Looks like Nova is making good 15 inch choices again

[Tbone1209]

The Historic line of race tires in 15inch looks to open up some alternatives for 15 inch Grp4 rears at least. I don't what would be applicable for the fronts. The All weather in 11/25-15 looks like a great choice. The caveat is the durometer is super soft but so are the TB15/5s. The Pirelli Corsa Classic W7 are 24.4 inches tall and these would be 25 inch according to the specs.

https://novamotorsport.com/products/avon-historic-cut-all-weather/

[Strat Fan]

The 8.5/23.5-15 for the front looks to be the best option.
It's maybe a shame there isn't a 10/25-15 as well as the 11/25-15 just to drop the section width down a little although the tread width isn't terrible on the 11

More modern but there is also the CT01 in 235/45/15 F & 285/40/15 which would work on a GP4

[Tbone1209]

The 8.5/23.5-15 for the front looks to be the best option.
It's maybe a shame there isn't a 10/25-15 as well as the 11/25-15 just to drop the section width down a little although the tread width isn't terrible on the 11

More modern but there is also the CT01 in 235/45/15 F & 285/40/15 which would work on a GP4

I'll ck those out!

[ChrisCar6]

Anybody know what's the maximum tyre diameter that'll fit Stradale arches? My tyres are 585mm and too small. IIRC the Alfa 164 gearbox was mated to 620mm diameter tyres. Tha Avon CR6ZZ 215/60-15 is 635mm diameter.