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The rules set down hereafter are for each wheel assembly that comprises a manufactured outer rim of pressed and/or rolled steel welded to a centre section of flat or pressed steel plate or web which is centrally mounted to the hub with conventional stub and axles. The centre hole of the wheel must fit the axle hub. Refer to SNZ website: for latest information on approved components. (a) All steel wheels must be inspected at CVI and date-stamped. (b) The life expectancy of OEM steel road wheels is three years. OEM steel road wheels must not be used after three years use. (c) OEM Cortina front stub axles are not permitted on Super Saloons. Re-manufactured Cortina stub axles are permitted T11-7-1 Lightening: (Refer to Diagrams on following pages) T11-7-2 Subject to the following provisions, all or any lightening holes must be symmetrical with respect to the studs. T11-7-3 In any one wheel, lightening holes should be identical in shape or, in the case of a number of smaller holes and various diameters, in pattern. T11-7-4 The distance from any stud hole to any adjacent hole as in Diagram 'A' must not be less than 40 mm. Excepting Super Saloon (front & rear) (wheels must not be less than 38mm. Except as stated in T11-9-2(e). T11-7-5 The maximum amount of metal removed from a „spokedâ€&#x; web for lightening purposes when measured: (a) On any circle circumscribed on the centre, from the minimum inside radius of the rim, should not exceed one half of any such circumference. Nor shall more than 50 percent of area the area of the web be moved. (b) Radially, shall be outside of the P.C.D (Peripheral Circle Diameter) of the studs, excepting as is stated in T11-7-7 (a) and (b) below. T11-7-6 Where a web comprises a full disc on its outer circumference (a) The minimum radius within the lightening holes shall be one sixth of the minimum distance between any two studs, PROVIDED the 50% welding rule as below in Rule T11-7-7-(a) is maintained. (b) The minimum distance from an inside surface of any lightening hole to the nearest adjacent outer surface on a web before welding may be 25mm. (c) The web thickness to be 8mm minimum. T11-7-7 Welds: connecting the web to the inside of the rim (a) Shall have a total length of not less than 50% of the circumference around the welding circle, or equivalent peripheral length. (b) Shall be uniform and evenly spaced around the periphery, and have a fillet size of not greater than 50% of the web material thickness. (c) And where a web is in a 'spoked' configuration, both sides of each spoke shall be welded to the rim, over their full peripheral length, excepting only as in (d) below (d) And where the spokes or web itself fills in more than 75% of the circumference of the rim, alternate 'stepped' welding may be used, but each weld shall have a length of not more than 1/8 of the diameter, measured around the circumference, the total of all welds at the rim to occupy the full outer circumference of the web where it joins the rim. (e) To be from welding rods which are compatible with the rim and web material.



2010 NZ Speedway Rule Book  
2010 NZ Speedway Rule Book  

2010 NZ Speedway Rule Book