Manny hit the nail on the head (assuming that the sag is properly set with the right spring for your weight). The pull rods are pretty easy to make if you have access to a mill or a GOOD drill press with a milling vise. I have used aluminum bar stock before, and while I don't have the brass inserts in the holes, or the fancy writing on the side, I have never had a problem with making my own pull rods. The most important thing is that the holes must be in PERFECT alignment with one another. The simple way is to weld the two pieces of bar stock together, drill the holes, then finish the pieces as a set, with the last step being removing the welds (If you can weld aluminum, or have a friend with that tallent and equipment). A more difficult solution is the drill the first hole, bolt them together, drill the second hole, add another bolt, and finish the two pieces as a unit. Not as exact, but if you are carefull, it will work.
As I mentioned, I have made several sets of pull rods for my vertically challenged friends, all without any problems (except that one guy who forgot to tighten the bottom shock bolt, and when it backed out, it cut one of the pull rods in two
)
As a note, one of the local Kawi dealers sent an new KX500 owner my direction, as he was unable to get his suspension working. It turned out the guy only weighed 135 pounds. As one would expect, the 5.6 rear spring was a little
too big. Since I have a few extra rear springs, we set the bike up with a 4.9 rear spring (yes folks, that's a 4.9 off a kx250), that brought his rear sag to 7/8 inch static at 4 inch race. Just perfect. He no longer rides while doing a hand stand on the bars. Also, he can't be much more than 5'4", and with the right spring, has no interest in lowering the rear of the bike at all.
Good luck
Rick