S-021S Sponge Tires for GpC Cars use S-014S rims.

S-021S BRM sponge tires to mount on S-014S rims. 27.8mm x 20.5mm rim x 16.5mm wide

Black sponge tires to fit to S-014S or replace sponge on S-021SS tire/rim set, need to be trued after gluing and fitting to the rim.