From the rules:
Inside roll bar requirements for standard cab pickups only:
A. Minimum of a 4 pt. bar, along with a diagonal cross brace and full-width
shoulder harness bar. Bar size will need to meet bar size ratio to weight of
pickup. Mounting will need to be as required in our roll bar specs. See
page 20.
Roll Bar Specifications
1. Participant acknowledges and agrees that they are solely responsible for the
safety of their own vehicle, and that it is the participant’s responsibility to ensure
compliance with the rules and regulations. Organizer shall have the right to
inspect any vehicle at any time to verify it is compliant with the rules and
regulations to the extent of organizer’s knowledge.
2. Roll Bar: A 4 pt. roll bar is mandatory in the Grand Touring and Grand Sport
Divisions, with a harness bar and a diagonal brace.
3. Basic Design Considerations: The basic purpose of the roll bar/roll cage is to
protect the driver in case the vehicle rolls over. This purpose should not be
forgotten.
21
A. The top of the roll bar shall not be below the top of the driver’s helmet in a
closed car and a minimum of two (2) inches above the driver’s helmet in
an open car when the driver is in the normal driving position. It shall not be
more than six (6) inches behind the driver.
B. Cars with factory built or factory reinforced roll structures may be allowed
in the 100, 105, 110, 115, and 120 class. They will be evaluated on a per
car basis. The decision of the race director will be final.
C. The two vertical members forming the side of the hoop shall not be less
than fifteen (15) inches apart, inside dimensions, at their attachment point
to the uppermost chassis member.
D. An inspection hole of at least 3/16-inch diameter must be drilled in a noncritical
area of the roll bar member to facilitate verification of wall
thickness. This should be at least three inches from any weld or bend.
4. Material: The roll bar hoop and all braces must be of seamless, DOM (Drawn
Over Mandrel), or a chrome moly or Docal steel tubing.
A. The size of the tubing to be used must be determined on the basis of the
weight and speed potential of the car.
5. Fabrication: The main vertical hoop must be one continuous length of tubing with
smooth continuous bends and no evidence of crimping or wall failure.
A. All welding must be of the highest quality with full penetration. All
attachment points must be welded 360 degrees around the tube.
B. Gussets should be welded at the junction of any tubes.
6. Bracing: It is recommended that braces be of the same size tubing as used for
the roll bar itself.
A. All roll bars must be braced in a for or aft direction with the brace attached
within six (6) inches of the top of the hoop, and at an angle of at least thirty
(30) degrees from vertical.
B. It is required that a diagonal brace be used to triangulate the main hoop,
and it is highly recommended that this brace be attached at the top on the
driver’s side and attached to the bottom on the “passenger” side.
C. A headrest is required if not part of the seat.
7. Mounting Plates: Roll bars and braces must be attached to the frame of the car
whenever possible. Mounting plates must be used for this purpose. When the
main hoop is attached to sheet metal, such as a floor attaching point for unibody
cars, the mount plate must be at least 36 square inches (6” x 6” plate) on both
sides of the sheet metal.
22
A. A minimum of double-nutted grade 5 bolts for self-locking or welded nuts
shall be used to bolt to the car. No bolts are needed if the bar is welded to
the car’s frame.
B. In the case of cars with unitized or frameless construction, mounting
plates must be used to secure the roll bar structure to the floor of the car.
The important consideration is that the load be distributed over as large an
area as possible. A back-up plate of equal size and thickness must be
used on the opposite side of the panel with the plates through-bolted
together.
8. Removable Roll Bars: Removable roll bars and their braces must be very
carefully designed and constructed to be at least as strong as a permanent
installation. If one tube fits inside another to facilitate removal, the removable
portion must bottom on the permanent mounting, and the mounting hardware
used to secure each joint must be grade five (5) or better. It is recommended that
the telescope section be at least eight (8) inches in length.
9. Installations On Cars Of Space Frame Or Frameless Design: It is important that
the structures be attached to cars in such a way as to spread the loads over a
wide area. It is not sufficient to simply attach the roll bar to a single tube or
junction of tubes. The roll bar must be designed in such a way as to be an
extension of the frame. Considerable care must be used to add as necessary to
the frame structure itself in such a way as to properly distribute the loads. It is not
true that a roll bar can only be as strong as a single tube of the frame. On cars of
frameless construction, consideration should be given to using a vertical roll bar
hoop of 360 degrees completely around the inside of the car, and attaches with
suitable mounting plates. This type of roll bar then becomes a substitute for the
frame.
10. Other Designs: Deviations from the above will be considered.
11. Roll Bar Padding: Roll bar padding should be used to protect the driver/navigator
in all areas of possible contact.
12. Minimum Tubing Sizing: The size of the tubing to be used shall be determined on
the basis of the weight and speed potential of the car.
2700 lbs. & over
DOM 1.75” O.D. x .120 wall
Alloy (CM) 1.75 x .120 wall
