KDXRIDER.NET

Cool diagram, though many recommend 4mm nowadays.

Agreed. I didn't feel like re doing the pic. It should day anything above 0. :)

Ha. I hear ya.

Guys, can somebody explain me this preload spacer, which is the difference if l add more space between top and spring, in this case 10mm, or maybe i didnt understood this picture? Under number 7. I dont get it, l need to put something between, to get more stiffer fork, if l am correct? I need some explanation because l want to change the oil in my fork, and to get stiffer fork more, with the oil 10w l think i will get stiffer fork, before was 7w. And why l need to cut the spacer? If l add for exampe 4mm of washers( washers is like example)

The preload spacer is there to take up the space between the spring and the fork cap. With no spacer, you spring would have space to simply bounce around inside the fork. The size of the spacer adjusts the preload. If you go larger than the empty space between the spring and fork cap you will compress the spring a bit when you re assemble the fork. The amount of preload is different for each rider and rider style. Think of the rear shock. If you turn the preload tighter, you make the spring shorter and you are pre compressing the spring. It won't make the spring any stiffer but it will give you the springs rate quicker. It will be less supple on light bumps.

#7. The spacer in the picture fits in between the spring and the fork cap. That measurement is "A". A spacer with the measurement that equals A would offer 0 preload. Anything you add to that measurement and then to the spacer size you use, is MORE than the space can fit. So to make it fit, the spring must be compressed some. That is the preload. The amount you have to compress the spring in order to fit the spacer you cut.

To get a stiffer fork you need a stiffer spring. Thickening your fork oil will not give you a stiffer fork. Just a slower one. It will take longer to compress and longer to rebound. as the thicker oil is forced through the valves.

Cutting the spacer. For example. I purchased brand new springs for my weight and they were about 1" longer than the factory Kawasaki Springs from 2000. To keep my preload correct, I had to remove that 1" from the spacers. I also wanted my forks to not react right away over light bumps so I actually reduced my final preload down to only 3mm.

So in the end....

I bought springs for my weight.
Found my "A" measurement.
Cut a PVC spacer to A + 3mm
Changed my fork oil to 7w to slow my rebound speed.
I then backed out my compression settings to compensate for the thicker oil.

I hope this clears it up. If not, you can simple jump in on a fork and look at it. Buy a length of PVC for 3$ and try out different sizes to see how it works.
It is not hard at all. :)

skraMnoR wrote:Buy a length of PVC for 3$ and try out different sizes to see how it works.
It is not hard at all. :)

Ron - I've been following this discussion. Good explanation and chart above. This ^ is the best part - it's very easy and cheap to adjust preload with various lengths of PVC. For my KLX, I wanted about an inch of preload so I bought a 1" diameter PVC coupler (which is about two inches in length) and simply hack-sawed it in half for two spacers.

Now its much more clear, its not hard, but clear explanation its much more precise, l will not change my spacers,l will add 10w and mix with 5w, i cannot find 7w oil now, but of course the same oil, and add 5mm of bushings, i see what will happens, l think l will be satisfied, because l never change oil inside, maybe is old, maybe was 5w, one and half year i am riding like this
Thanks for this posts, l appreciate this