Using rebar as DIY sway bar?

[Son of Marty]

1 hour ago, k3vin said:

told you how important this start up was to help with the lawyer fees from the home made baby car seat idea 2 years ago. 

Who would have guessed that a baby didn't need a ejection seat.

[cda951]

4 hours ago, autokunst said:

Not a structural engineer, but know enough to be able to observe that rebar is made from mild steel.  Typically grade 40 or grade 60.  This relates to tensile strength, which is what reinforced concrete doesn't have.  Sway bars are typically made from a chromium molybdenum steel allow (chrome moly) - often 4130 or 4340 alloys.  Sway bars do not need tensile strength.  Rather, they rely almost entirely on stiffness related to rotational (or torsional) resistance.  COMPLETELY different characteristics.  

 

I applaud "upcycling" things for useful purposes.  But this does not sound like a functional use.  I don't know that it would be "unsafe".  Just not functional for the intended purpose in my opinion. 

 

It certainly could be "unsafe" in the event of a front sway bar exhibiting fatigue failure mid corner, the sudden change in the rate of weight transfer between the front and rear could cause the rear end to snap oversteer. I know this because I've lived it! In the distant past I foolishly applied overly large sway bars with stock springs on my Porsche 944 Turbo track car (to comply with the regulations of the specific "improved" class I was running in POC at the time), and the 944 has an afterthought front sway bar design with long center brackets hanging down to allow the sway bar to fit under the engine.

 

If the brackets got a slight bend due to contact (ground clearance was an issue), then any kind of side load would cause either the thicker aftermarket brackets to fatigue and fail or the mounting points would tear out of the frame rails! Luckily I caught the slide when it happened.

 

I weld reinforced both sides and moved up a few classes to allow proper coilovers with stiffer springs and never had another issue---I learned my lesson well, sway bars should be fine-tuning aids for handling balance, not the primary means of quelling body roll.

 

I don't know the details of the proposed rebar sway bar setup, but it's bad news bears from the beginning. I'm neither an engineer nor a lawyer, but I do know that any hint of the remotest possibility of failure of a suspension component is fodder for lawyers, no matter the method of failure. I echo the notion that "upcycling" only makes sense if it's applied in an intelligent manner.

Edited January 24, 2023 by cda951

[d.hitchcock]

This thread: 10/10. Will check back for updated giggles.

[tzei]

A willow branch might do as well. + 100% biodegradable which is good thing these days. It’s pretty stiff you know.

[tech71]

3 hours ago, tzei said:

A willow branch might do as well. + 100% biodegradable which is good thing these days. It’s pretty stiff you know.

Better yet, a length of stout English Yew, its springy

Edited January 24, 2023 by tech71

[tzei]

Oh yeah! Different tracks needs different set ups.

[PapaG]

I've both represented and sued most of the major players in the auto industry in hundreds of products liability cases over the last 38 years, many of which dealt with suspension related failures. This has to be a joke, no sane person would do this and try and turn it into a business.

[John_in_VA]

In the 80s some race shops welded a bar (NOT rebar!) onto the bottom of the existing front sway bar to beef it up.

[TobyB]

https://www.youtube.com/watch?v=haPvuhznuyI

 

Not sure if srs...

 

t

 

[williamggruff]

29 minutes ago, John_in_VA said:

In the 80s some race shops welded a bar (NOT rebar!) onto the bottom of the existing front sway bar to beef it up.

I can confirm this. The 77 e21 I bought from Bill Riblett had a beefy front sway bar that had the center section of another beefy front sway bar stitch welded to the underside: 6-inch lengths of weld separated by 2-inch spaces. Heavy? Yes. Functional? 😂 

 

 

[k3vin]

3 hours ago, TobyB said:

https://www.youtube.com/watch?v=haPvuhznuyI

 

Not sure if srs...

 

t

 

It’s was a joke but I think it may have missed 

[Gil. H.]

On 1/23/2023 at 7:51 PM, Devilish_02 said:

Current leader for LOL award of the thread.