what is this?

[chrisr65ls]

recently found this photo of an R65LS with this unusual brace on the side.
What is it and why would you need it?

[fastcataz]

A bolt on frame brace. Used to be a fairly common bolt on in the 80's.

[nhmaf]

That's a frame brace that were typical of what guys (and gals) put on their racing airheads.  I think that San Jose and a couple other mfgrs of fork braces offered these as well. Stiffened up the frame a little bit, but I don't think nearly so much of a difference as what was claimed.   Still, they aren't often seen anymore.
They aren't "mechanic friendly" as one has to take them off to remove the air filter assembly/get at the starter, etc. without pulling the tank.

Pretty sharp looking bike, though !

[Altritter]

Double-rider's horn button? (Meine Frau has one on the passenger side of our cage; Gott sei dank, she won't double up on my bike!)