Jaques in Pomerode-SC Brazil, sent me photos of his cool gravity racers... that he made for good roads, and off road, when he was a kid. Very cool! "carrinho de rolimã" in Portuguese

The rules on making competitive Rolima:
It must be no more than 1.5 m in length, with roller wheels and no steering wheel or sharp objects.

Simple huh!

But these wheels do not work on grass or dirt hills.

So Jaques used either wood wheels or lawn mower wheels to ride through grass and mud, and you see in the below image

His first car in 1994 was made by his father, based on a car that his father built for him. So, 3 generations have been enjoying a sport, that isn't difficult to get into, nor expensive to stay in.  His home town didn't have smooth paved roads when he was a kid, so they couldn't use some slick bearings for wheels, they had to go with these lamnmower wheels you see below.

https://www.bcnoticias.com.br/inscricoes-abertas-para-torneios-de-carrinho-de-rolima-e-de-pipas-em-camboriu/  top image only, the others are all from Jaques!

Thanks Jaques!