Quote:
Originally Posted by JCL
And some technical inspectors won't allow spacers due to the safety risks, particularly on front wheels with their higher braking loads.
I would agree that bolt-on adaptors are safer, but I don't think they are as safe as having no spacer. You have introduced an additional failure point, as well as changing the load on the wheel bearing, and suspension components. That has to count for something.
I think that loose spacers are far less safe. It doesn't matter if the lugs are a higher strength steel, unless you calculate both the bending moment and the fatigue limit and make sure both are still reasonable. One calculation I saw showed that a 1/8" spacer (3 mm) reduced the safety factor by two. I consider that a significant reduction in safety.
Good previous discussion here, with my link to another thread in the GT40 forum. http://www.xoutpost.com/bmw-sav-foru...l-spacers.html |
I completely agree with your assessment of slip-ons (loose), as the bending moment will affect the loading on the bolts more.
However, it's difficult to get on board with the idea that bolt-ons would decrease an MTBF by a factor of two. Follow this thought process:
1) The only thing you are introducing is a slab of aluminum. Granted, you are adding 5 more bolts to that wheel hub, so technically, there would be your MTBF reduction by 2, but that's subjective much like many reliability calculation methods.
2) The idea that you are imposing more load on the axle and hub are nearly moot due to the nature of differing wheels themselves. Obviously the loading on the hub is different with the sport 20's vs. the stock 18's. The 18's have a higher offset and are tucked in more. To think that a safety factor is not used would be crazy.
3) I know the right way to build a widebody track car would be to replace the axle, hubs, and associated suspension arms, but not everyone does this. The cheaper and more popular way to achieve the stance is to purchase very low (in the negatives) offset wheels, which are effectively much further off the hub than what you'd get with spacers.
What I'm trying to get at is that if anyone has a cause for alarm for even a 1" (25mm) spacer on their wheels is ludicrous in my book. But if it does make one feel uneasy, then simply don't buy them.
