Tires: Tires: w/ or w/out air, solid rubber tires, solid tires

Question
Why don't they just make tires solid rubber so they don't go flat and are always balanced?

Answer
Stephanie.

Because hollow tires inflated with air have a much softer ride than solid tires.

They invented pnuematic tires in the early years of autmobiles and by the 1930's pretty much the only vehicles using solid rubber tires were off the road trucks, and today, even those tires are gone.

Besides solid rubber doesn't mean the tire will always be balanced.  Wheels by themselves have some imbalance.

Hope this helps.