Hmmm, I have an 06 KX250 and would agree that it needs a stiffer rear spring. I have .44's inthe front which seem to be good, but the 5.0 rear needs to be about a 5.4 or so as I weigh about 100kg's in riding gear.
Probelm is I have access to a 5.6 spring reaaaal cheap, but I'm worried that it will be too stiff. I ride a little MX and trail rides too, so I'm guessing I better keep shopping?! :bang:
Forgot to mention, I recently rode a KTM EXC200 that had a much stiffer rear spring fitted and it feels waay down in the front as the rear rides high and forces the forks to overwork.... so THAT's what I'm worried about buying the 5.6. for my KX.... should I be worried?
Hi John.
The 5.6kg will be too heavy for you. And while Kawasaki state that the rear spring is a 4.9kg, Race Tech have measured them and found them to be more like 5.3kg. This should be about right for you, or if your spring measures at 4.9kg a 5.2kg should be good for the type of riding you are doing.
Have you tried increasing your low speed compression damping?
Set your sag to 100 mm with the existing spring . Then check the ststic sag if it is between 10 - 20 mm the spring is in the right zone for you . Less than 10mm I would say it is too soft for you as too much preload on the spring makes the static sag # very small. Any more than 20mm it is on the stiff side for you .As there is very little preload on the spring .
Right on fellas, thank you.... I have to admit the stock spring (whatever rate it actually is?!) feels gtreat but the bike rides very low, and looks chopper like when I'm riding. It also has chopper steering traits (over steer then understeer) too if I don;t have my weight a long way forward. I set the sag at 100mm a few weeks ago, but I also think it may need doing again as the bike seems to be sagging again?! Will check and re-post the results.