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Wheel Spacers ?

Alloy wheels and tyre discussion
AveZ4coop
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WHEEL SPACERS?

Post by AveZ4coop » Fri Jun 25, 2021 1:27 pm

sars wrote: Fri Jun 25, 2021 12:27 pm Definitely, because the primary forces acting on the bolt are radial not axial, thus the longer the bolt the lower the radial force the bolt can withstand. Think of the wheel bolt as a lever, the bolt is gripped at one end and a force applied uniformly and perpendicular to it along the length, the longer the bolt the greater the torque. Bolt stress calculations are fairly complex with many variables, so it's not linear, if you double the bolt length you will more than halve the maximum permissible radial load.

A hub bolted spacer is more expensive to manufacture as there are more operations to perform so they only do it when they have to, there is a DIN standard and a TÜV approval thereto that governs the design of wheel spacers so I don't imagine that fitting bolts through a 12.0mm spacer is dangerous if done correctly.

I would always go with bolt to hub if I really had to use spacers. I know that wheel design is a personal choice and we all have different tastes, but I would rather choose an alloy that had the correct offset than one that was more aesthetically pleasing and have to add spacers as there will always be concentricity issues due to tolerances.
If the spacers are hubcentric, the the load on the bolt is purely axial ? If they are not hubcentric, I would be afraid!
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sars
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WHEEL SPACERS?

Post by sars » Fri Jun 25, 2021 1:55 pm

You have five bolts, the hub and the clamping force between the contact surfaces and the radial load iis distributed across each of them. To simplify, imagine those five bolts and hub laid out equally distanced in a straight line and they all touch and support a beam, is the weight of the beam not held by all the contact points?
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Gone 2017 Iridium SL400, 2015 435d xDrive Convertible, 2012 E350 CDi Convertible, 2010 DSB Z4 sdrive30i, 2008 Audi A4 Cabriolet, 2006 Phoenix Yellow Z4 2.5Si, 2003 Saab 9-3 Convertible

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