Crossmember Bars POLL (cross member cross section)

[nlowe79 at gmail.com (Nate Lowe)]

On 6/23/05, Larry Fry <rocco16@sbcglobal.net> wrote:
> 
> 
> Nate,
>   I don't believe fatigue will be a problem with Eric's bar....simply
> because the bar is not rigid enough to be stressed sufficiently.
> You could stretch a length of 20lb monofilament across the chassis, attach
> it at the same places, and it would not fatigue either.
> 
>  By the way, assumptions and simplifications may be sufficient for most
> listers, but it is not a very accurate way of coming to accurate
> conclusions....as I, myself,  have discovered.  :)
> 
> Did VW go to steel with less strength/thickness in the MkII?  I do not know.
> 
> Larry
> sandiego16v
> 
> 
I know assumptions and simplifications are not sufficient in most
applications, but they're all I have to go with on the bar, other than
the information about what type/thickness of metal that Eric provided.
I didn't mean to give the impression that my basic analysis was all
that should be done, but it's what I could do and what I came up with
was enough to convince me that the bar probably does some good
("probably" or "most likely" etc...).

I still have some doubts, but most have been alleviated. I think the
bar is more rigid than you give it credit for, but this again is based
on assumptions so "I think" is all I can say about that. My other
doubt was with crossmembers that are already cracked. I didn't do any
calculations based on that cause I've never owned a mkII so I don't
really know exactly where these cracks are happening.

Anyway, that's basically how I feel about it. I don't think a real
conclusion is going to be available any time soon, so I'm just going
to hope that the bar works as it's intended for everyone.

Nate