Trying to sort out seat/rollbar config for a Miata and trying to figure out the height requirement. That is how to pass the broomstick test.

From the 2015 SCCA Solo regs:
APPENDIX C - SOLO® ROLL BAR STANDARDS
A. BASIC DESIGN CONSIDERATIONS
1. The basic purpose of the roll bar is to protect the driver in case the
vehicle rolls over. This purpose should not be forgotten.
2. The top of the roll bar shall not be below the top of the driver’s helmet
when the driver is in normal driving position, and shall not be more
than 6 inches behind the driver. It is strongly suggested that the roll
bar extend at least 3 inches (3”, 76.2 mm) above the driver’s helmet. In
case of two-driver cars, both drivers must be within the roll bar height
requirement, however only one (1) driver must be within 6 inches (6”,
152.4 mm) of the roll bar. In a closed car or an open car with a remov-
able OE hardtop which is equipped with a roll bar/cage, it must be as
close as possible to the interior top of the car.
...

I thought the rule was the helmet had to be 2" below the top of the bar (there are references on the web to SCCA Solo I App K that state this.)

So did the rule change at some point? Are the Solo App C rules as above what are used locally for lapping/time attack?
If so sounds like as long as the helmet is below the roll bar I should be good (lower is better of course), right?

Those are the SCCA regs, you need to reference the ASN regs. This is how I found them:

Checked the lapping regs (http://www.asncanada.com/2013-SoloSport ... ations.pdf), found this section:



Then found this pdf: http://www.asncanada.com/2014-ASN-Solos ... 014_dh.pdf

Page 118:



So there is your 2" rule, although it depends on what your consider a "roof".

Of course, there are the time attack regs which have yet another set of rules and the material requirements are less stringent if you use DOM. But it does have the 2" rule.

http://www.asncanada.com/2014-ASN-Solos ... ations.pdf



Confused yet?

_________________
'99 BMW M3 / "Elvic"

No, not confused yet, but haven't read all of these ASN regs. Thanks for pointing me to the correct set of "local" rules, that would be a good start.

I started looking at the SCCA Solo stuff as the Hard Dog and Boss Frog roll bars state they are SCCA Solo compliant. The SCCA Solo tubing size per weight category is similar to the Time Attack Regs (though the HDHC and BF bars seem to meet ASN size for a Miata as well).

Yes, the definition of a roof does make it interesting when look at the line:
"The top of the roll bar shall be at least 5.08 cm (2") above the top of the competitor helmet or as close to the roof as possible."

I could see a soft top not being considered a roof, but what about an OE hardtop?

Out of curiosity checked the SM regs which use Section 9.1.7 (Spec Miata Class) and 9.3, 9.4 of the SCCA GCR and there is:
in 9.1.7 "When no top is used, driver shall wear arm restraints, and the cage will meet the helmet
clearance rule."
and in 9.4.B
"On all closed cars, the main hoop must be as close as possible to the roof and “B” pillars."
and
"On open cars retaining the windshield frame the main hoop
must be full height for the entire width of the hoop. The
top of the main hoop must be at least 2 inches above the
driver’s helmet..."

So again 2" or as close to the roof as possible depending on whether the car is open or closed. Are Spec Miatas with a hardtop considered closed or open cars? The line from 9.1.7 suggests they are considered closed with a hardtop.

Just curious BTW. The 2" rule sounds like a good idea for any car with a rollbar/cage so that's what I'll be aiming for.