UPDATING KX500 SUSPENSION.

[Sandblaster]

You might very well be right.
I do have one more thing to try tomorrow....
It may be the easiest of all solutions
I'll let you know...

[Sandblaster]

Well, I had two awesome idea's last night.... both of which were EPIC failures...
What would be cool is if we could find a tapered roller bearing with a d (ID of bearing) of 28mm and a D (OD of cup) of 47mm..
SKF no...
Timkin no...
FAG no...
NSK no...
AST no...

Ok, I'm tired of looking at tapered roller bearings.
Seems the Min D in 52mm which is 5mm to STINKIN big...

Another idea is forming

[Sandblaster]

angular contact bearing

http://www.nationalprecision.com/librar ... 1-No1.html

angular contact bearing.png (40.7 KiB) Viewed 11117 times

What does an Angular Contact Bearing offer a designer that a Radial Ball Bearing doesn’t?

The easy answer to that question is additional thrust load
capacity. So let’s take a look at how a thrust load affects a ball bearing. Here are images of a standard bearing (left image) and an angular contact bearing (right image).

The amount of thrust load a bearing can carry is directly
related to the contact angle, shown in the drawing. Standard miniature bearings, for example, generally have contact angles of 9-25 degrees, depending on the radial play. Angular contact bearings are available with contact angles from 15 to 40 degrees.This allows them to carry a much higher thrust load.


A radial ball bearing is designed to have the load primarily in a direction perpendicular to the axis of the bearing, that is, directly toward the center of the bearing. Depending on the radial play of the bearing, some thrust loading is possible.

Angular contact ball bearings also have raceways in the inner and outer rings that are displaced with respect to each other in the direction of the bearing axis. This allows them to reduce the compression loading on the balls while being loaded in the axial direction as well as in the radial direction.

[Sandblaster]

Here's a adapter I was thinking about..

ADAPTER.JPG (48.29 KiB) Viewed 11114 times

This would allow for using all the factory bearings from the 07 KX250F.
I'm not sure about the addition of 5/8" of material.
It may be too much for the steering stem even though the 07 KX250F is longer then the KX500 stem.
But, I'll have to do some careful measuring and see what I can find out..

[Sandblaster]

After a few more measurements I came to the conclusion that the threads need to be about 1/4" higher up the stem or we need a completely different adapter size..

ADAPTER 2.JPG (41.51 KiB) Viewed 11109 times

Then again... perhaps I could turn some smaller diameter threads just above the where the existing threads are...
Probably not as I don't think the stem is long enough but it's worth checking... After all I've gone this far..

[Sandblaster]

Long story short, You can use whatever kx500 front end you want with the corresponding triple, front axle, front brake, and wheel.
With a steering stem from EMIG you can use whatever you want from late model KX's
http://www.emigracing.com/

[Sandblaster]

Update 8-26-15

If you use the 97-04 KX500 triple tree's in your whatever year KX500 you can then use up to 2015 KX450F forks as they drop right in.
You will need the front axle, axle spacers, and front wheel, but I think the front brake caliper should bolt right in

[socalmx348]

I'm new to the forum and want to jump on this bandwagon. I have been in the process of restoring a 1995 KX500 for about a year and wanted to go with more updated forks. I have done this in a few different ways, each of which costing more and more money. Here is what I have so far.

First, was wanting a set of the larger diameter forks. Hard to find, but I did some research (part number by part number) and found that the 1996-1997 KX125/250 have the same forks as the 1997-2004 KX500's, with the exception of one single piece that is on top of the internals. It appears to be a spacer/larger nut and does not appear to have any functionality. Those forks are available readily online.

Second method to obtaining the larger forks was the easiest, I met a guy that had a set of 2003 KX500 forks with triple clamps in excellent condition and got them for a great deal.

The final method, and most expensive was swapping the entire front end to a 2015 KX450F. Here is where I hope someone can benefit from the research I have done, since there doesn't seem to be much on the internet. I picked up a set of the TAC AIR forks from eBay. Then I found that the triple clamps from the larger diameter forks on the KX500's will allow the new TAC AIR forks to slide right in. Since I wanted black clamps I picked up a set of 2013 KX450 clamps. In order for them to fit the frame properly you need to put the stock stem into the clamps which will allow you to use the stock diameter bearings. Newer KX's have steering stems that get fatter toward the top, therefore will not fit the bearings into the frame. Next was a front brake caliper. 2006-2016 are all the same caliper. The difference here is going to be the 2015-2016 have oversized rotors and require the larger bracket, and obviously the larger rotor (270 mm to be exact). Hubs for the bikes have changed throughout the years as well, with 2009-2016 hubs all being the same.

Using the 2013 triple clamps vice 2010-2012 also allowed me to use the 2013-2016 front fender and number plate. The mounting for the number plates are different on the clamps themselves, and the fenders and number plates match up by their shape. Mixing and matching may look weird.

Hopefully this is useful. Apologies for it being so wordy, but I definitely want it to be helpful.

[Sandblaster]

Hello and Thanks for the info!
A lot of what you wrote we have documented.
Didn't know about the front brake rotor... Good information.
I know a guy who bought a 08 KX450F fork set and he is sending them to me for a full rebuild.
I plan on toying around with some goodies while it's here

[Sandblaster]

The next step is building a KX450F shock to fit the KX500.
It won't be easy but it is possible.
The most difficult thing is moving the reservoir...
Yeah, that will be a issue
And the clevis needs to be modified.

KX500 WITH A KX450F REAR SHOCK 101.JPG (83.53 KiB) Viewed 10551 times

KX500 WITH A KX450F REAR SHOCK 102.JPG (52.67 KiB) Viewed 10551 times

KX500 WITH A KX450F REAR SHOCK 103.JPG (75.38 KiB) Viewed 10551 times