wobble bolts

[Shaun1982]

So come on then. What's people's opinions on these? Just had to Google them & the pistonheads forum users generally don't think they are safe.
What you saying?

[Dubvrs]

I have run them before with no issues.

I would choose them over PCD adapters any day.

[Shaun1982]

I don't understand them if I'm honest but on Ph people's issue seems to be something like the wheel can move about as the thread is smaller than the hole,something like that

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[Dubvrs]

I don't see how it can move? If you have the correct spigot ring in the wheel it will be centralised.

[Shaun1982]

It's also tightened up against the hub so surely shouldn't move. What did make me laugh though was that someone put "I'm sure a Volkswagen driver will come along & say it's fine as there's no problems yet " lol

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[chelspeed]

As an engineer my immediate thought is that it's a bodge and shouldn't be used anywhere where a failure would be bad. Wheels bolts certainly come into this category.

But then I start to look at it in detail. To allow the washer to move to the required location does the diameter of the bolt need to be reduced? If so then you've lost some shear strength in the bolts. But if the movement comes just from an increased size hole in the middle of the washer and there's still enough washer left to centralise in the wheel and apply the required force from bolt head to wheel (ie wobble a mm or so but not much more) then I'm struggling to say why there's a problem.

I've run wheels without spigot rings in the past (previous cars) when I had custom disc bells made which couldn't have spigot rings incorporated, just relying on clamping force and wheel bolts for location. Worked fine. My thoughts were that the spigot rings provide location where the wheels are trying to move, suspension loading, static due to the weight. They weren't providing any help in resisting the wheel rotating, acceleration and braking, the wheel would just turn on the spigot ring. I think under braking would be the worst loading and the wheel bolts in shear are quite capable of passing this force from hub to wheel so the spigot ring is redundant. But others disagreed. I won the argument in the end because I ran like it for 2 years and nothing broke.

But I certainly wouldn't use wobble bolts without a decent strong spigot ring ie straight from hub to wheel casting, no spacers or adaptors.

In balance I don't think I could bring myself to use wobble bolts. But I can't say exactly why. Just offends my engineering judgement I think.

[Shaun1982]

They baffled me lol. Thought I'd look as I was looking at those bbs reps on here that he had with spacer & wobble bolts.

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