By what we hear, the 1/2" is about typical, which is plenty if properly installed. The guy in Hawaii was hitting at first, and as I said above, we flipped the bolts and lengthened the struts & got room that way. Keith was good to point out that the muffs are forward of this area, and the pipe at that bend going up is the only close spot.
With the poly/axle mounts being at 27"+ apart, that keeps the bends on the bar right at the edge of the poly. That keeps the bar right on center of the rear, and doesn't move under turns or launches. The tighter the clearance, the more important the width becomes on the axle brackets. Again, follow directions & put them at 27" & 99% of the time all is well.
THANKS!
PS-- Keith, got any good pics of yours? I got a decent one from the rear, but it was dark & kinda grainy looking. Think I got one video too, but I was too far away to get it good.