97 KDX conversion to KX125 USDs

[vaderoni]

Ahhhh it's nice to see this website again, apparantly I haven't logged in since 2010

Time progressed, I've since graduated highschool, dabbled in buggy racing until it became too expensive, and recently sold the buggy to purchace bikes so that I can share the glory of riding with friends. Bike of choice? Why KDX's of course! So now my garage holds a '97 220, a '00 200, and a '04 220 (got myself a Pumpkin 300 too, certainly a step up from the "comfortable" ride of a KDX).

Anywhoooo, I'd like to swap a KX125 front end (unsure of year) that came with the 97 onto it. Before I begin, I have a couple questions:
The seller told me that the whole assembly will swap over (steering stem included) if I take out the bearing race on the top of the KDX's frame and put the KX one (which I have) in. Is this true?
Also, is it worth it to swap calipers too? Seems easier to just use the front routed one on the KX and just swap levers...

Here's the objects of interest




Unrelated, but if you look closely you'll notice there's no kickstand on the 97, anybody have one I could buy off of you? Or a place I could find one cheap?

[Julien D]

Nope, the KX stearing head bearing will not fit in the KDX frame. You'll need to press the steering stem out of both lower triples, and use the KDX stem in the KX lower triple. The upper tripple then needs a bushing made or found to take up the slop there. check some of the recent swap threads in this forum for all the info you could want. Oh, and welcome back!

[KarlP]

Look here for why Stems have to be swapped or something else done:

http://kdxrider.net/forums/viewtopic.ph ... highlight=

"The job is done, and what an improvement!

I took a slightly different approach from the usual, though.
I went over a buddies house who has a 20 to press and tried to push the KDX stem out of the KDX TT. Nothing doing, I was going to bust something before that thing moved.

The problem is that you can not get a top bearing that has an ID that matches the KX stem and an OD that matches the KDX frame. The two diameters are too close together to get needles in there, at any point I could not find one.
I had a new bearing "pocket" made that allows me to use the same bearing at the top on both bikes. I cut the old one off the KDX and welded the new one on. I found a bearing that does have an ID that matches the KDX stem and the OD matches the KX frame. I've ordered it and I'll post the number when it comes in. This will let me mount the KDX forks on the old KX, and switch back easily when and if I want to
If I could figure out how to post a CAD drawing or even a copied to Word image I'd post the drawing of the bearing pocket.
Because of alignment issues, I did not just cut the old bearing pocket off the KDX frame. I cut the walls of the pocket down then carefully ground it the rest of the way to the bottom of the pocket, but did not grind on the bottom of the pocket. This came me a reference surface to get the top and bottom bearings parrallel. If you look at the bottom of the pocket where that top bearing goes there is a through hole that the stem comes up through. The bottom of my new bearing holder had a edge that engaged that hole and made the two bearing concentric.

All worked out real well. I'd like to post a drawing of the bearing pocket. Any Ideas How?

Karl

[SS109]

Guys, don't forget that there is one KX that will bolt right on with no stem swap, the KX500.

[factoryX]

Good luck getting a pair, and at this point with I would go as modern as possible. Suspension has gone a long way in the last decade.

[Julien D]

Indeed it has, but mostly for MX. An older set of 43mm USD's work great for trail duty. Really just about any mx fork from 90 + and even some older conventionals are quite an upgrade from the stock KDX units.

[SS109]

Indeed it has, but mostly for MX. An older set of 43mm USD's work great for trail duty. Really just about any mx fork from 90 + and even some older conventionals are quite an upgrade from the stock KDX units.

Yep. I know my old '96 KX forks are awesome for trail riding.

[vaderoni]

Alright folks, thanks for the replies

Stayed up until almost 3am working on the bike last night and got thus far:





Until I realized that the seller was blowing me some smoke about that bearing race swap... the KX one is too big to fit the KDX head tube. Great; so I did a little late night research and have decided to have my stems swapped by RB. Left them at the post office about an hour ago, and now I shall wait with eager anticipation

[Julien D]

Yup, we knew that already about the bearings. RB will set you up.

[turtle]

RB just did mine. No fuss no muss. And they came back packaged well enough to withstand WW III

Fast too.

[vaderoni]

No joke about that packaging, good/fast work too

Just picked it up from the post office, will continue swap-a-lopping as soon as I have free time.

Excited? Yes

[vaderoni]

Grrr I should have updated this sooner, but the swap was pretty much done last week. Now it's time to tune suspension and possibly change out seals. Oh and the rear linkage has a tiny bit of play when picking up the wheel, guess those swing-arm bearings need a look.


I was going to post a quick question regarding the fuel system, but it got a little long winded to be on topic so I moved it elsewhere.

[Tedh98]

Looks nice, but you are going to want to route the brake line on the inside of the fork so it doesn't get snagged on something.

[rbates9]

Looks nice, but you are going to want to route the brake line on the inside of the fork so it doesn't get snagged on something.

+1

Also you will want to clamp the line to the fork guard so it will follow the wheel up and down.