Rear suspension adjustment - 2000 WR400F
Posted March 28, 2002 - 05:26 AM
Posted March 28, 2002 - 07:10 AM
Sounds like you are referring to the spring preload. I just use a screwdriver, but your wrench is better.
Loosen the top ring (lock ring). Set race sag by sitting on the bike in your normal riding position with most of your gear on (for weight). Have someone measure distance between the rear axle and a fixed point near the rear fender. Write the measurement down. Then put the bike on a stand with wheels off the ground and measure distance between same two points. The difference should be between, say, 3-3/4 inches and 4 inches. If not, loosen sub frame, swing it out of the way and adjust the preload on the spring until you have this difference in the two numbers. (You will have to keep replacing the sub-frame and slipping the top bolt in just to position it).
Take the bike off the stand, bounce it a few times while you are off the bike. Let it settle and take a new measurement between the same two points. The difference between this number and the longest number should be about 3/4 inch or 0.75". This is static sag. If this difference is much smaller (or suspension tops out), you have a spring that is too light. You are having to dial in too much preload in order to support your weight. Get a stiffer spring.
If you adjust this static sag to 3/4", and you then have less than 3-3/4" of race sag (while on the bike), then you have a spring rate that is too stiff (too high). Get a lighter spring.
Many riders adjust to suit riding style, but these are pretty good numbers to start with. You may also want to adjust damping, but write down your current settings before you start(number of clicks from full closed or full open on the adj screws). See manual for location of adjustment points and factory settings. Remember to tighten your lock ring and sub frame bolts.
PS: these particular models respond dramatically to a little time spent on setup. Your settings may change slightly from one type of terrain to another. For example: one day riding in rocks and tree roots, and one day on high-speed whooped-out trails or roads. Most of the bad press the WR/YZ has received for bad manners in tight, rocky riding has been due to poor suspension setting choices.
Posted March 28, 2002 - 08:59 AM
Posted March 28, 2002 - 09:39 AM
Posted March 28, 2002 - 10:27 PM
[ March 28, 2002: Message edited by: jbird ]
Posted March 28, 2002 - 02:03 PM
Posted March 28, 2002 - 03:22 PM
Hope you didn't spend too much on the wrench. Don't be afraid to adjust as long as you write things down.
Posted March 28, 2002 - 04:12 PM
Posted March 28, 2002 - 06:09 PM
The writing comes in when you are adjusting the damping, so you don't forget where you were previous to the new adjustments (so you can go back any time). Just keep track of how many "clicks" from full open or full closed. Grab a screwdriver and turn one of the adjusting screws 1/4 to 1/2 turn and then back. Feel the "click"? Just count those and keep track, and you'll be fine. Factory settings are in the manual in case you get it all screwed up. Can't lose. There's even a troubleshooting guide somewhere in the back of the manual that is only of limited assistance, but not too bad. Do it by feel and leave the adjustments where they feel best.
Rocks and roots will likely need less compression and more rebound damping. High speed, g-outs, and whoops will likely need a little more compression and a little less rebound. I usually use a compromise that's not too far from stock for all-around use.
Posted March 29, 2002 - 02:49 PM
This is all great advice given.
Just a note. Turning the spring even 1/8 turn produces quite a difference in sag. Small amounts can drastically affect handling.
Use a buddy to hold the bike up while you sit in a neutral position, and another bud to measure sag. Measure it a few different times over the course of a few riding days if possible, and measure with your full riding gear, including camelback.
Good luck and enjoy the bike!
Posted March 30, 2002 - 05:01 AM
Posted March 30, 2002 - 06:49 AM
Damping is simply metering a fluid (oil) through an adjustable orifice. The tighter the orifice, the slower the flow rate, the more resistance to movement. Most shocks today have individual adjustment for compression and rebound. The shock on the WR also has adjustment for high speed compression. HS comp adjustment is for the really big hits that happen suddenly. For example, you are doing 70 mph on a road, and you hit a rock or drop into a pothole. HS comp adjustment determines how the shock absorbs those kind of hits. Low speed compression adjustment is for whoops and rolling g-out kind of motion. The travel of the suspension is much less sudden, therefore the HS compression orifice is not a significant factor. The point at which one takes over for the other is a matter of personal preference, and subject to your adjustment. That's why you really have to be riding the bike to tell whether you like the settings. My settings may not be comfortable to you.
Pick a trail with obstacles that are typical to your kind of terrain. Start with factory default settings, adjust one screw at a time. If you want to experiment a little, you can go more than a click or two in one direction. That will likely emphasize the change in performance so it is easier to feel. You can always find a compromise setting that feels more comfortable. That way, you can see what effect each setting has on the handling. They give us these adjustments so we can dial everything in. If your XR had no adjustments, you'll be amazed at how much better this works when you take just a little time to set it up.
BTW, mcarp is right. A careful suspension setup (including spring preload) can make a dramatic difference.
Start with factory defaults. Experiment a little bit each time you go out, write down your settings (and maybe your results), and you'll begin to get a very clear picture of which settings seem to work best for you. Maybe you and I can't ride like Ty Davis, but we can have similar suspension performance.
PS: "high speed" compression refers to the speed that the suspension goes through its travel, not the ground speed of the bike and rider.
[ March 30, 2002: Message edited by: Dan from HB ]
Posted March 31, 2002 - 04:22 AM