What's a good fork height for XR400, and other questions.

[Eric T]

Hi all!

I have a '96 XR400, I'm 200 lbs, and I ride in the desert in western Texas - lots of sand. I have a bit of a headshake problem at high speeds (4th+ gear), which I usually reach when I'm riding down straight two-track trails (ie, from trucks, dune buggies, etc). The sand there is usually not very deep, but with lots of tracks. The front can really get wobbly on me, even if I'm not accelerating.

My forks are set level with the upper triple clamps...should I try lowering the front (raising the forks)?

What's a good level for fork height on my bike, riding mostly in deep sand? I'm at an "advanced-beginner" level...I've only been dirt riding for a few months, but I roadraced for a few years, so I'm picking things up pretty quickly.

 

[funnyloh]

hi there,
i am riding a xr4 too and also faced this problem.
heard that the 0.44kg springs will help.
but i am looking at a project which mounts an ktm LC400 USD fork onto my bike.
will let u know if it works.

Anthony

 

[shockdoc]

Eric T......first off at 200 # you need stiffer springs. This bike has a 10.0 rear spring & .38 forks springs. Very unbalanced. Usually if your head shake is at speed or while accelerating then yes, raiseing your forks a little will help. That or if your rear is sitting to low then you can help the headshake by raising IT up. Your headshake while just cruising or slowing down can happen from to soft in the frt. or stiff in the rear. With the stk. springs you may be able to adj. it to fix 1 prob. but will prolly cause a diff. prob.

Where is your sag? If you don't have aprrox 3/4 to 1" of free sag with 90-100 rider sag then you may need to get a stiffer spring. You will for sure need to go up to .44-.46 to stiffen the frt. then you will be able to raise your forks up a little in the clamps. Your bike will sit up at the top of the stroke better and handle the sand like you want it.


doc

 

[Eric T]

Thanks for the tips, Doc. Actually this is a used bike, and the previous owner was even heavier than me. I don't know exactly what spring rates are on the bike, but I'm fairly certain they are not stock.

In any case, I have a new set of forks coming, which will have 0.46 springs and Gold Valves. I have my race sag at about 3.75". I'm not sure about the free sag, I will have to check it. If it's less than .75"-1", then I will go ahead and order a stiffer spring.