The tires have us a hardness of the rubber that comes normally expressed in “Shore”.
This is an unit of certifyd measure and from the tests that I have executed, creed that the tires us “standard” would have to be of 50C.
I have realized of the tires us to high grip, with silicon rubber from 30c.
Now I must invent a system of front chassis with bearings in order to diminish the friction and to increase the weight front.
At the moment I do not have photo but soon I make to see the photos you of my tires us greens… 😀