Adjust your shocks. I had the same problem. I also run 44psi single and 46-48psi 2up, but I have Metz on mine. I have a 21" spoke wheel up front and use 36psi. Tim

 

I had the same problem riding with my wife who's only 110 lbs. while shocks were set to the easiest setting.

I bought the HD shock wrench. It's cheap and easy to adjust. i'm keeping them in position 3 of 5 right in the middle and been ok so far whith one or two of us on. No more bottoming out.

 

between the wife and I we weigh about 320. i have mine on the hardest setting (for an 1200r) and we still bottomed out. pressure about 38 is ideal. the ohlins shocks with progressive springs will eliminate this problem, but will need to adjust down when riding single, unless your spine likes being hammered...