KX Forks On The 300

Made and installed the spacers with new bushings and seals. I used steel for the spacers for two reasons. Didn't have any aluminum on the weekend when I started and I didn't much like the idea of aluminum as a spring seat.

I planned to use the KX triples. The lower has two clamping bolts per side and the upper has rubber mounted bar clamps.

Got the stem out of the KLX triple by running a #8 tap into the roll pin, driving in a screw, grabbing it with the vice grips and whacking the side of the vice grips with a hammer. Took 4000 psi on my press to remove the stem which works out to about 14000 lbs. The KX stem came out with less than 500 psi.

There's a problem with using the KX lower triple. They use the same lower bearing but the bore in the KX triple is about .010" bigger than the KLX. The KLX stem is a constant diameter from the bearing mounting area down while the KX stem is bigger where it's pressed into the triple.

The upper bearing on the KX is bigger so the stem is too big to use with the KLX upper bearing. I don't think a 28x47 tapered roller bearing that would mate the KX stem to the frame is available.

My lathe doesn't do American threads much less metric so I can't mod the stem. My options seem to be, until I can get to a real lathe, Use the KLX lower and stem or use the KX stem with a 28x47 ball bearing for the top.

I don't believe that bearing is an angular contact design but the only axial load on the upper is the preload you put on to take the play out so I think it would hold up.

Any thoughts?

What year forks and triples are you using?

Why not bring the KX stem to a machine shop and have then do the work?

Or, for the time being, just use the KLX triples if your forks are 43mm.

Ride on


If you have the 43mm KX forks, another more expensive option is to use BRP clamps for a KLX300. I have them and the lowers have two pinch bolts per side but the uppers do not have rubber mounted bar clamps. I have not done the KX fork swap, yet....

They are '94 or '95.

I'm too cheap to pay a guy to do the machining.

If the ball bearing doesn't work out for the top I'll stick with the stock lower and the KX upper. The only requirement for the upper is a thin spacer since the bore is bigger.

Seems to me I read here about someone using the KX lower. Guess I'll do a little searching.

Found a spring from a seat belt retractor .0055" thick. Cut a piece to length, clamped it around the stem with a hose clamp to get it started and pressed it in.

Worked like a charm.

Goes to show why I never throw anything away.

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