winabbey wrote:
BLMC Service Liaison Summaries relating to Police specification tyres are as follows:
SLS 132 (1st Nov 1967) - Olympic GT radial ply tyres
SLS 212 (6th Oct 1970) - Dunlop Sports Radial Aquajet
SLS 4/71 (1st Nov 1971) - Clubman GT - Goodyear Sports Radials. "It has been reported that handling problems have occurred with Dunlop Aquajets which were previously used on Police Cooper S vehicles."
Following is an extract from Dunlop UK website:
"In the early sixties, the Dunlop Technical team faced the huge challenge of making tyres grip at high speeds on wet roads. At the same time, laboratories and research stations the world over realised worn tyres suffered 'aquaplaning' - a phenomenon where a tyre floats on water and loses all braking grip.
With its circumferential grooves and rigid structure, Dunlop's SP 41 radial ply tyre, gave drivers complete protection from aquaplaning, assuming moderate speeds and reasonable pattern depth. In 1964, Dunlop technician, Tom French patented a breakthrough advance in tyre tread design. The tyre included a system of 'microslots' that soaked up surface water like a sponge and expelled it later."
Presumably that last tyre is the Aquajet.
Following is from the Longstone Classic Tyre website showing Aquajets as standard in 1965:
"The first E-Type Jaguar was fitted with a 640H15 Dunlop RS5 cross ply tyre until 1965 when the factory offered the E Type with a Dunlop SP Sport Aquajet 185HR15 radial tyre as an alternative. This ,now classic, tyre became standard fitment to all series one Jaguar XKE's and series two Jaguar E-Types."
It would be interesting to know when they were first produced in 10" size in Australia.
The SP41 is not a aquajet, if memory serves was first fitted as standard to the new Jaguar XJ6 in about 69-70 and became available in 10 inch size late 70 early71, tries them in 73 and they were shocking tyres, don't blame the cops for not wanting them, thry had less grip in the wet than 3/4 worn bridgeston RD102s and therer dry performance was not even as good as the old SP41s
Jon
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Roundies and Clubbies(except vans) are both ugly that is why I have Midas and a van
1293 Mini Midas Bronze,1275 Clubman van
