Steering shakes at high speed

Technical stuff specific to the Raptor 650
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Dante
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Re: Steering shakes at high speed

Post by Dante »

I dont think that any of the previous owners has changed anything at the fork.
Do you have handy any link on how to adjust the sag for the fork and the rear suspension?to get it done once I change the triangles.
Thanks for the help!

What are the yokes?a picture would help :blush:
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Crap Tartan
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Re: Steering shakes at high speed

Post by Crap Tartan »

I cant really give you details on your forks as cant check against mine as I have Yam R1 forks fitted.

Yokes are the triple trees that hold both fork legs on connect to the frame through the steering head.

The fork legs can usually be slid through the yokes by loosening all the clamping bolts. Small adjustments here can have quite a large effect. You would have to get someone with a standard 650 on here to measure theres to see if yours are set in standard position as I am not sure if it is in manual.

A guide to setting sag is here

http://www.visordown.com/workshop/adjus ... 15899.html

Google is good for more info.

You will need a help to do dynamic sag (or rider sag) as you need to be sitting on bike with it held upright so get you mates round! The standard suspension doesnt have much adjustment so you cant do a lot with it but at least it gives you a known start point by setting your sags up.
nil illigitimae carborundum
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Dante
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Re: Steering shakes at high speed

Post by Dante »

I gave the dimensions to a friend of mine.

Image

this is that I'll make.propably from stainless steel.may be overkill but doesn't harm to have a better material.
As I don't want to jack it up a lot I'll reduce it by just 4mm and not 5mm.so the tail will come up I guess by 2cm.
roadrunner
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Re: Steering shakes at high speed

Post by roadrunner »

done 200k+down the straight at Philip island on my 650 only thing that flapped was my leathers need plenty of pressure on the bars but run straight. sounds like bike lifting a bit from your body resistance to wind drag.if anything serious would do it at slightly lower speeds.
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Dante
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Re: Steering shakes at high speed

Post by Dante »

Measured the SAG
At the rear its ok.
At the front the preload is a bit high.
I have 28 and it should be 40.
At the rear it should be 43,3 and I have 45.
What can be done at the front?Could this cause the shake?
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Dante
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Re: Steering shakes at high speed

Post by Dante »

Remeasured it after studying a bit.
I think I did it right this time.
At the front 32 and at the rear 43.
Also I wasnt wearing any equipment and the tank was half full so I guess this would be a bit higher.
So I guess the preload at the front is ok and at the rear needs a bit stiffening...
shedmonkey
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Re: Steering shakes at high speed

Post by shedmonkey »

there is some discussion on here about the air gap in the forks, which means the volume of oil to air ratio which makes the air volume behave like a spring, you could try loosening the fork top caps in case they have pumped up and are storing a little pressure. The other question is has anyone already played with the forks? Personally i think the figures you have probably would not cause your shake.
Bit of a Muppet
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