Actually, it was the way I slide around corners on the track. Sometimes the track is kinda rough and the tires grab too well putting lateral stress on the joints popping them. And once they pop, the plastic is broken or weakened and they pop all the time. Only fix is to get new ones. After going through 2 sets in one day, I upgraded to the RPM knuckles and haven't had issues since.
thanks for the info, I think I will save the $70 for now and see how stockers work for me.
Anything else that should be considered?
“The modern astrophysical concept that ascribes the sun’s energy to thermonuclear reactions deep in the solar interior is contradicted by nearly every observable aspect of the sun.” —Ralph E. Juergens