KDXRIDER.NET

***EDIT by KDXGarage due to someone editing a post to be blank. There was a question before rexemouse's post. He replied to it in this post.***

I built an 03 kx hybrid. It's a fabulous bike. I have the Clarke tank and it required very little modification, 15 minuted with a heat gun and the blunt end of a screwdriver.

I have an 01 hybrid (same frame as the 99) and love it as well. Either of the newer ones is a good choice, little more aftermarket support for the 03 of course. Benefit of using the 99 is you already have a front end, the front changed between 02 and 03. But if the 03 is a roller then that's the way I'd go FWIW. Get it properly sprung and you'll wonder why it took you so long to build one!

The 2003 + stem is 6 mm taller.

The steering tube of the frame and the steering tube are 6 mm longer. If you want to use 2002 and older lower clamps, they will have to have a 2003 + stem installed.

EDIT by KDXGarage due to someone editing a post to be blank.

Not spread but height. The fork legs have plenty of adjustment to handle it.

The offset changed as well on the 03. If you have a roller thats still the better way to go IMO

Read up on the differences in older posts. There are a lot of posts in the past decade or so on this site.

The 03 has a lot of unique parts, like the swing arm and linkage system. The roller I started with was really rough, and I had to replace some on these unique parts. They were a struggle to source, and extra not cheap when I found them.

Regarding forks, one advantage of the 03-05 is that kxf forks and triple bolt right up. Assuming you like showa TCs.

Definitively take a look at the builds on this site. I referenced these daily when building my two hybrids.

EDIT by KDXGarage due to someone editing a post to be blank.

The stem is longer hence the steering head also sits higher. Learned this when swapping '02 triples (22mm offset) on to an '03 KX250 (stock 25mm offset) which is the same basic setup as the KX125. Had to swap the '03 stem in to the '02 triples to makes it work.

They are not 20 mm offset. You might find the offset in some old Motocross Action magazine website articles.

I want to say they are 22 or 23.

The outer fork tube diameter changed a few times even though the inner tube was 46 mm.

There were three upper KX125 / KX250 clamps for 46 mm forks, (1996 - 1998 , 1999 - 2000 and 2001).

There were three lower clamps (1996 - 1997), then 1998 - 2000, then 2001 with the tapered stem.