Roll over bars provide occupant protection in the event of the car rolling onto its roof, a substantial safety upgrade on any classic MG roadster, where the absence of any structural roof means an unprotected occupant is vulnerable in a rollover situation. The roll over bar is a structural tube (or set of tubes) mounted behind the seats, sized to support the weight of the car in the event of an inversion and to maintain a survival space inside the cabin above the seat back rests.
Single-Hoop Roll Bars
Single-hoop roll bars are the simplest pattern, a single arched tube mounted behind the seats, with the lower ends bolted to structural mounting points on the bodywork. The hoop extends from approximately the centre console area up to roof level and back down to the rear shelf or bulkhead, forming an inverted U-shape above the seats. The bar is sized for sufficient strength to support the car's weight in the event of a rollover, with appropriate wall thickness in the tubing and structural mounting points capable of distributing the impact load to the body shell. Single-hoop bars are popular for classic-MG applications because they provide meaningful protection without the visual intrusion of a multi-tube cage, the single arch is relatively unobtrusive when viewed from outside the car with the hood down.
Multi-Tube and Cross-Braced Bars
Multi-tube roll bars add additional tubing to the basic hoop pattern, providing more substantial protection at the cost of slightly more visual intrusion. Common patterns include the cross-braced hoop (with a horizontal tube across the back of the hoop providing lateral rigidity) and the four-point bar (with additional vertical tubes from the hoop ends down to the floor at the rear of the cabin, distributing the rollover load more widely). Multi-tube bars are typically chosen for cars used in competition (where regulations require specific roll-bar specifications) or for cars used spiritedly on the road where the additional protection is valued by the owner. The choice between single-hoop and multi-tube depends on the owner's intended use and the balance between protection and visual character.
Finish Options and Installation
Roll over bars are stocked in several finish options. Chrome-plated bars present a polished bright appearance that suits cars with chrome bumpers and other brightwork. Stainless-steel bars provide similar appearance with better long-term durability, no risk of the chrome plating failing over years of service. Powder-coated bars (typically in black) provide a more subdued appearance suited to cars built to a sporting or competition character.
The installation involves bolting the bar to specific structural mounting points on the bodywork, typically reinforced areas of the rear bulkhead and the inner sills, with the appropriate large-diameter mounting bolts and structural reinforcement plates. The result is a permanent structural addition to the car that provides meaningful occupant protection without compromising the convertible character of the roadster. The technical team is available to advise on the right roll-bar specification and installation approach for a specific car and intended use.