Wobble in brand new tires

2004 CHEVY VENTURE VAN W/77,000 MI. BRAND NEW TIRES WOBBLE AT 20-25 MPH. RETURNED TO TIRE CENTER TWICE WITHIN 2 WEEKS OF PURCHASE. BOTH TIMES TIRES WERE BALANCED AND I WAS SENT ON MY WAY. THE WOBBLE IS STILL THERE! WHAT NOW?

Check the tires for belt separation. Take each off the car and then roll them on a straight, smooth surface. If they wobble and fall over (before stopping), then the tire is bad, and it will be clear to the tire center.

Are you defining an imbalance as a wobble? To me they’re not the same thing.

What are the symptoms? Shaking at any particular speed, wallowing or wandering on the roadway, etc.?

If the wheels/tires are legitimately wobbling then maybe the problem is a loose suspension component or wheel bearing.

At 20 to 25 mph, this is probably a bent rim.

Tires would be felt at 50 to 70 mph.