wall become 'your house falling down' - you'd notice something...
9mm said:
Thank God for a reasoned response.
Just a shame that it is completely wrong. OP is correct in what he has said and is being very helpful in pointing out something that most, like your good self, clearly don't known.
The one thing that he didn't mention is, on a track day, do not torque the bolts to their normal full setting they once they are hot. If you do, when the cool they will stretch and eventually fail.
PAN1C said:
9mm said:
Thank God for a reasoned response.
Just a shame that it is completely wrong. OP is correct in what he has said and is being very helpful in pointing out something that most, like your good self, clearly don't known.
The one thing that he didn't mention is, on a track day, do not torque the bolts to their normal full setting they once they are hot. If you do, when the cool they will stretch and eventually fail.
9mm said:
PAN1C said:
9mm said:
Thank God for a reasoned response.
Just a shame that it is completely wrong. OP is correct in what he has said and is being very helpful in pointing out something that most, like your good self, clearly don't known.
The one thing that he didn't mention is, on a track day, do not torque the bolts to their normal full setting they once they are hot. If you do, when the cool they will stretch and eventually fail.
mwstewart said:
Whilst the practise above isn't correct, I disagree that it is a safety issue. The action of tightening the bolts will score the coat off of the bolt chamfers, and the coat on the mating face will at worst cause (very minor) wheel balancing issues.
This is wrong.Sorry for being harsh but it has to be put very bluntly on this issue as it is a safety issue.
You NEED to clean out the wheel bolt recesses, centre bore and hub face. When testing with freshly power coated wheels that did not have this done you end up having to re torque the wheel nuts every ten laps. There are numerous people I've spoken to who have experienced this issue.
Losing a wheel is entirely possible.
rigga said:
Monty Python said:
Isn't the simple solution just to simply re-torque the bolts after a short period of use?
Which is the normal advice when a wheel is removed for any reason ...mwstewart said:
Whilst the practise above isn't correct, I disagree that it is a safety issue. The action of tightening the bolts will score the coat off of the bolt chamfers, and the coat on the mating face will at worst cause (very minor) wheel balancing issues.
It most definatly IS a safety issue. Powder coating can be many times the thickness of paint and the mating surfaces should be bare.Look at any new alloy wheel and the mating surfaces will not be coated. New manufacture steel wheels will come with mating surfaces painted, however, factory paint thickness is minimal and wont be an issue. During any after market refinishing mating surfaces should always be masked off. The truck industry is particularly strict on these issues.. PAN1C said:
The one thing that he didn't mention is, on a track day, do not torque the bolts to their normal full setting they once they are hot. If you do, when the cool they will stretch and eventually fail.
To echo this point hot bolts will appear loose when a torque wrench is applied even if the bolt is at design torque. It is good practice to never torque a hot bolt ever unless the bolt is "lifed" such that your going to discard it long before thermal stress fractures become an issue. Also remember to tighten in correct pattern (opposites working clockwise).405dogvan said:
Even if the coating being missing allowed a tiny amount of movement, the time it would take to loosen ALL the nuts is considerable.
It's also unlikely that they'd get anything like 'all the way off' before you noticed the vibration - and it's inconceivable that you'd continue to drive as the nuts fell off.
The actual WHEEL coming off is a bit like letting a small crack in the wall become 'your house falling down' - you'd notice something...
I had a wheel fall off once. It was about eight corners from "what's that noise?" to the wheel falling off. I was heading for the pits at walking pace when it came off.It's also unlikely that they'd get anything like 'all the way off' before you noticed the vibration - and it's inconceivable that you'd continue to drive as the nuts fell off.
The actual WHEEL coming off is a bit like letting a small crack in the wall become 'your house falling down' - you'd notice something...
Captain Muppet said:
I had a wheel fall off once. It was about eight corners from "what's that noise?" to the wheel falling off. I was heading for the pits at walking pace when it came off.
Two corners to get from AOK to that ^^^
That's the third lap of the day, with the nuts checked just before going out.
I have seen a good few wheels come off at track days before so don't think it never happens.
The heat tht goes through the hub and to the alloy intense, so much so that we had to wait for the wheel to cool down before swapping the alloy to the rear.
But hey, I sure hope the know-it-alls in here never have the misfortune of wheel nuts coming loose.
The heat tht goes through the hub and to the alloy intense, so much so that we had to wait for the wheel to cool down before swapping the alloy to the rear.
But hey, I sure hope the know-it-alls in here never have the misfortune of wheel nuts coming loose.
22rgt B Squadron said:
It most definatly IS a safety issue. Powder coating can be many times the thickness of paint and the mating surfaces should be bare.Look at any new alloy wheel and the mating surfaces will not be coated. New manufacture steel wheels will come with mating surfaces painted, however, factory paint thickness is minimal and wont be an issue. During any after market refinishing mating surfaces should always be masked off. The truck industry is particularly strict on these issues..
Ex Special Air Service . 22 regiment 'B' Squadron.HAHO (high altitude parachutist instructor)
Covert sniper insertion specialist.
ging84 said:
when i painted my wheels i got a reasonable amount of paint on the back
after a good hard run this did indeed soften on one of the wheels and cause the wheel bolts to be slightly loose
after a couple of days of thinking i had a drive shaft on it's way out i was spared any expense by adding half a turn to each wheel bolt.
hardly anyone died because of this incident
As he says!after a good hard run this did indeed soften on one of the wheels and cause the wheel bolts to be slightly loose
after a couple of days of thinking i had a drive shaft on it's way out i was spared any expense by adding half a turn to each wheel bolt.
hardly anyone died because of this incident
Any coating will soften or fret over time. You just need to retorque. Simples. Had it recently on an ARB I'd painted. "Why are the drop links rattling"? Ah, paint......
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