Why is a swaybar shaped the way it is? Burkhart Chassis has a swaybar this is rectangular. Every other one I've seen has that same shape, like the BMR and Strano bars, for example. I thought the rear may have this shaped to go around the differential, but that doesn't explain why the front also has this shape. Why not straight, like a PHB? Why not rectangular, like Burkhart Chassis' bar?

 

Sway bars are a torsion spring, meaning they work by a twisting motion. They need to be able to move as they are attached to your wheels, but their torsion spring force reduces body roll. Therefore the shape is designed to allow the bar to twist as well as avoid other car components. Torque arms are designed to have no bending motion.

 

Cool...follow up question: Strano makes hollow sway bars. I think it's because material in the middle is not needed when twisting force is applied. But if you take a hollow stick of aluminum(something you can bend with your hands) and twist it you can permanently distort it. If you take that same stick of aluminum and make it solid, somehow, I seriously doubt you could distort it. How then is hollow just as strong as solid??

 

stick of aluminuym or rod of aluminum?
the boxed peice does not have the torsional strenth a tube would have
in a tube or rod the inner part contributes very little to torsional strength and removing it serves a better purpose, weight reduction

 

Aluminum is not a spring material; springs are usually made from mild steel. But the diameter is what contributes most to torsion.

 

Ya'll missed the point on the aluminum rod. i only chose aluminum because a steel rod(hollow or solid) you wouldn't be able to bend by hand. I was trying to use an example where you could tell the difference by hand. Anyway, I guess I'll just have to take it as it is: torsion forces are effected by the diameter of a tube and not by the material or amount of material inside.

 

thats why i said, aluminum or not, if its square tubing i wont have the torsional strength as round tubing and in round tubing the inner material has a negligible impact or torsional strength and would suit you better by not being there for weight reduction

 

The bend in the center of the front bar is to fit around the crank pulley
To compare the stiffness of hollow vs solid swaybars, you can figure the stiffness of a hollow tube if you know the wall thickness. The stiffness if a solid bar is the diameter to the 4th power (say 35x35x35x35) and for a hollow tube its the OD minus the ID (say 35x35x35x35 minus 30x30x30x30 if the tube had 2.5 mm walls). Of course this assumes identical dimensions which is unlikely but it gets you in the ballpark. You will find that a solid bar has a slight stiffness advantage but a significant weight disadvantage.