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T11-16-6 Bumpers (a) Front (optional), construction from maximum 20mm nominal bore medium steam pipe, must fit between, and be level or behind with, the leading edge of front tyres, mounted 2 points only. (b) Rear bumpers are compulsory. Construction shall be two rail loop as per sketch with rails not more than 250mm apart at 400mm average centre height, of 20mm 10 gauge nominal bore pipe, or single rail of 25mm nominal bore steam pipe, with minimum 100mm radius on each end returning, and attached to chassis. single rail centre height to between 400mm & 500mm. Bumper must also be long enough to protect at least half the width of both rear tyres. Note: Two rail hoops do not have to be vertical.

T11-16-7 Roll Cage (a) A minimum of 780mm wide at shoulder position on inside edges and be contained within body. (b) (i) Main body roll cage constructed from steel, a minimum of 32mm nominal bore medium steam pipe 3.25mm wall, or 38mm OD x 3mm W/T boiler tube or chromoly 1½� x 120 thou (this allows for manufacturing tolerances), and to follow interior contour of car. (ii) Roll cage to be welded to chassis, 6mm inspection holes can be drilled in main roll cage pipes if requested. (v) Must have a minimum of two sideways stays in car, suitably locked together. (vi) Parallel braces must be fitted from top rear of roll cage, to chassis, in front of, or behind rear axle. (c) Bracing Option 2 is the preferred bracing technique for all cars constructed after 1 Sept 2009 as defined in E1-1-3(b):(i) Option 1: Diagonal braces from bottom left of roll cage to top right of roll cage on opposite side. All cars to have X brace fitted in roll hoop. (ii) Option 2: An "A" frame brace consisting of 2 vertical braces attached to base of rear roll cage hoop and rising to be attached to centre of rear roll cage hoop. A measurement of 90mm must exist at the upper points of attachment to rear hoop. (iii) A minimum of two horizontal braces must be attached inside the said braces. The upper horizontal brace to be at driver shoulder height, the lower horizontal brace to be at approx. 500mm above drivers seat base. Centre line of "A" frame brace to be in centre line of driver's seat. Brace material: 25mm OD x 10 gauge minimum size. (d) A horizontal cross member, travelling across bulkhead, and attached to the roll cage on both sides approximately 500mm from the floor. (e) A horizontal cross member, travelling across behind the seat, and attached to the roll cage on both sides approximately 500mm from the floor. (f) Two (2) horizontal pipes 300mm apart minimum, 450mm apart maximum, on each side of the cab. The rectangle formed by the top and bottom cab rails and engine plate bar upright and main



2010 NZ Speedway Rule Book  

2010 NZ Speedway Rule Book