Are there recommendations for flexible black filament for printing toy-tires?
I don’t need it for rc-cars, more like bigger “matchbox”-Cars. The tires should grip well and roll instead of slide when the car is shoved by the kid.
The easiest is hubs with low durometer orings for tires. Otherwise if you are in for some tuning, try this: https://flexionextruder.com/shop/x60-ultra-flexible-filament-black/
It makes NinjaFlex look like a steel rod 
Thx for the detailed instructions!