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Discussion Starter · #1 ·
Hello club B5er's;

I am thinking of making my own rear anti-sway bar. I cannot divulge secrets of design quite yet, so I am looking into feedback and if you are intersted in one maybe...

If you have perspective on legalaties, or just "for off-road use only" disclaimers etc...

TIA,

Cheers,

Malcolm
 

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If you can make a 23mm rear bar for the 4MO, there would be plenty if interest. The rear bar on a fwd is pretty simple depending on the mounts.
 

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The design of any aftermarket rear sway bar for the B5 is not patented to my knowledge, so design away.

I think the P&P Motorsports bar I have bolted inside my rear axle beam is roughly 1 3/8" OD tubing (not bar...gotta keep the weight down) with the ends cap-welded, powder coated black, with four M8 mounting bolts (two at each end spaced 4 inches apart).

Should be able to do one for less than $200...which seems to be the going rate these days.
 

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Discussion Starter · #5 ·
WOuld any-one like one if I do a production run??

Please let me know so I can work out costing with my Fabricator...

Cheers,

Malcolm
 

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Discussion Starter · #7 ·
I'm thinking of aluminum...
 

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Yeah, i think most interest would be in a 4mo bar.
The FWD cars are served by a number of very good options covering a lot of prices.
 

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Aluminum can't withstand repititious bending cycles. It WILL crack. The grain structure of aluminum doesn't allow these kinds of stresses.
 

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a sway bar is a spring. there's a reason why steel is used for 99% of springs.
@Malcolm S. Freeman :start looking for the best suitable steel (aloy) and as I said,forget aluminum.Look for steel used for springs.Go through American ,British and German standards for steel aloys and compare characteristics and specifications.When u conclude ,post them here for more feedback.
My 2c.
 

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Discussion Starter · #15 ·
Just wondering how much flex is needed in an internal beam stiffener? If the objective is to make the beam stiffer, wouldn't aluminum be the best choice?

Keep the thoughts coming....

Cheers,

Malcolm
 

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No. It'll fatigue. Why the need to make your own? There's already plenty of options out there.
 

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No. It'll fatigue. Why the need to make your own? There's already plenty of options out there.
u need to make your own for the following reasons:
1.u might end up with a better product,sometimes cheeper too
2.the satisfaction of DIY
3.u may sell few and recover your production costs
etc
 

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Wow. Malcolm, if you need to be convinced to make it out of steel, then I don't really think you ought to be making them. Really, I'm not trying to bust your chops, just being realistic.
 

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Yes, its about bikes, but the principles are exacly the same (Basically a tube of welded metal)
http://spokesmanbicycles.com/page.cfm?PageID=328
Most notable:
Fatigue Strength
Guess what? This is another important property to consider but, once again, not by itself. Fatigue failure occurs by applying cyclic stress of a maximum value less than the static tensile strength of the material ... until your specimen fails. This can be a cool test, because the alternating stress mimics vibrations and impacts that happen when you ride your bicycle down the long and winding road.

The fatigue strength itself is a measure of the stress at which a material fails after a specific number of cycles. What's tough though, is designing the proper test. Again, a bicycle is a complex puzzle to consider. There is no standard test for fatigue. Another kink is that fatigue tests are done by cyclic loading of similar stress, whereas the loads you apply to your bicycle parts are uniform.
Ferrous alloys (a.k.a. steel) and titanium have a threshold below which a repeating load may be applied an infinite number of times without causing failure. This is called the fatigue limit, or endurance limit. Aluminum and magnesium don't exhibit an endurance limit, meaning that even with a miniscule load, they will eventually fail after enough load cycles.
Technically you could make a material out of TI, but given the use you wouldn't ave much if any weight (Ti needs more martial to be as stiff as an amunt of steel), and cost would skyrocket.
 

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Discussion Starter · #20 ·
In a nutshell, I was thinking of the bar portion to be aluminum, however, the through-bolts would first pass through a steel plate with matching holes increasing the strength in the welded area. Instead of washers, there would be two plates that sandwhich the beam and the aluminum bar would be re-inforced at the welded area. The spacing on the through-holes would be wider than say the O-bar.
 
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