I would have thought a crosser and the rack to carry it, would have been a lot heavier than the tow bar was rated for and even if it was rated upto it, i'd have still been pretty nervous about it.
That prob weighs no more than 150kg. Same weight as 2 average men or 1 rather fat person. My guess is most likely an overestimate if anything. Is that really too much?
Just think the weight of a caravan pushing down on it when braking etc. This must put more strain on the tow bar than the x`er?
My parents do a lot of caravaning with a tourer and the average hitch weight should not exceed 75kg, usually my dad likes to drive with about 50kg on the hitch. Most of the weight of the van are on the wheels, and hitch weights are even less on a twin wheeler. Thats why i thought it might have been a bit too heavy. Especially as the weight is not directly over the point of connection to the chassis, and is quite a bit outstretched.