Interested in a Hybrid

[Frank ZX]

Hi,This is my first post. I have a 2001 YZ125 and a 1994 KX125. I'm very interested in building a KDX Hybrid. I measured inside each swing arm and the YZ measures 80mm and the KX is 84mm.
I don't see that big of a problem welding and milling the YZ swing arm, being I work where getting something milled is pretty easy.
Can anyone tell me how wide the KDX cases are where they mount between the swing arm?
If that don't work, I have also thought about using the KX swing arm in the YZ chassis.
Thanks

[scheckaet]

what year kdx are you talking about? pre 95 or post?
Or are you trying to stuff a KX engine into a YZ???

[Tedh98]

There are some measurements in this thread: http://www.kdxrider.net/forums/viewtopic.php?t=4546

[scheckaet]

and here
http://www.kdxrider.net/forums/viewtopic.php?t=8245

[Frank ZX]

It seems that roughly 10mm needs to be cut from the yZ swing arm.
I still think it possible. I would much rather use the 94 KX frame,but for some reason nobody recommends them?

[Tedh98]

I think the only problem with the '94 is the age/design of the bike.

I had a YZ 125 and wanted to use it for my hybrid. But I ran into this problem:
http://www.kdxrider.net/forums/viewtopi ... highlight=

I decided that it was too much work and too much of a risk in screwing up a nice bike if I couldn't make the swingarm work.

[Frank ZX]

Hi Ted, I read you post, but I'm still not clear in why you didn't go farther with the YZ than the obvious?
Filling the cavity with a weld seems to make the swing arm strong enough to make this work. I just discovered this site yesterday and I think I have made the decision to go thru with the swap.
Why can't you widen the swing arm some and narrow the engine cases too?
The only real problem I see is the double bearings on the YZ swing arm as you mentioned in your post.
Also,besides the age of the 94 KX, what's wrong with the design besides the suspension is dated?
Sorry for all the questions, just trying to figure this all out.
And last but not least, I may consider trading my like new '07 YZ250F loaded with goodies for the right hybrid. Just thought I would throw that out there.

[Tedh98]

No other reason than I didn't want to take a big risk. I could have screwed up a really nice bike that would then only be good for parts. And without any history or documentation of a YZ/KDX combination, I'd be taking a chance that the cost and time commitment would be more than I could afford. And finally, if I could have made it all fit, there might be a chance the end result wouldn't be as good as the KX/KDX combination.

I personally felt better going with the KX because I knew what to expect and I also knew that I'd have something to ride sooner than later.

Now if I had a bike that wasn't in such nice shape and had a way to get machining done for little or no cost, that would change things.

If you decide to use the YZ, please take lots of pictures and notes. I'm sure there will be many interested guys wanting to see that build.