WHEELS AND TYRES

All wheels and tyres fitted must comply with the Road Traffic (Miscellaneous) Regulations 1999.

The main points to note are:-

(a) The wheel track must not be increased by more than 26mm beyond the maximum specified by the vehicle manufacturer. Maximum allowable tracks for individual vehicle models can be obtained from Transport SA. The wheel track is the distance measured across the vehicle from the centre-line of one tyre to the centre-line of the other tyre on the same axle.

(b) The wheels and tyres must not foul the body, suspension or any part of the vehicle under any operating conditions and must not project beyond the bodywork, when the wheels are in the straight ahead position and viewed from above.

(c) It is recommended that the tyres fitted to an axle of a vehicle must be of the same carcass construction. The tyre size designation of tyres fitted to an axle is required to be the same.

(d) The tyres fitted must be suitable for the rim. The tyre retailer should have information about matching tyres and rims.


(e) The load rating of the tyres must be adequate for the vehicle. ADR 24 vehicles (manufactured on or after 1/1/73) have this information listed on the tyre placard. The load rating of any tyre fitted must not be less than lowest load rating listed on the placard. For vehicles manufactured before 1/1/73 the tyresmust have a load carrying capacity equal to or greater than those supplied as standard equipment by the vehicle manufacturer.

(f) Spacers are not permitted between the hub and wheel (unless originally fitted by the manufacturer)

(g) If the wheels of a vehicle are retained by multiple nuts or set screws, not by splines and a single nut, then the wheel nuts must match the tapered holes in the wheel and the nuts must be engaged for their full depth of thread.

(h) Wheels that have been widened by inserting a spacer band are not permitted.

(i) Vehicles manufactured on or after 1 January 1973 (ADR 24) are not permitted to increase or decrease the diameter of the wheel by more than 50 mm than the largest or smallest wheel listed on the tyre placard.

(j) The overall diameter of a wheel and tyre fitted to a vehicle manufactured on or after 1 January 1973 (ADR 24) must not be more than 15 mm greater than the largest tyre size listed on the tyre placard and not more than 15 mm less than the smallest tyre size listed on the placard. Specifications for overall tyre diameters are listed in the Tyre and Rim Standards Manual, issued by the Tyre and Rim Association of Australia.

(k) Vehicles manufactured prior to 1 January 1973 are not required to comply with (i) and (j) above however consideration must be given to clearance of the tyres and wheels on suspension and body components.

(l) Passenger cars manufactured on or after 1/7/88 must also comply with ADR 18/.. that stipulates that the speedometer must indicate the actual vehicle speed, for all speeds above 40 kilometres per hour to an accuracy of plus or minus 10 percent.

When selecting aftermarket wheel rims for a motor vehicle, ensure that the offset of the rim does not vary by more than 13mm from the original rim fitted by the vehicle manufacturer. This will ensure that the wheel track is not increased by more than 26mm beyond the maximum specified by the vehicle manufacturer.

Transport SA has a list of maximum allowable wheel tracks for a large variety of vehicles and can be consulted to confirm if a wheel track is within acceptable limits.

Wheel rims fitted to passenger cars manufactured after 1st July 1985, which are not original equipment or an original equipment replacement by the vehicle manufacturer must be indelibly marked with the wheels nominal diameter, width and offset and with identification of the manufacturer of the wheel and the standard to which the wheel was manufactured. This should be checked before the wheels are purchased.

Tyres fitted to a vehicle must have a tread pattern at least 1.5 millimetres deep on all parts of the tyre that normally come into contact with the road surface. Tyres are manufactured with tread wear indicators that are located in the tyre grooves in at least four points around the circumference of the tyre. If the tread wear indicators are at the same level as the overall tread, or there is less than 1.5 millimetres of tread depth on the
tyre, then the tyre is considered to be illegal.

Tyres fitted to passenger cars may not be treated by recutting or re-grooving of the tread unless the tyre is constructed to do so and marked as such.

Cooper 7.5 inch disc and large (1 inch) stepped drum, 10x4.5 rim (on most 1275's)
Front - 125cm
Rear - 121cm

Might be a good time to go out and measure the track on my race car Im sure they'd be in the 130's all round

The track width varies between models / brake assemblies.


Narrow (1/2 inch) stepped drums, 10x3.5 rims (common on 1100's)
Front - 123cm
Rear - 119cm