Bummer. Looks like the box you have on there will put the whole assembly well over the 7.5kg (16.5lbs) max load limit. The box + adapter plate alone might push you close and then there was the additional load of passenger leaning on the box.
I had the same rack on my old bike for few years, but I only used a small soft bag on it and only on longer trips. No problems.
Originally Posted by rms_z28
Looks like your rack is different than what is currently out there for the '08 and on. Notice the legs that mount to the passenger foot pegs in this picture
Probably because they later found out that the older form of mounting caused too much stress on the sub frame...
Probably. SW Motech has also dropped the max load limit on the newer and sturdier construction to 5kg only (including adapter plate + bag). So not much room for luggage within the limits.