Exhaust keeps getting loose
 

I just installed my Tab exhaust (no baffles) about a month ago and the bottom pipe seems to continue loosen up when i ride. Im using the chrome clamps i had on my stock exhaust. The top exhaust hasn't loosened up once. Finally thurs before i headed out on a four day road trip i used locktight. The bolt seems to be tight on there but the pipe is loose. Its almost like it would need a bracket to support it.

Any ideas? Something so simple and i am stuck. Im thinking of cranking it even tighter but it was pretty tight on there. Could the clamp be stripped even though it still tightens? Im thinking that the other side of the bracket might be stripped??

Are you using a torque wrench and tightening all fastners according to the service manual? Muffler clamps require 40 ft/lbs.