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Head Shake - 03 CRF450


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I have about 20+ hours on a '03 CRF450F. I sold the YZ250F and couldn't be happier except for one problem. I have the suspension dialed in perfect except for severe head shake on braking and acceleration bumps. It is worse on braking bumps. The bike is stock except for a 52 tooth rear sprocket and Pro Taper bars.

Anyone else experience this and find a cure?

The only other complaint is the clutch lever rattles to no end!

Thanks in advance.

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If your getting headshake, your suspension isnt as dialed as you say. It sounds too soft to me.

I got some headshake out of my YZ when it was too soft. I havent had any headshake out of my CRF at all.

Id go a little stiffer with the compression clicker in the fork.

I just re-read your post. It says yovue got 20+ hours on the bike, did you ever change the stock fork fluid?? If not, its definitley time. And if you did, its time again!!

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What free and race sag are you running and how much do you weigh? If you run too little race sag (rear too high) it steepens up the steering which can cause head shake. If you are a heavy rider and you set the rear sag by using preload only (instead of using stiffer springs front and rear), the front sag will be too excessive (front too low) and that can cause head shake too.

The 04 CRF manual calls for 100mm of race sag with the rider in full gear and 15-25mm of free sag (no rider).

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Thanks for the ideas. I have tightened about ever nut and bolt EXCEPT for the steering stem nut. I will check it tonight.

To answer some other posts.....I have not changed the fork oil...I weigh 185...race sag is 95mm....free sag is 30mm...

The suspension works so well everywhere else. Whoops, jumps, cornering is all sweet. As far as speed, this bike rarely sees 4th gear and has NEVER seen 5th.

Thanks.

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Here's a setup sheet I got when I had my 96 CR suspension done by C-Cycle a while ago.

Fork syptoms:

* Fork bottoms then try comp in 2

* If too harsh then try comp out 2

* Packs on 2nd and 3rd bump then reb out 2

* Bounces up after jumps then try rebound in 2

* Arm pump or head shake then out 2 rebound

Shock symptoms:

* Shock bottoms then in 2 on comp or 1/4 turn HSC

* If kick side to side out 2 on Comp or 1/4 turn HSC

* Packs on 2nd & 3rd bump then reb out 2

* Kicks straight up then try reb in 2

* Poor traction then out 2 on comp

Muddy conditions - increase comp fork & shock 1-2 clicks

Below 40 degrees F decrease fork rebound 2 clicks out

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crf has five gears?? where the heck do you use 5th, anyway i went from a yz250f to a crf450 cause i blew my motor on the 250. i have been riding two weeks. i dont like the cr yet. i got my yz back today and cut 7 seconds off a 4 lap moto with it over the cr. my cr has head shake to no end. i dont care what suspesion setup it doesnt go away at high speeds on bumpy ground. i have a scotts dampener on the yz and it is awsome. i have tried everything on suspesion setups to get rid of it and no luck. tightening your stering stem will give you arm pump if you tighten it enough to work. anyway at least the crf is faster.

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Contrary to popular belief, a damper is not intended to "CURE" headshake! If your bike headshakes that bad you have other problems, as others have stated. The damper is only there to help out with the occassional extreme instance. Look for your problem...suspension, steering head bearings...etc. The damper is not a bandaid fix. TW

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To answer some other posts.....I have not changed the fork oil...I weigh 185...race sag is 95mm....free sag is 30mm...

Have your forks serviced (and your shock too while you're at it).

Check your sag again.

Try running a few clicks more high speed compression on the shock (do this independent of changing the sag).

When the front end gets upset, lean forward, not back. Read your number plate upside down.

Hope this helps, but if the 250 handles anything like the 426 I'd agree the Honda is more busy up front. It could be as much rider perception as anything...

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Before anything else, make sure fork comp and rebound adjusters are matching, leg to leg. This bike has very subdued geo'try (as far as race bikes go)something is amiss. I have my legs pulled up 8mm and have run as little as 90mm of sag with that height, no shake...

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Thanks to all for the ideas. I found both the steering stem and top fork pinch bolts at 1/2 the recommended torque settings. No Headshake at all yesterday although the track was a bit muddy so speeds were down. I am hoping the problem is gone for good...

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