Suspension swap question...... can anyone help me out?

[Watson777]

I have a 2006 KX 250 and also have a set of 2012 KX450F suspension sitting here. Anyone know if the 450 stuff will fit the 250 and if not if there is anyway to make it fit? Not sure if the 450 triple clamps would bolt up as I'd imagine that whole stem and all is much different. Any help is much appreciated! Thanks

[sandblaster]

Never tried it and my info is incomplete but I know that both forks use 48mm chrome and DLC OD.
The UPPER clamping diameter on the kx250 is 55.9MM and the LOWER clamping diameter is 59.2MM -
BRAKE MOUNT 102MM.
So, I'm wondering if you can just slide the fork tubes out of the 250 and slide in the 450Fs.
Measure the clamping diameters of the 450F forks and see how close they are to the 250's.

[Watson777]

Thanks, thats some good info to start with

[The Flyin Hawaiian]

I believe the top of the forks are smaller on the F. A simple shim may be needed.

[don46]

I've not actually done that swap, but I'm sure they can be adapted I've used 250f on the 450f chassis. look on the fiche and see if the bearings are the same (Ithink they are) then its stem length and as flyin say might just need a shim. The only issue I could possibly see is the offset, offset might cause you some problems on handling. if it was me I'd try it, couple hours and you'd know one way or the other whether or not they fit.

[giac76]

Hi, I use a set of front fork from a KXF 450 2008 in my KX 250 2006. they are 1,5 cm longer,no problem with the brake, only you need some spacer on the triple clamp, because the KXF's forks are smaller on the top. Later I can tell you the size

[Motorrad]

I used 2008 Kx450 on my Kx500... just needed a steering stem swap...

[J.ellwanger]

I used 2008 Kx450 on my Kx500... just needed a steering stem swap...

what steering stem did you end up using? if you dont mind me asking and what year K5? thinking of doing this since I have heard good things about it

[Motorrad]

Used a billet alum one from emig racing.  Cost $89.    Worth every penny

[J.ellwanger]

what did the stem do? lengthen it or shorten it?
 or...?

[Motorrad]

Made it so stock 08 450 clamps bolt on my k5 frame like it was from the factory that way.    Don't recall the specific changes

[motopunk]

 the k5 had always the smaller stearing stem bearings like the old 125 and 250´s ... in92 or 93 came the bigger diameter bearings to the 125 and 250 and still used in the actual 4-strokes... 
for a fork-swap you have to take the smaller bearings and it will fit without problems to the kx500.

for the swap of the actual forks to the older kx125 or 250´s you only need the right clamps to the forklegs .
if one fall in my hands i want to update my ´93 kx500 sfc with the newer forks.