22.13. Dimension E must not be more than half height of the door aperture.
22.14. ASN Certified and non-Homologated ROPS constructed after 1.1.2001 in accordance with App. 13 Diagram 21 must also comply with the above dimensions.
22.15. Vehicles of Periods A-Z as defined within the current FIA yearbook for which a valid FIA Historic Technical Passport( HTP) has been issued – be fitted with a rollbar / rollcage as specified within the HTP issued for each individual Vehicle and with that Vehicle being in compliance with that specification.
23. Sports Racing Cars
Material
23.1. The rollbar must conform to App. 13 Diagram 64. a and 47. 23.2. Forward facing stays are permitted for open Sports Racing Cars. 23.3. Minimum height 92cm measured along the line of the driver’ s spine from the bottom of the car seat.
23.4. Cold drawn seamless carbon steel 350N / mm ².
Minimum Dimensions( mm) 23.5. 45 x 2.5( 1.75in x 0.095in) or 50 x 2.0mm( 2.00in x 0.083in).
24. Single Seat Racing Cars
Material
24.1. The rollbar must be symmetrical about the lengthwise centre- line of the car and of minimum height 900mm measured vertically from the base of the cockpit or 920mm measured along the line of the Driver’ s spine from the bottom of the car seat. There must be at least one brace rearwards from the top of the rollbar at an angle not exceeding 60 ° with the horizontal, this brace must be the same diameter as the rollbar, if two braces are fitted to the tube the diameter may be reduced to 26mm x 2.5mm( 1in x 0.095in). Where two braces are fitted, they may be rearward or forward facing.
24.2. The width inside the roll-over bar main tubes must be 380mm minimum measured 600mm above the base of the seat. It must incorporate a crossbrace to restrain the driver’ s head and give rearward support. The top hoop radius must not be less than 100mm measured at the centre line of the tube.
24.3. Cold drawn seamless Carbon steel 350N / mm 2
Minimum dimensions( mm) 24.4. Vehicles up to 470kg:
38 x 2.5( 1.5in x 0.095in) or 40 x 2.0( 1.6in x 0.083in). 24.5. Vehicles 470kg and over
45 x 2.5( 1.75in x 0.095in) or 50 x 2.0( 2.0in x 0.083in).
25. Other Considerations
25.1. An effective rollbar must be fitted with its top edge not less than 50mm above the helmet of the normally seated driver. It must be wider than the driver’ s shoulders at that height. It must be constructed of good quality seamless steel tubing of minimum 35mm diameter and wall thickness of 2mm. It should have the top bar straight or slightly curved but no tubes meeting in an inverted‘ V’. It must be effectively braced to structural members.
25.2. Non-standard Vehicles are advised to fit a rollbar to the following minimum requirements.
a. Minimum height 72cm from the rear of the uncompressed seat cushion.
Motorsport UK National Competition Rules 2026 Edition 1
Chapter 7 Appendix 3- Roll Over Protection Systems( ROPS) 265