I have no knowledge whatsoever on this subject ... but I do have access to a couple different engineering software packages.
We have a simple little Excel MOI worksheet that generated a .537 MOI with 2.0x.25 DOM ..
It generated .325 MOI on 2.0x.125 and .264 on 1.875x.125... for a total MOI of .589... in theory doubled tube is stronger correct?
check this thread out...
http://www.pirate4x4.com/forum/showt...+tube+strength