phaltlines ballooning

[carlg1]

have any of you guys ever had this, my hpi phaltlines are ballooning on a speed run, any idea of what speed this happens, thanksicco:

 

[Crash]

wonder if foam broke/split

 

[carlg1]

wheels and tires are brand new, think it just the actual speed doing the tires, trying to find out a rough speed when this happens, running 19/47, h/s 3 speed and a drag modded piccopiccogirl