head shake

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terminatr
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head shake

Post by terminatr »

Hi. Just got my new '01 KDX-220 legalized for street use. So I took the bike onto the highway for the first time. At around 45 MPH, the bike started to head shake like crazy. I was afraid to go much faster because it was so bad, and I wasn't wearing any safety gear. THe front of the bike was bouncing up and down, but the road was really smooth. My Honda XR-200 can do 60 MPH without any headshake. What is causing head shake on my KDX? My suspension is stock except I replaced the rear spring with one recommended for my weight by Fredette (I weight 150).

Race sag: 3 inches (without wearing any gear)
Static sag: 1 inch

I haven't check the balance of the tires.
2001 KDX220
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Julien D
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Re: head shake

Post by Julien D »

I've done 70 on my 89 and wasn't a bit scared. Assuming your bearings are good and all is lined up correctly (first thing to check), you may think about removing the front rim lock or adding a second to counterbalance the existing one.
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terminatr
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head shake

Post by terminatr »

Yes, the front wheel bearings are new. Steering head bearings feel good.
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SS109
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head shake

Post by SS109 »

Tire balance is one thing to look at. Also, some off road tires just don't like high speeds on pavement no matter what. You said you have the correct rear spring. What springs do you have in the front? Also, are the forks flush with the top of the triple clamp or are they above it and by how much?
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diymirage
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Re: head shake

Post by diymirage »

ive had my 96 up to about 75 on the highway and though the confort level drops damatically at 55 my concern is more with the engine howling then anything else

and that is with a rather smooth knobbie AND rimlock
newbbewb wrote:DIYmirage has it right.


-1996 KDX 200 woods weapon (converted to 99 green body)
-1996 KDX 200 plated street toy (barney edition)
-2003 Yamaha TTR125-L (wifeys bike)
-1997 KDX 220 project bike
terminatr
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head shake

Post by terminatr »

SS109 wrote:What springs do you have in the front? Also, are the forks flush with the top of the triple clamp or are they above it and by how much?
As far as I can tell, everything on the bike was stock when I bought it. So, I'm pretty sure the fork springs are stock. Yes, the forks are flush with the top of the triple clamp. There's no lowering link either. So, suspension is at stock height. Front tire is Dunlop Sport K490. I will buy a tire balancer tomorrow.
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head shake

Post by SS109 »

terminatr wrote:As far as I can tell, everything on the bike was stock when I bought it. So, I'm pretty sure the fork springs are stock.
So that begs the question, how much do you weigh? The stock fork springs are only good for a 130-135 pound rider.
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terminatr
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head shake

Post by terminatr »

150 pounds
2001 KDX220
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