Criticism Of Tyre Tread Depth

Press, Volume CVIII, Issue 31781, 11 September 1968, Page 11

Criticism Of Tyre Tread Depth

(N.Z. Press Association) WELLINGTON, Sept. 9. The proposed minimum tread depth on car tyres was inadequate, Professor G. A. Pedy, associate-profes-sor of physics at Victoria University, said today. The Minister of Transport (Mr Gordon) said last week that warrant of fitness legislation would be altered to require tyres to have a mini- | mum tread depth of .03 mm. Professor Peddy said that, with normal driving, tyres which had just passed the

minimum requirement would be bald well before the next warrant was due. “Unfortunately, people tend to believe that their vehicles are safe if they have a current warrant of fitness," he said.

Motorist’* Responsibility A Transport Department spokesman confirmed that ,03mm represented about 3 per cent or 300 miles in the life of a tyre estimated to last for 10,000 miles so that, theoretically, a tyre passed as sound one day could be bald at. the end of a long journey the next day. The chief automotive engineer at the Transport Department, Mr A. W. Keyes, agreed that this could happen, but the responsibility would be on the motorist to ensure his vehicle was in good order.

While the technicalities of the new regulation had not yet been worked out, he

imagined that measurements would be taken across the most worn section of the tyre; and if three-quarters of the tread was .03mm in depth or more, the tyre would be passed.