UPDATING KX500 SUSPENSION.

[moto939]

I had a new set of suspension from an '09 450, so the spring didn't really cost me anything (or that's what I like to tell myself), but take off springs can be found on the forums(TT or vital) for around $100-150 if you post a wanted add. Sometimes on ebay a complete shock with the spring can be had for cheap.

'06-09 450s ran a 5.5kg spring. LE models had the red spring, otherwise the rest were unpainted like this...



'06 and up 250fs 250s and 125s also ran the Ti springs ranging 5.3 down to about 4.7 ish. So a variety of spring rates are out there, but I find the 5.5 to be the sweet spot on 250s for my weight.


I'm down for a Guru link if there isn't too may hoops to jump thru to get one. Have an ETA?

[Sandblaster]

Contact Alex Ward at Crazy Al's Racing for the link arms..
208-249-7152

I'm on eBay looking for a spring

[moto939]

Two things to keep in mind....

First, the easiest way to verify the spring rate is by the color code on the bottom of the spring. 5.5 is pink 5.3 is yellow Don't know the rest, but it's a KYB thing whether steel or ti and you'll want to verify it before laying out the cash.

Second, you'll notice a couple plastic spring seats on the ends of the spring. These are a wear item, so make sure they are in good shape and have a spare set in your tool box ( # 1C3-22565-00-00). As they break down (and fall out eventually) you'll start chasing your tail with excess sag. Keep em fresh and the spring will stay consistent.

You can just see the paint dot in this pic.






I have to pick your brain about the 38mm air striker on a 500, but I'll start a different thread when I get a chance.

[Sandblaster]

Excellent info on the springs and the plastic seats..
I had no idea on the plastic seats.
I need a 6.1
None on eBay at the moment but I will keep an eye out...

On the 38mm Air striker... it's good for 1 hp to the rear wheel on a totally stock K5

[moto939]

5.5 is as heavy as you'll find in a Yamaha Ti spring.....you may have to search for a RCS spring.

[Sandblaster]

Or... I'll have to go on a huge diet..... Probably not

[Markee757]

I'm trying to find parts to rebuild my 92 shock. What's the difference in my shock and the 97-04??

[Sandblaster]

You can bolt right on 89-04..
The difference in the 92 and the newer at a minimum is the seal head size. The 96 and older are smaller.
Here I'm guessing a bit..
I think the bladder size is smaller...

[Zerofear66]

If you have the 97-04 KX500 triple clamps then the world is your oyster..
You can install 06-16 KX450F forks right in.
You can even use the 2013 YZ450F forks

Sorry for the dumb question. I have an 03 KX500
Will the 2013 YZ450 forks "slide right in"

Thank you!!!

[Sandblaster]

No questions are dumb that can help you save money and time..

I have a customer we built a engine for and he is running a 2013 YZ450F fork.
Here is his comment:
For those who have ridden with that SSS fork....its unbelievable when set up right! P L U S H!!
He said the tube went right into the 97-04 KX500 triples.
He is using a YZ wheel and brake.

Generally speaking, the Chrome diameter follows the outside clamping diameters.
IF that is true, the seals for the chrome tube 17D-23145-00-00 fit 2010-2016 YZ250F and YZ450F so it stands to reason that 10-16 would all bolt right up.
However, the only year I have actually measured is the 2013's and... the 2006 YZ450F.
What you need is something close to the following: UPPER 53.8MM - LOWER 58.9MM
The 2006 UPPER 55.82MM - LOWER 59.06
Or, .080" difference between the upper KX500 and the 06 YZ450F forks
The lower is .006" difference.

Here is some info from another YZ fork guy.
Just some info...SSS forks and clamps
All have 59mm lower clamping surface
'06-'09 450f 56mm top
'10- current 450f 54mm top
'06-'12 250f 56mm top
'13-current 250f 54mm top
two strokes 56mm top
Hope this helps anyone planning a fork swap.
I'm installing new '09 450f forks on a '01 500. Needed to machine out the stock KX top clamp to 56mm to fit these forks.
The fork spacing of the KX clamps is slightly narrower than the YZ clamps, so I'll have to fiddle with the wheel spacers a bit. Otherwise it should be a clean set up.
I own a 2016 YZ450FX, so did some measuring and research before I even bought a 500 and learned that the Yamaha stuff is real close. I used a caliper to measure the diameter of both sets of forks, but since it is just a cheap Harbor Freight caliper, I doubt it is exact, but I figure the difference in measurements between the two forks should be pretty close. The top clamping area was on a difference of 0.01 mm, while the lower was 0.3 mm difference. Just used the stock KX triple clamps, and the YZ stuff slid right in, also used the front wheel and brake from the YZ