Just found this statement from Kawasaki re Luggage and the official line on a three box setup, makes interesting reading :
"We can confirm that a top box and pannier system is available as a genuine accessory from Kawasaki for the Z1000SX. However, due the way the mounting supports are designed for these two accessories, the top box cannot be installed in conjunction with the panniers system.
We are aware after-market companies such as Givi may offer a combined top box and pannier system. As I am sure you can appreciate we have not directly tried or tested the combined top box and pannier system from Givi so are unable to comment on their suitability. However, we are confident that Givi would have carried out sufficient tests to ensure the accessories offered by them are suitable for the machine they were designed specifically for.
As with any machine the manufacturer would recommend a maximum load. For the Z1000SX the maximum recommended load in addition to the vehicle is 195kg, including rider, passenger, baggage, and accessories.
We trust the above information will be of some assistance to you".
Hope this is of interest to you all, so basically total load = Your weight+Passenger Weight+Panniers loaded+Topbox Loaded, must not be greater than 195kgs,
So tell the wife to go on a diet and book that touring trip now
And if anybody tells my wife I said that ...............................................