Need help with chassis information

[homebrew]

Hi all it has been along time since I posted last. Does anyone know the tube dimensions i.e. tube diameter and wall thickness for the Caterham, Birkin and Westfield? Just looking for the main tube dimensions.

 

A little background to this question. I built a Locost that I now mainly use as a track day car. This year I ran into an overzealous official with a local race sanctioning body who has denied me from particpating in track days put on by his organization because he feels my car is not safe enough to be on the track. He questions not only rollbar height, material thickness and attaching points and methods but also the chassis materials, tube diameter and thickness. The tech steward understands the problems this guy has created and has suggested if I can come up with engineering data it might shut this twit down. So If I can prove the same materials were used in a Caterham it might help my case.

 

Any help would be appreciated.

 

Jim

[SkinnyG]

There are copies of Lotus 7 chassis drawings at http://www.diyse7ens.com. Originals used mainly 1" and 3/4" round tube, with a few pieces of 1", 3/4" and 5/8" square tube. All 18ga.

 

The locost is over-built compared to an original (more 1" tube, and 16ga), but (probably) less triangulated than a modern Caterham.

 

I can see their concern, as according to most GCR's the Caterham roll bar (and chassis) is pretty insubstantial, especially in the roll bar mounting. If Caterhams are allowed at your track, the locost should be. They're just trying to cover their ass and protect yours.