Suspension set up is the #1 most over looked mod to make to any bike being Street or dirt. Suspension set up is more important than a modded faster engine. From the factory most street bikes are set up rather soft and have quite a bit of sag so the bike feels cushy and to make the brakes feel amazing. Here's my guide to setting up the sag on you'r 500. If you do this you will notice a night a day difference in the way it handles. The #1 misconception is that when you add preload to the springs forks or rear shock you are making the shock or forks stiffer. That is completely untrue. The spring rate is what controls the stiffness, all you are doing by adding preload is bringing the springs to their rate sooner. Ok so first things first.
To measure the rear sag this takes 2 people. Use 2 fixed points. In my picture I used the chain adjuster to the rib on the grab handle. Measure the distance between the two while the other person pulls the bike onto the side stand letting all the weight off the rear tire. Write that number down. For instance my measurement was 25.5".
Now sit on the bike with you'r normal riding gear in your standard riding position with all your weight on the bike and have the helper measure from the same points. For instance I had 24.5". The difference was 1" or 25.4mm. Ideal sag in the rear should be 30-35mm so I needed to take some preload out of the rear spring with a spanner wrench on the on the preload adjuster. I ended up with 32mm.
Now the front is the same concept. You can take a zip tie and put it around the inner fork tube snug and slide it down to the top of the dust seal/ wiper. I took my fork off and put an o-ring on the tube for future reference. With that 0-ring or zip tie all the way to the dust wiper sit on the bike with all you'r weight and gear in you'r normal riding position. Once again have your helper pull the bike onto the side stand taking the weight off of the front wheel. Measure the distance between the wiper and o-ring or zip tie. That is you'r sag number. For instance I had 49mm of sag. You want to be 30-40mm. So how do we fix that?
To add or subtract spring preload in out forks we need to make or cut the existing preload spacers. Atleast until someone makes new caps that we can adjust on the fly.
step #1 you need all the weight off of the front of the bike. I used tie downs from my garage ceiling.
Next is to take the caps off. Be careful doing so as the preload will throw the cap in the air if you arent paying attention.
Next thing to do is to make new preload spacers. You can use either PVC pipe or make them out of metal. The stock ones are plastic. They need to be 1 3/8 od. The stock length of them are 5 7/8 = 149.26mm. I made new ones out of PVC that are 10mm longer =159.26mm so I added 10mm of spring preload to the forks which put my sag at 33mm. Keep in mind the length of the preload spacers will be different for rider weight. I'm 135lbs. I do not recommend making them over 20mm because you might coil bind the springs and thats no good.
put the spacers back in and tighten up the caps and re measure. You may have to make different length spacers a few times until you hit the correct number. The bike feels stiffer on the bumps which i'm fine with but it does not dive nearly as much and corners great " not that it didnt before" but it's better now . I hope this makes some sense and helps you guys out.
In time Racetech will make different springs and emulators to control the dampening for different rider weight but either way you will end up having to set the sag.