How to swap 89 KX250 RSU forks to USD...

[Micahdawg]

Does anyone know if it is possible to swap out my conventional 46mm forks on my 89 KX250 to an inverted design? I ask because I'm aware that the KX500 shares a LOT of parts with my 89 KX250 and almost all of the newer KX500's have inverted forks. Is it a matter of buying a set and clamping them to my triple trees or can I swap the KX500 triple trees with forks over?

Could I just clamp on ANY 46mm inverted forks to my triple trees? Any help would be great.

Micah

 

[Buckholz]

Those forks got rave reviews that year. I had an '89 YZ with USD, and they were not nearly as good as the 46mm ones on the Kawie.

Why switch? Save your money for a new bike!!!!!! Or spend the money on racing and fresh tires. Both will help you more than replacing forks that were great in '89

 

[mtk]

I helped a friend put inverted WP forks on his '83 Maico 250.

We pressed out the Maico stem and the KTM stem (the WP forks were from a mid-80s KTM 250) and had a machinist make new stem that copied the Maico dimensions for the bearings and length but also fit the KTM triple tree. Then I machined a set of steering stops for the lower stem and bolted them on. We pressed it back together and bolted it on the bike.

But I agree, don't bother. We did it because he had the parts, the Maico has a front drum (the KTM had a floating disk), and it was cheap. And it's a Maico, i.e. a collectable machine (the old parts are in storage).

 

[ETS]

I agree with buckholz, those are great forks. Not just great forks back then but they are still competitive. They probably just don't look modern to you? Anyway, any of the forks should fit as long as the triple clamps come with the forks. I don't think the frame changed up on the steering head. Just don't swap a set of 90' to 96' forks and expect much of a difference and you'd be going backwards with the 90' fork. For sure you couldn't just clamp 46mm forks in your clamps because your triple clamps hold the 46mm fork tube and inverted forks hold the larger diameter out fork tubes.

 

[Micahdawg]

I rebuilt the forks completely this past year, but I have to use these ghey looking fork boots to keep them nice and sealed up. So yes, it would just be a cosmetic change.

I all about selling the bike, but I haven't had any luck so I got thinking that some inverted forks + newer front fender might freshen the look up a bit. The power is pretty nice and aside from the dated ergo's.......the rest of the package feels and looks pretty modern. That is, aside from the ghey looking forks.

http://dirtrider.net/forums3/showthread.php?t=108143

Micah

 

[ETS]

You know a front number plate from a 96-98 RM250 would spruce it up a bit. Put some seal savers on at the same time and it would look good for a lot less money. My riding buddy had a 89' KX and it was a fun bike to ride.

 

[Micahdawg]

Few things. I actually thought about the number plate from an RM, but (1) I wonder if it would look decent or not and (2) would it adequately protect the seals. These seals seem finicky. I rode a couple times with no boots just so I could keep an eye on them and dirt immediately caused them to leak.

Have you seen a early KX with the RM plate? I'll have to consider that.

The only other issue I have with these forks is they don't seem to extend up fully. Almost like the springs are a little weak. Know any good source for cheap springs?

Thanks for the info. As you can see I'm pretty torn as to bail on this bike or just keep it for a little bit longer.

Micah

 

[Micahdawg]

For anyone that cares...I bought a 97 RM number plate and will be ditching these ugly fork boots. I'll post before/after pics when all the parts show up.

Micah