my poor bike

[jBernard]

d**n that would have been nice to know 

[LundMx]

it makes me want to gusset mine now to make sure it does not happen to me! 

[sandblaster]

It makes me think that we need to prevent the engine from rotating counter clockwise using the pivot pin as the rotation center.
Any word on if the Service bikes are having this problem?
If not, what are they doing different?

[don46]

I looked at the pictures again, and I think both were showing signs of failure, one not nearly as bad as the other. Like I said before, this is a 250, maybe there are different harmonics involved than you'd see with a 500. I recently looked at the AL framed 250 I built, didn't see any signs of immenent failure, although I'm sure the original poster felt the same.

[brooksie]

This is very worrying. It's seems I've just built a very expensive garage ornament! I'm getting rather afraid of using the thing now. Are the frame rails JFab supplies radiused or square?

Talking of JFab, he makes a superb head steady. I think it would be far easier to have a similar bracket made for the front which picks up on the cylinder head studs. Then just a boss welded to the down tube and job done.
No guarantee, but surely a help.

Just another thought. The rails I removed from my frame were square. No radius whatsoever. Obviously Kawasaki thought the square tube was up to the job. Therefore it's something that is being introduced during the conversion. My suspicion is the lack of heat treating. There's a few frames that have let go now in more or less the same place which appear to be due to fatigue. Until somebody can supply a definitive material/heat treatment process, failures are going to continue.

[sandblaster]

Talking of JFab, he makes a superb head steady. I think it would be far easier to have a similar bracket made for the front which picks up on the cylinder head studs. Then just a boss welded to the down tube and job done.
No guarantee, but surely a help.

Like this?

[brooksie]

Bingo! What would make it a little nicer would be to have the steel compress against the aluminium. Then only an aluminium boss would need to be welded to the frame instead of that bracket. Less chance of fatigue as well. It would make it "less busy" in that area and aid getting the motor in and out prividing a little more room.
As it is, I don`t see enought clearance to get the head on if the bracket was welded to the frame as it is.
In any case, I`m going to have to do something like this before I ride mine. I`m just not going to have any piece of mind otherwise. The originator of this thread was extremely lucky to come away with just a scratch and a bruise. He must bounce well!

[sandblaster]

There is room to remove the head.
I'll demonstrate when I'm a bit further along.

[brooksie]

Personally, Id still prefer the steel squeezing the ali. Do you have a computer file for the plate...
What material have you used...

[sandblaster]

I designed one just in case they were no longer available.
But, they are still for sale:
http://www.kxriders.com/forums/index.php/topic,6447.0.html

[DSPMOTO]

@motopunk  the frame rails that we made were thicker than the oem frame rails. i beleive it was 6061 that was used.
i am waiting to hear back from the guy who did all my welding/cutting/bending to  get all the correct anwser for these questions.

@motorrad  what kind of tubing should i have used? the oem frame rails were square so i went went the square just a little bit thicker.

@jBernard  the head bracket broke in the crash from the force of the bike hitting the ground. i would have noticed if it was broke prior to the frame breaking. i think i would of had more than normal vibration going on. i can pick up on very small details to my bike with riding. i have done a lot of testing in my professional career as a racer. i aslo pay a lot of attention to my bike everytime i service it which is everytime i ride.

@don46 from the pics it does look like both rails were stressed. when i check the bike out the day after the crash the rails did not have all the black resude on the breaks. i could be wrong but that is from moveing it around on the floor of the garage. the left rail deffently broke frist thought. you can see in one of the pics that the right rail was twisting when the frame did break. to me that would mean that the left gave out first and the right side was holding on for dear life. when the guy who did all the welding and stuff came to look at the bike he didnt think that there was and pre failure prior to the break. idk, we will never know which is the worse part about it all.

@sandblaster i am not sure if the frame was heat treated or not.  again waiting ot ask the welder bc i dont i dont want to answer that question wrong. im sure i will talk to him over the weekend and find all this info. please feel free to ask any other questions so i can ask him (that goes for everybody). i do like your extra head stay mount. but wouldnt that make the frame more rigid? jw wondering for when i build a new one. def going to take everybodys thoughts into consideration.

@brooksie i do bounce well, over the course of my racing career i have learned to tuck and roll. lol the only thing that happen to me in the crash was ofcousre i got knocked out, but on the way over the bar the left side of the frame caught my boot. sliced about a 3 inch slot in the side of it. hit me in the leg which gave me a really big bruse and also broke  my CTI2 in half. if i didnt have that brace on my left leg would have been shattered. i do know that i was very very very lucky to be able to walk away from the crash!!


ps for everybody please dont take any of these responces the wrong way. i but my bike on here for a reason. to show everybody what happen and to help everybody out with there builds. i do not want to see that happen to anybody else and i dont think i would be able to walk away from a nother frame breaking. so lets put are heads togther so we can mack these bike bullet proof.  bc these bike are just dont right awesome!!!!!

[don46]

OK, so the stock bike does use a radiused tubing, I have a picture also a couple of side by side pictures of radiused versus non, they do look suttle but there is a difference

[sandblaster]

@sandblaster i am not sure if the frame was heat treated or not.  again waiting ot ask the welder bc i dont i dont want to answer that question wrong. im sure i will talk to him over the weekend and find all this info. please feel free to ask any other questions so i can ask him (that goes for everybody). i do like your extra head stay mount. but wouldnt that make the frame more rigid? jw wondering for when i build a new one. def going to take everybodys thoughts into consideration.

ps for everybody please dont take any of these responces the wrong way. i but my bike on here for a reason. to show everybody what happen and to help everybody out with there builds. i do not want to see that happen to anybody else and i dont think i would be able to walk away from a nother frame breaking. so lets put are heads togther so we can mack these bike bullet proof.  bc these bike are just dont right awesome!!!!!

It's hard to say if that will make the frame more rigid or not.
I don't believe so.
I guess I will have to let you know after mine has been torture tested 

I am very glad you posted your problem and I certainly don't take anything you have said as negative.
We are all trying to help one another so anything that can add a positive light, I'm up for it and I'm sure most others feel the same way as well.

Thanks!

[The Flyin Hawaiian]

@brooksie i do bounce well, over the course of my racing career i have learned to tuck and roll. lol the only thing that happen to me in the crash was ofcousre i got knocked out, but on the way over the bar the left side of the frame caught my boot. sliced about a 3 inch slot in the side of it. hit me in the leg which gave me a really big bruse and also broke  my CTI2 in half. if i didnt have that brace on my left leg would have been shattered. i do know that i was very very very lucky to be able to walk away from the crash!!

The CTI2 has a lifetime warranty. I destroyed mine, shattered the top part and broke it in half and it was repaired free of charge. Glad your ok!

[brooksie]

I just got a new set of custom CTI's. Great kit.

Well Don46, good info. But you've pissed me off no end!
What type does JFab supply, anybody know?
My frame rails are as square as can be. I really don't know what to do with this bike now. The more I read, the more concerned I'm becoming about using it. While I'm no top flight Pro, I'm still pretty quick but don't want to have an avoidable accident. I DON"T bounce well!