Yes I have. They have a very high TWI (Tread wear index). They are lethal in the wet. They're designed for RWs that love to claim massive mileages at the expense of grip. Think of your local trailer park. Correct, I fitted the Pirelli CN72 to mine, in the original fitment size. It has a very low TWI. It was the result of working with the Avon and Pirelli to maximise the suspension development I have done to my car. Simon and Lowball wax lyrically about price regarding certain aspects of classic car ownership. In my experience dealing with cars (and most things in life), I've found there are very few financial shortcuts to maximising one's enjoyment of a classic car. Putting your car on a club permit, or washing the car yourself are probably two. As for the mechanical aspect, I know of none. That is just my experience.
You clearly have NFI how to drive one of these cars ,I As I said I drive that old car in all conditions including Tassie and never an issue .....perhaps the way my car is set up (so well) it compensates for the tire -perhaps. I had fresh Avons on the Corniche and yes they are better tyre , I still ask why would you put the Pirelli on the S/S...Oh wait you know better than Rolls-Royce ?
The reason I put the CN72 on the Silver Shadow is because it's stiffer in the sidewall than the Avon. It worked better than the Avon with the revalved dampers, increased roll stiffness and higher tyre pressures I run in my car. One of the issues in tuning older car suspension with the classic series of tyres is that there are no modern equivalent tyre construction wise. A good example is the Michelin XWX. Two less bands of nylon and 4mm thinner sidewalls on the current offering. Usually, you can compensate by simply running 2-3 pounds more pressure to stiffen the sidewall a little. That works on the 911 and 308 no problem. On the Rolls Royce, it didn't.
Higher tyre pressures for FFS, when I 1st bought the Corniche,I drove it home from UK Motors and thought what have I bought, straight off put my tyre gauge on the tires,far to high ,bleed back to factory specs as per the book, issue solved. I might add after I fitted the new Konis ,I also put the pressures up ,same far too light in the steering ,Rolls-Royce provide a handbook use it . How is your ball joint wear ?
I adjusted all the ball joints in the front suspension when I recommissioned the car some 9,700 miles ago. I have just checked them again and there is no play. As an aside, it's a lovely feature that you can adjust the play in all the ball joints by adding shims to the base of the ball.
So nearly 50 year old springs .....err they would be ....'ed get some steel from Chinah and make up spacers ?
