A while ago I recall seeing a comment on ApexSpeed that said all the frame tubes on the cockpit sides must be a minimum of 1" x 0.080". I remember it referred to a section of the rules other than where you would normally go for that information, but now I can't find it. As I read the GCR, all tubes that connect the main roll hoop forward braces to both the front roll hoop and the main floor rails must be at least that size, but other tubes are not specified. Here' s the applicable section of the GCR:
"C. Roll Cage Bracing
1. The main hoop must have 2 forward braces extending from the
hoop and attached to the frame, monocoque, or front hoop.
Braces must be attached as near as possible to the top of the
hoop but must not be more than 6 inches below the top and
at an included angle of at least 30 degrees. If these braces do
not extend to the front hoop, an additional brace or gusset (14
gauge - .078” minimum thickness) must be installed between
the lower frame rail and the upper frame rail at the point of
attachment of the forward hoop brace. If these braces do not
extend to the front hoop, an additional brace or gusset must
be installed at the point of attachment to the main rear hoop or
lower frame rail or other major frame member in such a manner
as to reinforce the attachment point to help prevent collapse
of the frame rail at the point of attachment. These tubes shall
be 1” x .080” minimum and gussets shall be 14 gauge - .078”
minimum thickness."
So which of the tubes in the attached photo need to be 1" x 0.080"? I don't want to prejudice the answer by saying what I think first, other than it clearly includes A, B, & C...
Thanks,
-Jim