KX Guru Racing

Posted: **Wed Jan 14, 2015 2:20 am**

Not much to show today...
Just a little clean up...

: OEM-CYCLE.COM 2007 KX250AF BUILD 122.JPG (123.71 KiB) Viewed 9465 times

Posted: **Sat Jan 17, 2015 5:36 am**

Didn't get a lot done in the last few days but we did get the frame rails removed from the holders..

: OEM-CYCLE.COM 2007 KX250AF BUILD 123.JPG (240.84 KiB) Viewed 9456 times

: OEM-CYCLE.COM 2007 KX250AF BUILD 124.JPG (247.47 KiB) Viewed 9456 times

Posted: **Wed Jan 21, 2015 6:09 pm**

On the AF conversions, one of the problem area's is the cradle.
A lot of guys have trouble with the down tubes cracking around the engine mounts.
Just for grins, I wanted to see how Honda does their Y section and was a little surprised at what I found.
In this next pic, look at how little material actually goes up inside the main tube..

: OEM-CYCLE.COM 2007 KX250AF BUILD 125.JPG (55.75 KiB) Viewed 9449 times

In this pic, look at how thin the tubing is.
The wall measures approximately 1/8" thick.

: OEM-CYCLE.COM 2007 KX250AF BUILD 126.JPG (71.47 KiB) Viewed 9449 times

Posted: **Thu Jan 22, 2015 1:19 am**

Getting closer....

: OEM-CYCLE.COM 2007 KX250AF BUILD 126.JPG (155.17 KiB) Viewed 9447 times

Just a little bit more trimming...

Posted: **Thu Jan 22, 2015 5:35 pm**

Almost ready for weld..

: OEM-CYCLE.COM 2007 KX250AF BUILD 127.JPG (64.89 KiB) Viewed 9444 times

: OEM-CYCLE.COM 2007 KX250AF BUILD 128.JPG (52.5 KiB) Viewed 9444 times

Posted: **Thu Jan 22, 2015 5:45 pm**

So... My buddies idea is confirmed!!!
You can use the cradle from a 01 CR250 in the KX450F frame.
It takes a little grinding and fitting but it fit's amazingly well.
And I'll tell you.... It was a L.O.T. easier fabricating it using the Honda cradle then it was building a cradle using pre-bent tubing.
And, we get a really strong Y section to boot.
The only drawback is scraping a 01 CR250 frame.
Then again, there is a lot of earlier CR250 frames on the market for cheap.
In fact, I found frames on eBay delivered for less money then the pre-bent tubes.
Time will tell if this was really a good way to go as we have a lot more of the build to go but it looks very promising.
Our goal is to build this bike as a weekend trail rider that can still go to the local MX track and give the 4 pokes a run for their money.
In the mean time I need to confirm using some of the earlier CR250 frames 97-99.
I will make a tracing on the wall of our cradle so doing the next one should be a lot quicker.
Stay tuned :-0

Posted: **Fri Jan 23, 2015 12:39 am**

My buddy Jason who is doing most of the work on this build.

: OEM-CYCLE.COM 2007 KX250AF BUILD 129.JPG (46.83 KiB) Viewed 9441 times

Old cradle.
Will save it for a rainy day

: OEM-CYCLE.COM 2007 KX250AF BUILD 130.JPG (32.61 KiB) Viewed 9441 times

Building a head stay

: OEM-CYCLE.COM 2007 KX250AF BUILD 131.JPG (54.09 KiB) Viewed 9441 times

Posted: **Fri Jan 23, 2015 7:40 pm**

So far everything is lining up great.

: OEM-CYCLE.COM 2007 KX250AF BUILD 132.JPG (87.45 KiB) Viewed 9433 times

Nice clearance on the gas tank.

: OEM-CYCLE.COM 2007 KX250AF BUILD 133.JPG (86.66 KiB) Viewed 9433 times

The tightest area is around the Y and the head stay.
Unfortunately in order to get the cylinder off you will need to remove the engine mounts and loosen the swing arm pivot pin, the tilt the engine back.
Not a big deal but it would have been nice not to have this issue...