steel frame head mounts

[Goat]

That's pretty fancy work MP. Hows the vibes on that bike with that style headstay?

[motopunk]

That's pretty fancy work MP. Hows the vibes on that bike with that style headstay?

thanks...   

vibrations are less than i thought before. by the rebuild of the engine i installed a new conrod kit and the crank is now well balanced. thats also a big factor for vibrations. my engine runs like a swiss clock . before the engine rebuild the bike vibrated so much, that it fell of the stand by idling. after rebuild it stays and feels better by riding on the mx-track.

the brackets from headstay to the frame are made of aluminium. that sucks also a little bit of the vibrations , that the engine would give to the frame ..

[kranker1450]

2000 Kx250

Is the mount going to be welded onto the frame or bolted?
I'd love to weld it but not any decent flat steel to weld to because of where the 250 motor mounts land.

It is suppose to mount to the frame using the stock mounts. i have not had any time to look at it so i am not sure how it will go. i would expect a little fiddling since everyone of these conversion will be a little different since we are all doing our own fabrication. lol

[motopunk]

2000 Kx250

Is the mount going to be welded onto the frame or bolted?
I'd love to weld it but not any decent flat steel to weld to because of where the 250 motor mounts land.

It is suppose to mount to the frame using the stock mounts. i have not had any time to look at it so i am not sure how it will go. i would expect a little fiddling since everyone of these conversion will be a little different since we are all doing our own fabrication. lol

question: why making new mounts to the frame, when all is there, what you can use easily? 

[yeomans]

I was planning on using steel for my mounts, But I understand what your saying about the aluminum dampening some of the vibrations.
I don't have any gear for welding aluminum, so I might have to go see my machinist.

[motopunk]

only the brackets(plates between headstay and frame) are aluminium. the headstay itself is steel (painted it silver against rust).

[Goat]

only the brackets(plates between headstay and frame) are aluminium. the headstay itself is steel (painted it silver against rust).

I thought the whole thing was aluminum. Fooled us with the fancy paint job

Now you have me thinking I need to send my crank to someone. My 87 vibrates pretty bad. Only use my stand to work on the bike. If I start it I stay on it but I would guess it would vibrate off the stand.

I am in the same situation yeomans. No aluminum welding for me so everything gets made of steel. I always overbuild everything too, as in 1/4" plate instead of 1/8". Sometimes that does more damage though.

[motopunk]

only the brackets(plates between headstay and frame) are aluminium. the headstay itself is steel (painted it silver against rust).

I thought the whole thing was aluminum. Fooled us with the fancy paint job

Now you have me thinking I need to send my crank to someone. My 87 vibrates pretty bad. Only use my stand to work on the bike. If I start it I stay on it but I would guess it would vibrate off the stand.

I am in the same situation yeomans. No aluminum welding for me so everything gets made of steel. I always overbuild everything too, as in 1/4" plate instead of 1/8". Sometimes that does more damage though.

  .. thought your eagle eyes had seen the material diference...

[yeomans]

Vibration is my main concern, I've seen some nasty breaks at the head studs before in a friends go kart.
I am getting the crank rebuilt and balanced for the build, hoping this alleviates some vibration right at the source.
I had made a mock up mount out of steel, but I'm now wondering if aluminum might be the best material, I'm sure theres a reason the Japanese use it for the headstays.
It's funny you mention overbuilding, Starting to think about what extra welds the frame would benefit from before it goes to powder coat.  

[motopunk]

"I'm now wondering if aluminum might be the best material, I'm sure theres a reason the Japanese use it for the headstays."

the same thoughts that i also had. reasons for aluminium-brackets are 1/3 less weight than steel and another arrangement of the atoms in the material, which helps to eliminate some of the vibrations on the direct way from motor to the frame. 

and an important fact: a bad balanced crank makes the whole bike shaking like a rodeo-bull .

[cmotodad]

I saw some steel head stays on a factory Kawi a few years back. I think it was when RV was struggling with the pre 2012 450. I made some and put them on my 10 450 and could feel the difference. I liked them more than the stock alu. ones.

[yeomans]

Liked them because of less vibration ?

[cmotodad]

I think the thinner steel head stays allowed the stiffer 9-11 frame to flex a bit more. I did not notice any vib difference. I was at a SX at the time and saw how a couple of the factory bikes had thicker, thinner, al. and steel stays. That was my reasoning.

[motopunk]

hmmm.. please dont make the mistake to compare a 450 4stroke in a stiff al-frame with an 500 2stroke engine in an flexible steel-frame ... thats like comparing apples with potatoes.. 
4strokes make diferent vibrations than 2strokes .. al-frames are always stiffer than steel-frames because aluminium weighs 1/3 less than steel, but for the same durability it needs 3x bigger dimensions as a steel-frame and that makes it stiff and less flexible than any steel-frame..

[cmotodad]

Flex is flex no matter what type motor is in it. Steel flexes more than alu. frame. If the head stay indeed allows more flex, it should not matter.JMO