Center of mass, three wheeled vehicle

I have a 3 wheeled vehicle with the front wheels one size and the back wheel about 30% that size. I played with the center of mass and mass itself a lot jut to be able to stop it from bouncing. As soon as I make the suspension distance 1 (now it's 0.1 due to its design) it stops bouncing. The question is, should I scale up the model so I can have a bigger suspension distance and stop it from bouncing? I also tried all possible combinations with bounciness of the phys material and project physics settings.