The space between the frame that the luggage mount to and the fender is five inches on the shifter side. The space between the front attachment arm that runs to the footpeg mount and the shock absorber(stock shock) is one and one half inches, The clear space for and aft unencumbered is twelve inches. My gut says that the rotopax idea is not, but there is plenty of usable space for toolkitery. I was thinking of a row of MSR fuel bottles and tool kit. I will take pics this weekend and post any info that use all need. Given the lack of viable options, this rack fits the bill very well. I mean even if there were many viable options, this rack fills the bill very well. Now to find a five inch and seven inch box that dimensions out in height and width the same. Happy Trails sight is tough to negotiate when just searching boxes.