Does anyone know why tubes TR1,2,3,4 are made of tubular steel instead of 25mm box section? I can't see much that's gained from using this. I suppose it's possible that with TR1+2 it's slightly easier to fit the aluminium sheeting- but I'd be a little surprised.

Thanks,
James

I think it's maybe because it's a tight angle and the square corners may look untidy where it joins the upper and lower members. Personally I'm using the leftover 19mm rhs from the trasnmission tunnel.

Dunc