Is there a bracket to hold the drag spar stable? A hole in the pad the spar rests on through which a hold-down bolt is inserted? Other ways to see if the root is misaligned if you rotate/move the wing support cuffs and swap the wings?

I've seen trailers that carry the left wing on the right side but it's typically to squeeze the pieces into a tight-fitting covered trailer. From memory, the old Niemi-type trailers might have been like this. They loaded from the front over the tow bar and the wings came out root first. So IIRC, the curved top surfaces of the wings had more clearance when carried on the opposite sides of the trailer. Actually, since the fuselage was carried facing backward, the wings were on the correct sides but the fuselage was reversed. Oh, well. It's been a long time. I remember a strap we sometimes used to support the spar stub as we bent over to remove it from the trailer and then walked it out carefully.

From experience, carrying a fiberglass glider on a Schweizer trailer has one added risk: because the spar stubs are so much longer than on a Schweizer, they can overhang the front of trailer enough to limit how tight you can turn with the tow vehicle. Obviously this depends on the specific geometry of the trailer but in our case (a 15 Meter Diamant HBV on a Schweizer 1-26 trailer--don't ask), every time we made a tight turn it threatened to punch a hole in the car's sheet metal and/or damage the tip of the spar stub. Good luck.

Chip Bearden
JB