quote:

Originally posted by egregore:
Some of the things that go on in the automotive business, and tires in particular, are dangerous. Look up, for example, the outer ring of a split rim blowing off. (Thankfully you don't see these much any more.) Those have been known to cut people in half.

I had a shop teacher in the 80s who face was all scared from a split ring blowing up on him.

quote:

Originally posted by 71 TRUCK:

quote:

Originally posted by egregore:
Some of the things that go on in the automotive business, and tires in particular, are dangerous. Look up, for example, the outer ring of a split rim blowing off. (Thankfully you don't see these much any more.) Those have been known to cut people in half.

I had a shop teacher in the 80s who face was all scared from a split ring blowing up on him.

I worked at a tire store when they were popular and did many split rims before inflation cages were used. I was good at it and liked them and they scared me just a bit, I respected them. I always wanted a truck that I could change tires or fix flats that easily, as long as tires last these days, forget it.

As with many things today, it is the degree that you carry these thing to that matters. With tire stretching, a slight stretch can enhance tire performance and vehicle handling. Manufacturers generally recommend a maximum rim with that is approximately equal to the tread width. This allows for some compliance for an acceptable ride and the tire overhang provides some protection for your wheels. However, in the performance arena, it is generally accepted that a tire that is on a wheel the same overall width will give the optimal performance. Thus you have a "square" profile whereas the wheel width with equals the tire width. This "square" profile minimizes the flexing and squirming that can erode a car's handling and grip. In your example of a 215mm width tire, you would want to mount it on a wheel of approximately 8.5 inches. There are drawbacks however. Since your wheel and tire are the same width you are more prone to scratch or scuff the wheel since there is now no protection for the wheel. Also, your ride goes to hell...since you primary objective is to add stiffness to the tire for better response and handling the ride suffers from the additional stiffness. It is one of those things where you have to decide which you want.

Now...on the question of why someone would mount a tire on a wheel that is grossly too wide? This is just the style of today. The "hellaflush" look is all the rage and the overly stretched look is part of that. Like the video indicates, by using a narrow tire on a wide wheel...and additionally utilizing radical negative camber settings you can bring out the tire and wheel assembly to the very edge of the fenders and lower the car more than you would normally be able to. When the car hits a bump the wheel with the stretched tires and negative camber tend to tuck into the fender rather that crashing down on top of it.