Help on Front Fork Adjustments

I may sound like a novice, but I am bottoming on my front forks and need to make an adjustment.

How does one calculate the amount of oil, the weight of the oil and the number of outward clicks of the dampening screw(I think it is called a dampening screw).

The owners manual has some good stuff in it. If you don't have one, why don't you give more details like your weight, when it happens, is the bike setup still stock, etc.


You can also ask Jeremy at MX Tech. You can get his website and e-mail address from the tech section of this site. He's a great guy that knows everything about suspension setup and has offered to help us out when needed.


Sorry for not giving more details. The bike only has about 160 miles on it and everything is still stock. I just turned(clicked)the screw on top of the forks in almost all the way thinking that is all I needed to do. I am really not sure how the dynamics between the screw on top of the forks and the oil level and weight factor in together. The problem is, I am not at the bike right now. It's about 300 miles away. I am flying over there tomorrow to make some adjustments and ride this weekend. I am in Chicago and the bike is in southern Ohio.

If I'm not mistaken, it sounds like you turned your rebound all the way in, which is the screws on the top of the forks. If you are bottoming out, it would be the compression that you would want to harden up. Those are on the bottom of the forks.

I'm not a suspension specialist at all and I still am trying to understand the relation ship between rebound and compression. But I would set your rebound to the middle of your range. Then find the middle of your range on the compression (bottom of forks) and turn them in a few more clicks. Then you can adjust them until the point you are not bottoming. Trial and error on that part.


Dougie, '99 WR400

Mods: YZ timing, Race Tech Suspension, FMF PC IV, FMF Hi FLo Moto, YZ seat, IMS 3.3 tank, One Industries Graphics, Renthal bars, 14/52 gearing.

Here is a quick shot at the little bit that I know I hope it helps.

On the bottom of your front forks you will find a small black rubber insert. Pry it out with a small screwdriver. In there you will find your compression screw. If you want to help resist the bottoming effect turn the screw clockwise. This will increase the compression dampining force. Turned all the way in you should be at 20 clicks. From there you can turn it out a couple of clicks at a time to soften the forks until you get to the point where you are happy.

On the top of your forks which you already found is the rebound screw. By turning it clockwise you will increase the rebound dampening force. This screw turned all the way in is also at 20 clicks. I would go with Dougie's advice and set it about 1/2 way out and go from there.

Good luck and happy riding!!

Ya jlm400 has got it perfect. One additional bit of advise to add though about the rebound (which should be the last thing you set after the comp is dialed in). Only use as much rebound dampening as you need. If the front end springs back up way too quickly after being compressed then you need a little more rebound damening (clockwise). Only use enough to keep the front end from springing back up and no more than that, too little is better than too much. Same goes for the rear. Too much rebound keeps the suspension compressed and doesn't allow the wheel to track the ground.


'99 WR400

'92 GSXR 7/11

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You can also try raising the oil level height 5 mm at a time. The oil has a big impact on bottoming control. If you turn the compression clickers too far in (adding compresion) the bike will start to get harsh on the small stuff. I dont know what you weigh, but im 6'2, 200 and had to go heavier on springs front and rear, along with a revalve. that is the caddilac of suspension adjustments, but unfortunately it comes with a caddilac price. So the cheap way would be first trying oil height and clicker adjustments and then springs ( about 80 dollars.)

as far as rebound you know if its correct by the movement. as said above if you get sprung back up, rebound is too light, but on the other hand if it kicks side to side, especially in the rear, rebound is too slow.

I'm not an expert by any means, by I have had several bikes and have been through this process several times. I hope this info helps.

I have done just about all of the above. Im 6'6" and 230#. I eventually decided that stiffer fork springs were my only option. Luckily enough I have a buddy with a 99 YZ, si I just swapped fork springs with him.(hes about 170#) Its a bunch better than it was and I didnt have to spend a dime. :)


Darin from Missouri WR400F Pro-Tapers, Applied TC, Clarke 3.3, YZ seat, Scotts Shark Fin, FMF PC IV S.A., One Industries Hannah Retro Kit, WER Steering Dampner,Pacemaker Computer, Andrews Powder Coating-painted gloss black

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