Peeps,

If I were to build another car, but this time a nice light car, say with a m/c engine in it (let's just call it a bec shall we, could I get away with 3/4" rhs all round.

I'd, of course, be going the live axle, 13" wheel route this time with all panelling riveted in place for rigidity.

ATB

Simon

If you're after weight saving then I would have thought 1"/25mm dia round tube would be a better/safer bet.

If using 3/4" RHS wouldn't you need to up the wall thickness to compensate for strength? Thereby losing any weight saving over thinner walled 1" RHS?

Reducing section size not a good idea ---- due to buckling on members under compressive load.
Better to go for thinner wall thickness -- 1.2 mm

[Edited on 23/9/07 by britishtrident]

id do as bt says, and use 19mm round tubes for triangulation. If you are building a low weight bec you can remove an awful lot from the locost chassis, afterall it was designed to fit a car engine. Mine will be about 18" shorter.