Jupp, foam tires. It is the only choice for my outdoor hometrack. I discovered this conversation because I am still waiting for a RC10R5.1. I want to use this chassis for our F1 class and as the front needs to be low I tried some things and this just developed step by step in front of me.

Here is the still unfinished car:



It will become a Brabham BT-45b. Still have to think about the rear body posts (and have to look what I have lying around). I can't wait to drive this thing. Hopefully it will give the feedback of a real seventies F1-car