Sway Bar Solid or Hollow which is better? - Honda Prelude Forum

LuDeS · 01-17-2002, 08:24 AM

I've been having this debate with my friend as to whether a sway bar being hollow is better than being solid... My friend swears that hollow is better because it saves weight... he has the neuspeed sway bar for his audi a4 and he says since its hollow its better...
Also is the Sus Tech rear sway bar hollow or solid?

HRC · 01-17-2002, 10:38 AM

solid, my neuspeed bar is.

solid is better.

Randy0002 · 01-17-2002, 11:53 AM

In most cases hollow tubing (like a sway or strut bar) is lighter, stiffer, and stronger. Thats just what I've noticed, I'd assume it would hold true w/ sway bars as well.

LuDeS · 01-17-2002, 12:02 PM

Quote:

Originally posted by Randy0002
In most cases hollow tubing (like a sway or strut bar) is lighter, stiffer, and stronger. Thats just what I've noticed, I'd assume it would hold true w/ sway bars as well.

hmm i guess my friend is right

Two-Five Boy · 01-17-2002, 01:22 PM

Quote:

Originally posted by Randy0002
In most cases hollow tubing (like a sway or strut bar) is lighter, stiffer, and stronger. Thats just what I've noticed, I'd assume it would hold true w/ sway bars as well.

Sorry but I have to disagree!!!

Pls explain why IYO a hollow bar would be stiffer and stronger than a solid one?

Ludes, the ST bar is solid!

Mz3silver · 01-17-2002, 01:30 PM

Hollow bar is stronger....and is only true on a straight bar

.... having said that, everything is relative --> size of bar vs. the size of the 'hole' through the center - too small not effective, too big, weak

Anyway, if you were to bend two bars, one hollow and one solid, the solid one will bend easier....

HRC · 01-17-2002, 01:30 PM

2-5, people will believe what they want too, don't sweat it, no use in

Two-Five Boy · 01-17-2002, 01:53 PM

Quote:

Originally posted by HRC
2-5, people will believe what they want too, don't sweat it, no use in

Don't worry, not trying to argue!

Just want to hear from his perspective how hollow is stronger than solid?

PreludeVTEC01 · 01-17-2002, 01:54 PM

hollow stronger than soild.... i am not seeing it...?

HRC · 01-17-2002, 01:58 PM

Quote:

Originally posted by Two-Five Boy

Don't worry, not trying to argue!

Just want to hear from his perspective how hollow is stronger than solid?

i quess neuspeed and st really dropped the ball when it came to designing sway-bars to be solid pieces! lol...but really, i was so surprised when i changed the swaybar, how light the OEM one is compared to my neuspeed...superflea's st bar was also heavy compared to stock...

LuDeS · 01-17-2002, 02:20 PM

Quote:

Originally posted by HRC

i quess neuspeed and st really dropped the ball when it came to designing sway-bars to be solid pieces! lol...but really, i was so surprised when i changed the swaybar, how light the OEM one is compared to my neuspeed...superflea's st bar was also heavy compared to stock...

actually neuspeed didnt really drop the ball like ST at least for other applications because my friend got his rear sway bar from neuspeed for his audi a4 and its hollow...

Dynamic EBP · 01-17-2002, 03:55 PM

why would you want a lighter sway bar... maybe if hollow is stronger, but if its for weight reduction...cmon

Darth Luder · 01-18-2002, 06:42 AM

A hollow bar is not stronger than a solid bar of the same material and manufacturing processes. Hollow bars are only used to save weight. Now, in torsion, a hollow shaft is sometimes used in place of a solid shaft because 90-some percent of the load is carried on the outside fibers of the shaft. However, in axial loading, this is not the case. If the bar were to fail, it would in shear, ie snap. The cross section would be at a 45 degree angle. One of the parameters in calculating the shear stress a bar can take is the cross sectional area of where it will fail. Therefore, can you see that the solid bar has more cross sectional area than a tube would? Even if the bar was more brittle and stiff than ductile and fails at a 90 degree angle rather than 45, then it fails in tensile stress and still has more cross sectional area than a tube.

Now that said, you can have a hollow tube stronger than a solid bar only if the solid bar is made of a material that has a lower resiliance factor, tensile and shear strength, is way more brittle than the tube, or just a cheaper material like a cast material or one that is not as pure.

Mz3silver · 01-18-2002, 07:48 AM

I stand corrected.....

LuDeS · 01-18-2002, 08:33 AM

Quote:

Originally posted by Darth Luder
A hollow bar is not stronger than a solid bar of the same material and manufacturing processes. Hollow bars are only used to save weight. Now, in torsion, a hollow shaft is sometimes used in place of a solid shaft because 90-some percent of the load is carried on the outside fibers of the shaft. However, in axial loading, this is not the case. If the bar were to fail, it would in shear, ie snap. The cross section would be at a 45 degree angle. One of the parameters in calculating the shear stress a bar can take is the cross sectional area of where it will fail. Therefore, can you see that the solid bar has more cross sectional area than a tube would? Even if the bar was more brittle and stiff than ductile and fails at a 90 degree angle rather than 45, then it fails in tensile stress and still has more cross sectional area than a tube.

Now that said, you can have a hollow tube stronger than a solid bar only if the solid bar is made of a material that has a lower resiliance factor, tensile and shear strength, is way more brittle than the tube, or just a cheaper material like a cast material or one that is not as pure.

EVERYONE BOW TO THE ALL KNOWING DARTH

71dsp · 01-18-2002, 09:30 AM

It is interesting to note that most "real" race sway bars are the torsion bar type. i.e. it is made of three pieces; the two lever arms, and the torsion bar. The torsion bar is usually hollow, and the arms are usually solid. This allows adjustment not only in the length of the lever arm, but the torsion bar can be swapped out with bars that have different wall thicknesses to adjust the stiffness of the bar.

It's not just weight savings that people use hollow bars, it's that the stiffness of the bar depends on the thickness of the wall, so it allows for some fine tuning.

Perhaps Neuspeed didn't use hollow tubing on the Prelude bars as a matter of cost (since there are quite a few bends in the bar), and hollow tubing might compromise the strength of the lever arms.

Darth Luder · 01-18-2002, 10:27 AM

Quote:

Originally posted by 71dsp
It is interesting to note that most "real" race sway bars are the torsion bar type. i.e. it is made of three pieces; the two lever arms, and the torsion bar. The torsion bar is usually hollow, and the arms are usually solid. This allows adjustment not only in the length of the lever arm, but the torsion bar can be swapped out with bars that have different wall thicknesses to adjust the stiffness of the bar.

It's not just weight savings that people use hollow bars, it's that the stiffness of the bar depends on the thickness of the wall, so it allows for some fine tuning.

Perhaps Neuspeed didn't use hollow tubing on the Prelude bars as a matter of cost (since there are quite a few bends in the bar), and hollow tubing might compromise the strength of the lever arms.

Well, in torsion, most of the load is on the outside fibers so in that case it would make sense to have a hollow bar at that point, solid endlinks for tensile strength, and save some weight on the torsion bar part since the middle of the bar is mostly useless. The thicker the wall is though the more load you can carry in that wall as you increase to the maximum solid bar. But the gains of going down to a solid mass start droping off. So you can get the strength you need and save some weight by making it hollow, for the torsion part.

71dsp · 01-18-2002, 11:40 AM

Quote:

Originally posted by Darth Luder
Well, in torsion, most of the load is on the outside fibers so in that case it would make sense to have a hollow bar at that point, solid endlinks for tensile strength, and save some weight on the torsion bar part since the middle of the bar is mostly useless. The thicker the wall is though the more load you can carry in that wall as you increase to the maximum solid bar. But the gains of going down to a solid mass start droping off. So you can get the strength you need and save some weight by making it hollow, for the torsion part.

That's what I was saying, thanks for saying it again.

Darth Luder · 01-18-2002, 03:36 PM

Quote:

Originally posted by 71dsp

That's what I was saying, thanks for saying it again.

Well, sort of, just explained a few things. Youre welcome.

Mostly though, there is more than one way to skin a cat.