Just got my wheels back from the powder coat guy. look great! problem is I never checked and it turns out they are 14inch not 15s. I can use them on another car,,,and I do have access to some 15s which of course would also need powdercoating. Should I stay pure and go for the 15s? Any advantage to the 14s? Previous owner must have thought so.
Thanks for any and all advice
There is often the perception that fatter tyres are better, which is not strictly true. They are different which is not always the same as better. fitting 165R14 over 155R15 will give you a more comfortable ride, having a slightly taller side wall, and it will give you more ultimate grip, less wheel spin and less locking up the wheels under braking, but they are not necessarily better. and they won't nesecarily corner better. And a much wider more modern tyre will definitely not corner as well.
there is plenty of choice for Duetto tyres listed on here Alfa Romeo Spider 1600 Duetto | Longstone Tyres
I would suggest that the difference between a 155R15 and a 165R14 is subtle. moving to something like a 185/70R14 will give a more marked difference, the handling will be less progressive and the steering heavier, these derogatory effects will be diminished by fitting a genuine period tyre, which is why it is so good that Pirelli now make the CN36 again. Fitting things like a 65% profile modern tyre will start to make a more marked difference. the carcass shape of more modern and lower profile tyres (like a 65% profile tyre) is less suited to the set up of cars like the Duetto from this period, and do not handle so well. they are designed to be fitted to cars with adverse camber and caster, which are not part of the set up of a Duetto.
Out of interest, i raced my Lotus Elite for the first time this weekend at Snetterton where i was against a wide range of other cars fitting fatter racing rubber, but in the wet i was pitted against another Elite with a much more powerful engine and for the first few laps i just drove round the outside of him on the long sweeping corner called Coram. I was fitting the standard equip 155HR15 Cinturato CA67 tyres that your car left the factory with.
Fitting fat tyres is not just a simple answer to more grip. It is worth pointing out that Alfa could have fitted fatter tyres to these cars if they thought they handled better. and yes they did move onto fitting 165HR14 Cinturato CA67 and later 165HR14 Michelin XAS. I think the very last Spiders had 185/70R14 as an option, but i also believe that the general perception is that these later cars weren't as nice to drive.