KDXRIDER.NET

The bike looks good with all that mud.

This comes up frequently, but you need to route that front brake line on the inside of the fork so it doesn't get caught.

I tried mounting the brake line on the inside but it has a natural bend in it that causes it to hit the spokes of the wheel. Those are the KDX front brakes, for now we are just going to have to take the risk with it being on the outside. That same natural bend has the line firmly pressed up against the fork leg so it's not just flopping around but I know there is still a high risk of something catching it the way it is now.

Mine was just the opposite, the natural bend pulls the line out against the guard. easy enough to clamp it there, and is really worth the effort compared to the cost and time to replace a snagged line, along with whatever else breaks as your homegrown version of a navy arresting hook introduces you to the ground

So the frame was not jigged solid when you cut it?

I am surprised you had no issues.
Might be good to watch for cracks.

hybridracing65 wrote:So the frame was not jigged solid when you cut it?

I am surprised you had no issues.
Might be good to watch for cracks.

Of course we are going to keep an eye on it but why do you think ill have issues with it?

I think he might be referring to torsional rigidity, you see it with stressed frame members where the frame is under tension in its final shape. In such a case, when you cut the frame it tends to spring back to its original shape. Then when you weld the new part in the rest of the previously stressed joints are now in a different position which can lead to stress cracks. As far as I know these older steel frames weren't designed or built that way. Or I could be way off base.

bufftester wrote:I think he might be referring to torsional rigidity, you see it with stressed frame members where the frame is under tension in its final shape. In such a case, when you cut the frame it tends to spring back to its original shape. Then when you weld the new part in the rest of the previously stressed joints are now in a different position which can lead to stress cracks. As far as I know these older steel frames weren't designed or built that way. Or I could be way off base.

Same thing I think that he is trying to say. But all I have to say about that is oh well its to late now, the bike is done. I will keep and eye on it but i didn't know that it could be an issue till now. Iv looked at just about every other hybrid thread on the internet and this issue never came up.

sorry been away.

Yes once a steel frame is welded and it cools it is usually in tension. Not sure about the steal box frames but i know the older normal single tube split Y frames are this way. Best to jig a steel frame before you cut it. You will see the frame unload when you make the cuts.
This can also effect geometry for handling.
You will not find this reading up on AL frames and most steel hybrids do not require changing the cradle completely, just the mounts which is why you probably did not find anything.

Just suggesting you keep an eye on it, thats all.

yes we will keep and eye on it. Hopefully at the end of the season it will get stripped down and rebuilt with powder coat and all. It will get checked good then. It handled better than expected. I loved it, it took nothing for me to hop in it and pound some laps since I'm used to the handling of MX bikes. He is still trying to get used to it since all he has rode is a kdx but i can already tell that he is quicker on it.

okay i want to do this after seeing it. what did you use for tubing?

I'm doing the same hybrid right now. Can you tell me the grade and size of tubing your used?

The OP hasnt been on here since August 2013. Maybe you will get lucky and he is still getting email notifications.

Yeah I saw that right after I posted oh well. Hopefully...

old thread but i think info is relevant so here goes

i would use DOM / hydraulic / seamless tube to make the frame down tubes

I actually got some one at Kawasaki to tell me the type and size of steel they used but thanks. She's been running hard since March!

What were the details on the steel?

Thanks.

It's 4130 hi tensile steel 1"od 1/16" wall thickness It's really tough to bend!

Hello i am doing a simular project, 2006 RMZ250 frame and 97 RMX250 engine. However the right radiator interferes with the exhaust. Did you use the radiators of the kdx or the original rmz ones. thanks. Ps the rest is done, carb fits the airbox sprockets line up, exhaust is finished.
The only problem is right radiator and the hoses. I am thinking of buying silicone hoses and bend them myself. Any advice is welcome.