Xray XT8? Have you seen this? It's a good read whether you have an Xray vehicle or not:
http://www.teamxray.com/teamxray/sho...p?file_id=4461
Excessive ballooning can be caused by too thin of a diff oil in the center which will transfer too much power to the front wheels. This can be exacerbated by the rear suspension being too soft; the weight shifts rearward, give the rear tires more traction, so the diff send the power to the tires with least resistance; the fronts. This is much like getting a full scale car stuck and you see the stuck tire doing nothing while the other tire spins like crazy.
Another problem would be that your foams are shot. The foams could be disintegrating and they get flung off the rim and the only thing keeping them contained at that point is the tire.