Tamiya USA has announced a new F1 tire that fits the foam tire rim for the F104 series cars.
"New Tamiya F1 tires for the F-104 chassis!
We are proud to announce the introduction of two new rubber tire
compounds for the vastly popular Tamiya F104 Formula One chassis car
kits. The front tire is a soft compound designed to offer excellent
steering performance and the rear tire is a hard compound, which offers
high traction with excellent longevity and durability. The new tire
compounds fit the following Tamiya wheel sets: items 51378 and 54400.....
...The new item numbers for the tires are: 1031 RC F1 Tire Front (Soft) and 1032 RC F1 Tire Rear (Hard) The new tires will be available through hobby shops in early August."