This week's excitement was Car SOS (now nicknamed car Sausage) had a Sunbeam Alpine series 1 in for restoration. Early Alpines left the factory with 560X13 crossply tyres which are not currently produced as a sports car tyre. We only ever sell the 560X13 Camac, but it's not a sports car tyre.
Because the road's we drive on these days are very different to what they were in the '60s, we drive on so many more dual carriage ways these days, people predominantly choose to drive on a radial tyre. The radial equivalent to a 560X13 is either 155R13 or 165R13. I would suggest that the best tyres in these sizes currently are from the Michelin XAS range. These fantastic early asymmetric tyres dramatically improve the directional stability of a classic car. I have had them on several cars. My Daimler V8, Ford Cortina and now my Silver Shadow.
So many classic cars these days just get stuck onto wider rims. It is a miss conceived idea that wider wheels & tyres will just make your classic car better. Often really the reason is the availability of cheap modern tyres. Fitting modern oversized tyres spoils the handling of a classic car. The steering gets heavier, more vague and it doesn't turn in so precisely and quickly, added to that if you don't alter the camber of the car then you will have much less progressive handling, as the rear end brakes away more violently.
In the 60's they had nice light small tyres, in the 70's they had fat heavier tyres. In the '60s they had the mini skirt, In the 70's they had flairs. I know which I prefer.
I digress:- Because the tyre size 185/70R13 is as common as the hairs on a bares bum, there have been a good selection of cheap tyres available in this size. When I go to a classic car show I often have a browse of the Sunbeam Alpine stand because I kind of fancy one (pre series 4, with fins). I would suggest that the majority of Alpines I see are fitted with 185/70R13 tyres, and I often find myself bickering with them encouraging them to fit something smaller and more suited to the car than just buying on price. People tend to hate it when I tell them, they chose their tyre on price rather than suitability. I'm surprised I don't get punched more often.
When you are over tyreing a classic car, you can diminish the derogatory effect by fitting something with a period carcass, that was designed to complement a car that was originally designed for a thinner tyre, and to suit a car that doesn't have adverse camber. A period tyre will go some way to maintaining an old cars progressive handling, but keep the advantages of the wider tyre, which are diminishing wheel spin and stopping you locking up under braking, not symptoms I feel are associated with a Sunbeam Alpine. Without doubt, if I ever do get an Alpine my car will be on 155 possibly 165R13 tyres.
However:- The Car SOS car had got wider Minnilite wheels, and the good news for the Car Sausage team is that while they were restoring the Sunbeam Alpine, a new delivery of PIRELLI's fantastic 185/70VR13 CINTURATO ™ CN36 was being delivered to their depot, and I was able to pop into PIRELLI's shed, pick up 5 tyres and deliver and fit the tyres for them on Tuesday of this week. So although it has got oversized wheels on it we can maintain some of its progressiveness of handling by having the lovely rounded shoulders of the PIRELLI CINTURATO ™. There is an interesting article by a German magazine about the CINTURATO ™ CN36 tyres on this page http://www.longstonetyres.co.uk/page/classic-porsche-tyres
Published on 01/02/2017