Stiff suspension

7 replies to this topic
  • jaybird67k

Posted November 02, 2000 - 05:47 PM


Whats up guys ? Can I get my suspension more plush without spending high dollar on after market parts ? I am 165 lbs,........can I just back it off all the way on the soft side ? I hope you guy's can help back sure hurts alot, I'm taking a beating out there.
Thanks, Jaybird

  • Scott_F

Posted November 03, 2000 - 08:03 AM


I weigh the same as you, and yes there is hope. You will probably need a revalve for the feel you want. I can't give any further advice without all your details. In the mean time, it won't hurt to back out your adjusters.

Scott F

  • Guest_Guest_*

Posted November 04, 2000 - 07:58 AM


I backed mine all the way off and it helped alot but I have had to stiffen it up little since then, it will get softer as you ride it. I have read that it is not good for your suspension to do this but it didnt seem to hurt mine any. There is a shop in the Highlands that does suspension work, Ive heard he is real good and has fast turnaround.


  • DaveJ

Posted November 06, 2000 - 11:31 AM



There's been plenty talk of stiff forks via this board.

Here's how it works.

The compression on these forks is generated by a main compression valve, made up of what's called a two stage valve stack, (located at the bottom of the fork) and a mid valve, (which is located as part of the main piston assembly). Neither of which is detailed in the manual.

The two stage stack that I mentioned is made up of a low speed and a high speed stack. A "stack" is a stack of thin shims that are mounted up against a valve. The fork oil flows through the valve and attempts to deflect the stack of shims. The thickness and size of these shims is really what determines what the fork doesn when a bump is incountered.

The two stage stack is made up of two sets of shim stacks. One is called the low-speed-compression-stack, the other is called the high-speed-compression-stack. Speed refers to how fast the fork is moved based on the size and sharpness of the bump. Most of the stuff we do is low speed, (like whopps and jumps) but it it's the little stuff that is the problem, (fast hard bumps, large rocks, bumps on the down-hills...etc).

Lastly, the compression screw on the bottom of the fork is really a by-pass screw, since it controls how much oil will by-pass around the valve and valve stack. The more you turn it out, the less effect the stack has. In most cases, you want the valve stack to manage the majority of oil flow, since this is what offers the greatest ride quality.

In my opinion, turning the compression screw out all the way out makes the fork too springy, which results in less control. Obviously.

You'll feel this when you turn them out, hit the trail, then turn them back in and repeat the ride.

It's also my opinion that the factory stiffness that you feel is caused by the high speed valve stack, which can easily be remedied by removing some of the shims.

However, the combination of shims in a valve stack is a science all in itself. It's everything to a suspension. This is why the top shops get the bucks.

But you can also do like I do and simply experiment with different combinations until you get a feel with what you like and don't like. After a few attempts, it begins to make clear sense what works and what doesn't. And of course, you also quickly learn that what works for one track doesn’t necessarily work for another.

I can share what I'm running for my valve stacks and how to modify them, but you'll need some tools and patience to pull this off yourself.

Hope this helps.


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  • motoman393

Posted November 06, 2000 - 02:14 PM


I have heard the stock fork oil is junk? is this true? If so what should i replace it with (5w, 8w, 10w, etc)! I am 160lbs and ride motocross aggressively and jump big jumps at local tracks! Thanks for your help!


I get my kicks on a 2001' YZ426!
Friendswood, TX

  • jaybird67k

Posted November 06, 2000 - 05:00 PM


I sure appreciate all the help and I have since then got it working to my advantage, so my suspension is slowly coming around, now If I could just ride like the pro's iwould be at peace...........Thanks again.


  • YZThumpa

Posted November 06, 2000 - 05:09 PM


Jaybird, I am very inexperienced (2000 YZ 426 is my first real bike) and just about everything posted on this site is way over my head. I tried turning out a few clicks but can't really tell the difference. However, from a couple guys I talked to at the track and from some postings on this site it seems like adjusting the sag and leaving the high tech stuff alone should make a significant difference. At least I hope so. I still don't know how to adjust the chain or change the oil much less fool with shims in the forks. But someone at the track who always fares well told me he set the sag at about 4.0 inches and left the rest alone and it feels very plush. Once I figure out how, I will do the same. P.S. This site is a Godsend. At least I'm learning the "language" so I know what I need to learn!

  • jaybird67k

Posted November 07, 2000 - 03:29 PM

#8 got some good info !
I also set my sag at 4 inches and acheived great results. I was told by Thumper Racing to set the clickers at the stock setting and set the sag to 4 inches for my weight (165) and then if you have to add some rebound to help on the little bumps at high speed. You need to change that oil as soon as you can, I have about 5 hours on my bike I have made 3 oil changes. Later.........

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