There has been alot of talk about tubing used in building roll cages and chassis. Below is couple links to really good information about tubing and roll cage materials.
SCORE Rule Book Update:
Material
Roll Cage Tubing Sizes
Construction Procedures
Roll Cage and Vehicle annual inspection
BITD Rule Book.
ROLLCAGES:
Roll Cage Design 101
Building A Roll Cage For Your Ford Ranger/Bronco II
Dom_Process
SCORE Rule Book Update:
All vehicles in competition except Motorcycles and ATV’s must be equipped with a roll cage. Minimum design and tubing size based on seamless 4130 chromoly tubing or ASTM 1018/1026 CDS/DOM. No aluminum or other non-ferrous material permitted.
Material
Material for roll cage construction must be 4130 chromoly tubing or ASTM 1018/1026 CDS/DOM. All welding must be of the highest quality with full penetration and no undercutting of the parent metal. All welds shall conform to the American Welding Society D1.1, Structural Welding Code, Chapter 10, Tubular Structures and Standards for the material used (see AWS. Org). It is strongly recommended that the welder inspect all welds using Magnafluxâ„¢, die-penitent, or other effective methods.
All tubes must be welded 360-degrees around the circumference of the tube. No oxy-acetylene brazing or welding allowed. Good external appearance of a weld does not necessarily guarantee its quality, poor looking welds are never a sign of good workmanship.
None of the tubing may show any signs of crimping or wall failure. All bends must be mandrel type. The center radius of the bends may not be less than three (3) times the outside diameter of the roll cage tubing.
It must be emphasized that the use of heat-treated or high carbon steels may cause problems and that bad fabrication may result in a decrease in strength (caused by brittle heat-affected zones), inadequate ductility and internal stress.
All tubes must be welded 360-degrees around the circumference of the tube. No oxy-acetylene brazing or welding allowed. Good external appearance of a weld does not necessarily guarantee its quality, poor looking welds are never a sign of good workmanship.
None of the tubing may show any signs of crimping or wall failure. All bends must be mandrel type. The center radius of the bends may not be less than three (3) times the outside diameter of the roll cage tubing.
It must be emphasized that the use of heat-treated or high carbon steels may cause problems and that bad fabrication may result in a decrease in strength (caused by brittle heat-affected zones), inadequate ductility and internal stress.
Roll Cage Tubing Sizes
For the purposes of determining roll bar tubing sizes, vehicle weight is as raced, but without fuel and driver. Note: There is an allowance of minus 0.010 inches on all tubing thicknesses. Minimum tubing size for the roll cage is:
Up to 2000 lbs. 1.500†x 0.095†CDN/4130/Seamless or ASTM 1018/1026 CDS/DOM
2001 - 2500 lbs. 1.500†x 0.120†CDN/4130/Seamless or ASTM 1018/1026 CDS/DOM
2501 - 3000 lbs. 1.750†x 0.095†CDN/4130/Seamless or ASTM 1018/1026 CDS/DOM
3001 - 4000 lbs. 1.750†x .120†CDN/4130/Seamless or ASTM 1018/1026 CDS/DOM
Over 4000 lbs. 2.000†x 0.120†CDN/4130/Seamless or ASTM 1018/1026 CDS/DOM
Up to 2000 lbs. 1.500†x 0.095†CDN/4130/Seamless or ASTM 1018/1026 CDS/DOM
2001 - 2500 lbs. 1.500†x 0.120†CDN/4130/Seamless or ASTM 1018/1026 CDS/DOM
2501 - 3000 lbs. 1.750†x 0.095†CDN/4130/Seamless or ASTM 1018/1026 CDS/DOM
3001 - 4000 lbs. 1.750†x .120†CDN/4130/Seamless or ASTM 1018/1026 CDS/DOM
Over 4000 lbs. 2.000†x 0.120†CDN/4130/Seamless or ASTM 1018/1026 CDS/DOM
Construction Procedures
Cages must be securely mounted to the frame or body and gussetted and braced at all points of intersection. Cab or body mounted cages must not be attached to the body structure by direct welding, but must be bolted through and attached by the use of doubler plates (one on either side) with a minimum thickness of .187â€ÂÂ, see Figure 4. Where bolt and nuts are used the bolts shall be at least .375†diameter SAE Grade 8 or equivalent.
Roll cage terminal ends must be located to a frame or body structure that will support maximum impact and not shear. Minimum material dimension requirements for roll cages apply to the following members of the roll cage:
(1) Front and rear hoop
(2) Front and rear interconnecting bars
(3) Rear down braces
(4) Lateral bracing
(5) Elbow and door bars
(6) Lower A-pillar tubes, and lower B-pillar tubes Roll Cage Design
All roll cages must be constructed with at least one (1) front hoop (top of cage to floor), one (1) rear hoop(top of cage to floor), two (2) interconnecting top bars, two (2) rear down braces and one (1) diagonal brace and necessary gussets, see Figure 1. If front and/or rear hoop terminate at elbow/door bar, lower A-pillar and/or B-pillar must be made of same tubing size as roll cage. Centerlines of all required tubes must converge at intersections.
Any vehicle that is not provided with stock steel doors for its driver and co-driver must be equipped with sidebars, at least one on each side that will protect the occupants from the side. These bars must be parallel to the ground (or as close to parallel as is practical) and be located vertically in relation to the occupants to provide maximum protection without causing undue difficulty in entering or exiting the vehicle. The sidebars must be formed of tubing of the same material and dimensions as the roll cage itself and must be securely attached to the cage’s front and rear members. Additional side tubes may be required to limit cockpit intrusion, these additional tubes must be of the same size tubing as the roll cage. Tubes must be placed in such a manner as to limit openings adjacent to the occupants. Maximum opening size in this area is limited to 370 square inches.
All roll cage bars must be at least 3†in any direction from the driver and co-driver’s helmets while they are in their normal driving positions. Gussets must be installed at all main intersections on the main cage including diagonal and rear down braces, and where single weld fractures can affect driver’s safety. Gussets may be constructed of .125†X 3†X 3†flat plate, split, formed and welded corner tubing, or tubing gussets the same thickness as the main cage material, see Figure 2 and Figure 3. Rear down braces and diagonal braces must angle no less than 30 degrees from vertical.
An inspection hole of at least .187†diameter must be drilled in a non-critical area of the roll bar hoop to facilitate verification of wall thickness. It is the prerogative of SCORE to drill a second hole if deemed necessary.
Any cage or chassis that has been built after January 1, 2006 must be identified by means of an identification plate affixed to it by the manufacturer; this identification plate must be neither copied nor moved (i.e. embedded, engraved or self destroying sticker). The identification plate must bear the name of the manufacturer, a serial number, and the date of manufacturer.
Head/neck restraints designed to prevent whiplash are required on all vehicles. These restraints must be a headrest of approximately 36 square inches, with a resilient padding at least 2†thick. Any portion of the roll bar or bracing which might come in contact with the helmet must be padded.
Roll cage terminal ends must be located to a frame or body structure that will support maximum impact and not shear. Minimum material dimension requirements for roll cages apply to the following members of the roll cage:
(1) Front and rear hoop
(2) Front and rear interconnecting bars
(3) Rear down braces
(4) Lateral bracing
(5) Elbow and door bars
(6) Lower A-pillar tubes, and lower B-pillar tubes Roll Cage Design
All roll cages must be constructed with at least one (1) front hoop (top of cage to floor), one (1) rear hoop(top of cage to floor), two (2) interconnecting top bars, two (2) rear down braces and one (1) diagonal brace and necessary gussets, see Figure 1. If front and/or rear hoop terminate at elbow/door bar, lower A-pillar and/or B-pillar must be made of same tubing size as roll cage. Centerlines of all required tubes must converge at intersections.
Any vehicle that is not provided with stock steel doors for its driver and co-driver must be equipped with sidebars, at least one on each side that will protect the occupants from the side. These bars must be parallel to the ground (or as close to parallel as is practical) and be located vertically in relation to the occupants to provide maximum protection without causing undue difficulty in entering or exiting the vehicle. The sidebars must be formed of tubing of the same material and dimensions as the roll cage itself and must be securely attached to the cage’s front and rear members. Additional side tubes may be required to limit cockpit intrusion, these additional tubes must be of the same size tubing as the roll cage. Tubes must be placed in such a manner as to limit openings adjacent to the occupants. Maximum opening size in this area is limited to 370 square inches.
All roll cage bars must be at least 3†in any direction from the driver and co-driver’s helmets while they are in their normal driving positions. Gussets must be installed at all main intersections on the main cage including diagonal and rear down braces, and where single weld fractures can affect driver’s safety. Gussets may be constructed of .125†X 3†X 3†flat plate, split, formed and welded corner tubing, or tubing gussets the same thickness as the main cage material, see Figure 2 and Figure 3. Rear down braces and diagonal braces must angle no less than 30 degrees from vertical.
An inspection hole of at least .187†diameter must be drilled in a non-critical area of the roll bar hoop to facilitate verification of wall thickness. It is the prerogative of SCORE to drill a second hole if deemed necessary.
Any cage or chassis that has been built after January 1, 2006 must be identified by means of an identification plate affixed to it by the manufacturer; this identification plate must be neither copied nor moved (i.e. embedded, engraved or self destroying sticker). The identification plate must bear the name of the manufacturer, a serial number, and the date of manufacturer.
Head/neck restraints designed to prevent whiplash are required on all vehicles. These restraints must be a headrest of approximately 36 square inches, with a resilient padding at least 2†thick. Any portion of the roll bar or bracing which might come in contact with the helmet must be padded.
Roll Cage and Vehicle annual inspection
All vehicles must have their cages approved prior to racing in a SCORE event. The inspection will be preformed at the SCORE Technical office. After passing inspection and paying Inspection fees all vehicles will receive a SCORE I.D. tag, that is to remain with the vehicle at all times. If tag is removed or lost vehicle must be re-inspected and retagged. Any modification to an approved cage may render its approval invalid, and may need to be re-approved. All repairs to a roll cage damaged after an accident must be re-approved by SCORE International.
All vehicles built before January 1, 2006 may be required to have an inspection every six months
All vehicles built before January 1, 2006 may be required to have an inspection every six months
BITD Rule Book.
ROLLCAGES:
Table 2. Minimum Tubing Dimension
Note: See manufacturer’s’ reference charts for alloy steel tubing equivalent strengths. No aluminum or other nonferrous materials are permitted.
Material :
Vehicle Weight
Open Cockpit
Closed Cockpit
Under 2000 lbs.
1.5" x 0.90"
1.5" x .090"
2000 to 2999 lbs.
1.75" x .120"
1.5" x .120"
3000 to 3999 lbs.
2" x .120"
1.75" x .120"
4000 pounds and over
2.25" x .120"
2†x .120"
Roll cage construction material may be crew, dom, whr, wcr mild carbon steel or 4130 chromoly.
UTVRA HIGHLY RECOMMENDS THE USE OF 4130 CROMOLY or 1018/1012/ASTM/DOM. All welds must be of high quality and craftsmanship with good penetration and with no undercutting of parent material. Stress relieve all welded intersections by flame annealing.
Roll cage Design
All roll cages must be designed and constructed with one front vertical hoop, one rear vertical hoop, two interconnecting top bars, two rear down braces, one diagonal brace and all necessary gussets. The two top interconnecting bars must be placed as far to the outside of the top part of the front and rear hoops as possible. Rear down braces and diagonal brace must angle a minimum of 30 degrees from vertical. At the bottom of the diagonal brace there must be a cross member of the same tubing material and dimensions as the hoop. All roll cage components (hoops, braces, gussets, etc.) must have a minimum of 3-inch clearance from the component to the vehicle occupant’s helmets when occupants are seated in their normal riding positions. All portions of the roll bar or bracing that might come into contact with the vehicle occupant’s helmets must be padded.
Roll cages must be securely mounted to the frame or body. All intersecting points must be gusseted and braced. Cab or body mounted roll cages must be bolted through the body structure and be attached by use of a minimum two 0.1875-inch thick plates (one on each side of body structure). Bolts and nuts must be at least 0.375-inch-diameter s.a.e. Grade 8 or equivalent aircraft quality. Welding of cab or body mounted rollcages to body structure is strictly prohibited. Rollcage terminal ends must be attached to a frame or body member that will support maximum impact and not shear or allow more than 1.5 inches of movement in the cage terminal end.
All vehicles including those with stock steel doors must have at least one side bar on each side of vehicle that will protect occupants from side impact. The side bars must be of the same tubing material and dimensions as the rest of the rollcage. The side bars must be as close to parallel to the ground as possible, be located to provide maximum protection to the occupants, and be securely welded to the front and rear hoops. The location of the sidebars must not cause difficulty in entering or exiting the vehicle.
Gussets constructed of 0.125-inch x 3-inch x 3-inch flat-plate or split, formed and welded corner-tubing, or tubing-gussets made of the same material and thickness as the rollcage may be used. Gussets must be installed at all major intersections, including diagonal and rear down braces, where single weld fractures can affect occupants’ safety.
Restricted:
Oxy-acetylene brazing on rollcage is strictly forbidden.
Recommended: 4130 chromoly is highly recommended for all rollcage construction.
Note: See manufacturer’s’ reference charts for alloy steel tubing equivalent strengths. No aluminum or other nonferrous materials are permitted.
Material :
Vehicle Weight
Open Cockpit
Closed Cockpit
Under 2000 lbs.
1.5" x 0.90"
1.5" x .090"
2000 to 2999 lbs.
1.75" x .120"
1.5" x .120"
3000 to 3999 lbs.
2" x .120"
1.75" x .120"
4000 pounds and over
2.25" x .120"
2†x .120"
Roll cage construction material may be crew, dom, whr, wcr mild carbon steel or 4130 chromoly.
UTVRA HIGHLY RECOMMENDS THE USE OF 4130 CROMOLY or 1018/1012/ASTM/DOM. All welds must be of high quality and craftsmanship with good penetration and with no undercutting of parent material. Stress relieve all welded intersections by flame annealing.
Roll cage Design
All roll cages must be designed and constructed with one front vertical hoop, one rear vertical hoop, two interconnecting top bars, two rear down braces, one diagonal brace and all necessary gussets. The two top interconnecting bars must be placed as far to the outside of the top part of the front and rear hoops as possible. Rear down braces and diagonal brace must angle a minimum of 30 degrees from vertical. At the bottom of the diagonal brace there must be a cross member of the same tubing material and dimensions as the hoop. All roll cage components (hoops, braces, gussets, etc.) must have a minimum of 3-inch clearance from the component to the vehicle occupant’s helmets when occupants are seated in their normal riding positions. All portions of the roll bar or bracing that might come into contact with the vehicle occupant’s helmets must be padded.
Roll cages must be securely mounted to the frame or body. All intersecting points must be gusseted and braced. Cab or body mounted roll cages must be bolted through the body structure and be attached by use of a minimum two 0.1875-inch thick plates (one on each side of body structure). Bolts and nuts must be at least 0.375-inch-diameter s.a.e. Grade 8 or equivalent aircraft quality. Welding of cab or body mounted rollcages to body structure is strictly prohibited. Rollcage terminal ends must be attached to a frame or body member that will support maximum impact and not shear or allow more than 1.5 inches of movement in the cage terminal end.
All vehicles including those with stock steel doors must have at least one side bar on each side of vehicle that will protect occupants from side impact. The side bars must be of the same tubing material and dimensions as the rest of the rollcage. The side bars must be as close to parallel to the ground as possible, be located to provide maximum protection to the occupants, and be securely welded to the front and rear hoops. The location of the sidebars must not cause difficulty in entering or exiting the vehicle.
Gussets constructed of 0.125-inch x 3-inch x 3-inch flat-plate or split, formed and welded corner-tubing, or tubing-gussets made of the same material and thickness as the rollcage may be used. Gussets must be installed at all major intersections, including diagonal and rear down braces, where single weld fractures can affect occupants’ safety.
Restricted:
Oxy-acetylene brazing on rollcage is strictly forbidden.
Recommended: 4130 chromoly is highly recommended for all rollcage construction.
LOORRS Rules:
UTVR-15 ROLL CAGE & CHASSIS
A. All vehicles must utilize the stock chassis and maintain stock appearance. The stock chassis (frame) is defined as the main lower rails running along the inner sides of the UTV and the front and rear tubes that connect them. The chassis may be modified for durability and strength but must retain the stock width, length, and configuration. Any modifications must be pre-approved by LOORRS officials.
B. No bolts on connections to chassis are allowed. All joints must be welded and attached to the frame securely.
5
C. After market roll cage required.
D. Cages must be constructed with one front vertical hoop, one rear vertical hoop, two interconnecting top bars, two rear down braces, one diagonal brace, and all necessary gussets.
1. Two top interconnecting bars must be placed as far to the outside of the top part of the front and rear hoops as possible.
2. Rear down braces and diagonal brace must angle a minimum of 30 degrees from vertical. At the bottom of the diagonal brace there must be a cross member of the same tubing material and dimensions as the hoop.
E. There must be a minimum of 3 inches clearance between driver’s helmet and roll cage.
F. Gussets must be installed at all major intersections, including diagonal and rear down braces, where single weld fractures can affect occupant’s safety.
G. Gussets may be constructed of minimum .090 inch x 3 inch x 3 inch flat plate or tubing gussets made of same material and thickness as roll cage.
H. Roll cage terminal ends must be attached to a frame or body member that will support maximum impact and not shear or allow more than 1 ½ inches of movement in the cage terminal end.
I. Minimum tubing diameter and thickness is 1 ½ inch diameter by .095.
J. Roll cage material must be dom or 4130 chromoly.
K. All tubing, welds, gussets, and roll cage construction must be approved by LOORRS.
L. Top left half of roll cage above driver’s head must have 1 ½ inch x .095 inch ‘X’ diagonal
bracing bars and/or be covered with .125 inch minimum aluminum plate.
a. If plate is used, a single diagonal bar is sufficient.
b. Plate must be attached with 2 bolts on each of the four sides.
M. Entire roof must be covered with sheet metal or .063 inch minimum aluminum.
A. All vehicles must utilize the stock chassis and maintain stock appearance. The stock chassis (frame) is defined as the main lower rails running along the inner sides of the UTV and the front and rear tubes that connect them. The chassis may be modified for durability and strength but must retain the stock width, length, and configuration. Any modifications must be pre-approved by LOORRS officials.
B. No bolts on connections to chassis are allowed. All joints must be welded and attached to the frame securely.
5
C. After market roll cage required.
D. Cages must be constructed with one front vertical hoop, one rear vertical hoop, two interconnecting top bars, two rear down braces, one diagonal brace, and all necessary gussets.
1. Two top interconnecting bars must be placed as far to the outside of the top part of the front and rear hoops as possible.
2. Rear down braces and diagonal brace must angle a minimum of 30 degrees from vertical. At the bottom of the diagonal brace there must be a cross member of the same tubing material and dimensions as the hoop.
E. There must be a minimum of 3 inches clearance between driver’s helmet and roll cage.
F. Gussets must be installed at all major intersections, including diagonal and rear down braces, where single weld fractures can affect occupant’s safety.
G. Gussets may be constructed of minimum .090 inch x 3 inch x 3 inch flat plate or tubing gussets made of same material and thickness as roll cage.
H. Roll cage terminal ends must be attached to a frame or body member that will support maximum impact and not shear or allow more than 1 ½ inches of movement in the cage terminal end.
I. Minimum tubing diameter and thickness is 1 ½ inch diameter by .095.
J. Roll cage material must be dom or 4130 chromoly.
K. All tubing, welds, gussets, and roll cage construction must be approved by LOORRS.
L. Top left half of roll cage above driver’s head must have 1 ½ inch x .095 inch ‘X’ diagonal
bracing bars and/or be covered with .125 inch minimum aluminum plate.
a. If plate is used, a single diagonal bar is sufficient.
b. Plate must be attached with 2 bolts on each of the four sides.
M. Entire roof must be covered with sheet metal or .063 inch minimum aluminum.
Roll Cage Design 101
Building A Roll Cage For Your Ford Ranger/Bronco II
Dom_Process
