RB have released a range of foam tyres under their SpeedLine name and come mounted on fluorescent yellow rims. The rubber is manufactured in Japan whilst all other work is carried out in Italy. The packaging is designed to ensure the best storage. The front and rear 1:8 rims are lightweight, have 12 thin spokes and the special injection process makes the rim very well balanced and very round. The 1:10 and 1:12 versions are manufactured to the same standard with eight and six spokes respectively.
Other features of the Speedline foams and wheels is that every rim is individually ground for a better gluing process. They are also reamed and calibrated one by one to ensure a perfect wheel axle/wheel fitting but with the right tolerance. The Japanese foam is selected and the hardness checked. The foam is glued on the rim and machined to the right diameter. There is a second hardness check on three different points of the foam before the wheels are packaged into the special white and chrome air proof packaging.

Source: RB Products