Headshake on 01 RM 80

[KDXDan]

My 11 year old son crashed hard Sunday on his 01 RM80 winding the bike out on an old asphalt road. He is banged up pretty good with a shattered clavical and lots of road rash. Him and a witness stated that his bike had headshake at high speed and he did his best to control it. I know (and he does now) that he should have not been on asphalt (thank God for proper gear). My question is has anyone else ever experienced headshake on a RM80? The suspension was set up by PR2 and the guy we just bought the bike from raised the tubes a couple of mm's due to my sons being smaller than his. Can I eliminate the headshake by lowering the fork tubes? Thanks.

 

[MikeS]

I have of this alot. But my guy never had it but I have seen kids on the same bike on the same track crash from it.

First check the steering head bearings. Grease them and set them a tad snug. Raising the tubes can make bike unstable at speed. Put them back to stock.

Consult the tuner. Not knowing the spring rate or your sons weight or ability, it is tough to judge things. On pavement if you got that thing shaking then it could be the steering head bearings but a rippled road surface can cause havoc.

Good luck ... if stuck give some more detail on the fork set up and rider details.

 

[KDXDan]

Thanks MikeS,
I'll check the torque of the steering head. Fortunatly the previous owner has a grease fitting in the head tube.

 

[dell30rb]

You definately need to lower the tubes. This will help out a bunch.

Remember to torque the clamps properly

 

[KDXDan]

"Remember to torque the clamps properly"
1. Tighten top clamp first.
2. Grab front brake and rock the bike to compress forks.
3. Tighten bottom clamp
Is this correct? I don't have the book in front of me.

 

[MikeS]

The RM with conventionals are not as critical but you can do it as mentioned.

 

[ktmdad]

We had the same issues on out '00 RM 80. Tightening the steering stem bearings and extending the forks in the triple clamp helped out. But also get the front suspension dialed in for you rider's weight. This will really help to cut down on the headshake.

 

[ACS]

OUCH!!!! Hope he is going to be ok. Forks maybe too firm for his weight and too far up in the clamps. My boy had this problem when he went to the YZ125. Setting it up properly for his weight (lighter springs and damping mods) and gripping the bike with the knees solved the problem. Many juniors have the problem most have difficulity describing it and then us parents have to sort it out. The gripping it VIP.