Yamaha DTXpress/DTXplorer/DTXtreme

I just purchased the DTXpress used for $600 which was a fairly good 
deal, but I bought the older version that doesn't have that extra bar 
in the back for additional support. I have the bar that holds the 
toms and everything, but I have noticed in photos online of the newer 
version that there is a similar bar below that that seems to keep the 
entire rack sturdy. I am looking to see if anyone here knows where I 
can either buy that bar, or what part I could get that would get the 
rack to be a lot more study, especially if I am taking it on tour.
Thanks!
-Sam