Rear Suspension Question

5 replies to this topic
  • bobpara

Posted July 27, 2015 - 10:51 AM


I have an '06 WR450 that I bought used a few years ago. I assume all of the suspension is stock.


I use the bike for a mixture of trail riding single track, powerlines (wide open) and light-duty motocross. I run into lots of whoops in the trails I ride so an MX-ish setup would be good


99% of the time a Japanese bike comes from the factory with a set of springs (front and rear) that are too soft for your average rider.


My bike seems too stiff. To get the right amount of sag I have to loosen the spanner nut at the base of the spring to a point where the spring is not even held in place by the spanner nut anymore and can rattle and I think the spring is too stiff if I cannot get the right sag.....correct?


Secondly, what do you guys use for compression & rebound dampening settings? Right now I have them all at the mid-point

  • RockerYZWR

Posted July 27, 2015 - 12:29 PM


How much do you weigh and how are you measuring (what procedure are you using to set) your sag?


Suspension settings are going to be different based on your particular conditions, preferences, riding style, bike (suspension) condition, and body weight.  Asking someone else what they use is really sort of futile.  Generally, sand track/dunes - stiffer compression, faster rebound; woods/rocks/logs/ruts/other - somewhere closer to the middle on both with enough compression to barely bottom on anything but maybe the worst g-outs or flat landings and still have a good plush feel in the small stuff, and enough rebound to control the side-side kicking when it gets rough without feeling either too dead (packing) or too springy.  Bottom line is it takes trial and error to get it right, which takes time and discipline (and a flathead screw driver); go ride, change settings (only one thing at a time, and only 2-3 clicks at a time), go ride, change settings, go ride, etc, until you notice the bike working better for you.  Write it all down as you go.  Avoid the temptation to give up and just go ride that day - treat it like a job.  Once you get your settings for that bike, you've got them.  I have specific woods and sand settings (that I spent hours finding) that I set the night before a ride so it's all set up before I even get to where I'm going.  Then I tweak from there based on how things are going that particular day.  It also took trial and error to find my best SSS fork outer chamber oil volume for me on each of my bikes (especially since the YZ is about 45 lbs lighter than my WR).  Spring rates should be fairly straight forward based on the bike's and your weight and your riding ability - but getting those right is step one in the process.

  • RockerYZWR

Posted July 27, 2015 - 12:42 PM


Referencing your other thread about front suspension.  For the '06 WR open bath forks, you'll measure oil height with the whole spring assembly (spring, damper rod assembly, and cap) out.  When I was using those forks and had installed some Race Tech gold valves, RT recommended 120mm for me - I ended up around 105mm oil height after trial/error to help control bottoming and stroke without dialing in excessive compression.  To measure, I use a small metal millimeter scale that I carefully dip into the open, compressed fork (don't drop it in there), with "zero" at the top and held flush with the top of the fork tube.  Then remove it and look to see where your oil line is, just like a dip stick.  Distance from the top of the tube is what you're after.

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • Krannie McKranface

Posted July 27, 2015 - 01:31 PM


If the forks/shock, still have the original oil in them, it needs to be changed

Your springs are too stiff if you are trying to set the sag correctly and get spring flopping

Your adjusters are +/- 15% of the base valve's valving.

  • bobpara

Posted July 28, 2015 - 06:35 AM


I weigh 205 lbs w/o riding clothes

I first have to get the springs right

Stock front according to manual should be 0.450 kg/mm (not 100% sure of the units)

Stock rear is supposed to be 5.3 kg/mm (again not sure of units)

  • bobpara

Posted July 28, 2015 - 06:38 AM


I also ride in a wide variety of conditions, which would effect alot of valving, compression damping, rebound, etc

But as far a spring rate goes, I think that is purely a function of rider weight pretty much, unless i am looking for a supercross setup

I do riding down in the cape (Cape Cod, MA) which is wide open sandy Baja like riding. Lots of whoops too, basically a sandy track MX setup

Then I head 50 miles north and is all loamy, rocky, roots, wet cow-dirt single track


A wide variety


Join Our Community!

Even if you don't want to post, registered members get access to tools that make finding & following the good stuff easier.

If you enjoyed reading about "" here in the ThumperTalk archive, you'll LOVE our community. Come join ThumperTalk today!

The views and opinions expressed on this page are strictly those of the author, and have not been reviewed or approved by ThumperTalk.