2003 yz125 sss swap

I got the front end on. I used my front wheel for the 125. I have a newer disk I want to swap over. I want to ride it and be sure it works ok. But then take it apart and rebuild the forks and put new steering stem bearings on. The ones are shot and real rough. I will also buy new fork guards. He gave me some super beat ones. I also need to order a few bolts.

When I look at the axle against my 03 one it is the exact same. When I put the spacers up against my 03 the right looks the same the left looks the 1mm shorter like it says to be.

I did a little research. Says the axles are supposed to be different between my 03 125 and 07 450. It says the spacers are the exact same part numbers though which seems weird because people say you need to grind 1mm off the left one which the two I have the 07 one seems a touch smaller. I think maybe I just try to order a new axle?

One thing I found also I am using my 03 wheel. It has the same part number for the hub but the bearings are different. I have a wheel that is from a newer yz that has the same bearings as the 07 450 I will try. Maybe it’s a bearing issue.


Bought a new axle off eBay. Hopefully that fixes it. If still does not work I may buy some aftermarket spacers because you can get them for 19.99

Thanks for the info. I believe it is an axle issue or a spacer issue or a combo. My only thought is the hub is the same but I show different part numbers for the wheel bearings. That’s why I thought it was maybe that.

Well it’s all together until I take it back apart. I wanted to go put around the track and see how it is before I do rebuilds and new bearings.

Why does this always happen to me. Mis read the manual and had my torque wrench at 40 Nm and not 28 nm. Left hand drill bits come in so handy. Harbor freight has a set for like 5 bucks. Has gotten like 3 bolts out.

Got the forks apart to rebuild. The seals and bushings came in so I need to get them cleaned up this weekend and back together.



Also got the new steering stem bearings in. Got the old one off tonight. I was not sure how that would go but it was not too bad. Wear your safety glasses tho because I was chiseling the lip and a piece broke off and flung across the garage.

Gosh holy cow got the steering stem races out. The bottom came out with about 10 min of pounding. The top on the other hand sucked. Nothing happened after 1hr of pounding. I tried cutting it with a dremel nothing.
Then I read on thumper talk to use a pipe then chisel from the top to make it tight then hammer from the bottom. I did not have a pipe so I used a socket and an extension. Worked in like 10 min awesome.


I also figured out the axle. It is the smaller one. It is now on order. Weird because it is not supposed to be. Guess the guy i bought them from did not know what he had.

Well it’s all done. Screwed up my 03 hub. Stripped out a rotor screw and did a bad drill and screwed it up. Had to borrow my old 08 450 front wheel back from my buddy. Got the oversized disc on and it all bolted up. Just need some new grips and to check the spokes. Can’t wait to try it out. Just sitting on it and bouncing up and down it feels way better.

Oh I figured out the forks have to be 07 250 forks. They take the older fork guards but have the newer axle.