Roll Center and Spacer Question

[Thoughtful_One]

I was cruising through a few sites when I stumbled upon Heavy Throttle's site. On the homepage, they were advertising wheel spacers, since I was curious I entered and found some potentially wrong information. For those of you with suspension knowledge, read this and tell me what you think:

"...wheel spacers move the wheel out from the hub, effectively widening the stance of the vehicle and lowering its roll center. This simple modification increases lateral stability, which in turn provides improved handling, greater safety and of course, the sleek style you've been looking for."

I agree that the spacers widen the stance, but lowering the roll center is not true for the spacers. The roll center is dictated by suspension geometry. Putting on a 5 MM spacer or even a 150 MM spacer should not change the center.

I'm debating about getting spacers for my base Kouki S14 wheels that have a 40MM offset. There are some things holding me back though. First, they're Al. With there low elastic modulus, I would l think that the cornering forces developed after several "spirited" runs would cause the Al to deform, putting some slack between the wheel and the rotor. Plus, I would think that it isn't the best for wheel bearings. I like the wheels, but not the offset.

Also, I have a quick question. Say you have two cars which are the same. One has stock springs, and the other has springs of the same spring constant but lowers the car by say 2". Won't the lower car be more susceptible to body roll since the roll center will be lower, being farther from the CG? If the distance is increased, the inertial moment of the CG from the roll center through a turn would be greater. I've read only a few things on suspension so I may not have a complete understanding of what is happening.

Does anybody have an idea about where the CG is on a stock S13/S14 with driver? I'm guessing on the top of the seat.

[Kenny_D]

I don't think spacers are going to bend your rims, they've lasted this long. And it doesn't matter how low it is, with stock spring rates it's gonna roll like a beast.

[Thoughtful_One]

I never said rims would be bent.

That's not the point of the question I asked.

[whiterps13]

As far as your question on spacers, the answer is no. Spacers have absolutely no effect on handling or suspension geometry. Some companies just throw out bull**** information to persuade ricers to buy their products; its that simple. Spacers will increase wear on wheel bearings since they effectively move the wheel further away from the hub. In the same instance, wheels with super aggressive widths and extremely low (think negative) offsets will cause just as much harm to your wheel bearings. Will you notice a differance? Probably not. Spacers are purely asthetic in my book.