Jump to content
Sign in to follow this  

Compression & rebound DRZ400 suspension


yeah I know a lot of you are just going to say look it up there are tons of threads about this already. BUT I already have and I have looked through a lot but don't really understand a lot of it, im looking for 2 things

1. a solid and simple explanation of rebound and spring rate all that

2. a recommendation of "cheep" fixes.. I called a local shop and I don't want to pay 600+ for them to change springs and revalve.

(not just being a cheap a$$) I am looking to upgrade to a new bike in the next year or two so im tired of dumping money into it.

im replacing my fork seals this weekend and I figured if I was going to have them open I minds well try messing with it

with all gear im about 230 and I ride street... if anybody has any clicker info or anything with shims stacks with similar weight would be great


1. Compression & rebound are pretty self-explanatory. Compression is when the suspension collapses/compresses and rebound is when it extends/rebounds. Most dirt/trail/enduro/mx bikes have adjustable (to a degree) suspensions. Generally the external adjustments include: low-speed compression (on forks & shocks), high-speed compression (usually only shocks), low-speed rebound (on forks & shocks) and spring preload (on forks & shocks). Internally damping is adjustable via shim stacks, bleed ports, pistons, etc…

Generally low-speed compression and rebound are adjusted with what are known as "clickers" (on the DRZ they look like flat-headed screws, with only the head visible). When you adjust them, you move a needle (right in image below) that sits within an orifice (left in image below).


Under low-speed movement of the suspension, some of the fluid inside moves through these orifices. By adjusting the clicker "IN" (generally clockwise) you partially close off that orifice. The more you adjust "IN" the more it closes the orifice. By closing the orifice, it takes more energy for the fluid to pass through because essentially you are making the orifice or hole smaller. So for compression it makes the suspension collapse slower (feels firmer) and for rebound it makes the suspension extend slower. The inverse is true when you adjust the clicker "OUT".

It's important to note, that the range of these clickers is limited. If you find yourself at the limits of their adjustment, then you need to revalve the suspension.

Spring rate, is a way to quantify a spring and it simply means the amount of force it takes to compress the spring x amount of inches. So a stock DRZ400S/SM rear spring is 5.5 kg/mm, meaning it takes 5.5 kg of force to compress the spring 1 mm. If the spring is linear, then it'll take an additional 5.5 kg to compress another mm and so on (11 kg for 2 mm, 16.5 kg for 3 mm, etc…).

2. At 230 lbs you need firmer springs both for the shock and forks. That'll run you around $200, no adjustment will compensate for springs that are way too soft for your weight. And no, adding more preload is not the answer… Then as far as re-valving, if you're a DIY kind of guy, you can make changes to improve the damping (I did myself). You will however need a few shims to make those changes as the stock valving is very soft.

Sign in to follow this  

User Feedback

Recommended Comments

There are no comments to display.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

  • Similar Content

    • By Big64N
      Good condition with a long list of high end upgrade parts.
      Rekluse EXP 3.0 with cover and slave
      EVO- Ellensburg suspension tuning for 6' 200# expert rider
      Fork bleeders
      Trail-tech map switch
      Moose 1-1/8 flex bar
      CYCRA probend bar guards
      SXS skid plate with linkage plate
      Clutch and water pump guards
      Frame guards
      Fastway Evolution III pegs
      SRT Pro Armor radiator and rear rotor guards
      Acerbic Front rotor guard
      TM designs chain guides
      DID race chain
      Renthal sprockets
      Gripper seat
      FMF F-bomb header
      Dirt Tricks timing chain tensioner
      Pro Wheel, wheels
      Tubliss front and rear
      New top end and valve adjustment 60 hours old
      Many more aftermarket parts as well as spare parts and service manuals included in the sale.  Willing to include 4 sets of tires with 80% tread left for full price.
      Great bike with plenty of life left and set up for anything from single track woods to wide open dessert.
      Can hang with any of the 450's but is much easier to handle in the tight woods.
      Priced to sell at $6000.00 
      Willing to consider reasonable offers but no trades or carry.
    • By filterx
      34 Days and what ever in Beautiful Chile
    • By TheBavarian
      Suzuki RMX250 two-stroke in excellent shape. Full bike overhaul 4.5 hrs ago. All work was done precisely to factory specs. Got receipts for everything.
      Rebuilt topend with new Wiseco Pro-Lite piston, rings, wristpin and wristpin bearing. Cometic gasket kit.
      New SKF wheel bearings and OEM seals front and rear
      Rebuilt Keihin PJ38 carburetor, jetted correctly
      New Twin air filter
      Silencer repacked with premier FMF packing
      Linkage fully serviced
      Swingarm bearings and bushing fully serviced
      Clutch, kickstarter and power valve serviced
      New OEM lower shock bearing
      front and rear brakes serviced
      Bike has:
      FMF Fatty pipe and FMF Turbinecore silencer
      Fly Racing Fat bars with Tusk bar risers
      oversized foot pegs
      Highline Recreation rear Tugger lift strap
      I also installed new Tusk D-Flex hand guards, Moose Racing pipe guard and Ricochet skid plate.
      Tires in great condition: Bridgestone M59 on the front, MotoZ Mountain Hybrid rear.
      Bike starts on first kick, idles and runs perfectly. 100% ready to ride.
      I was planning to build and keep this bike long term but now need to sell it.
      Also comes with full spare set of NSK wheel bearings, UNI air filter, owner's manual and other spare parts.
      Located in Seattle Lake City.
      Any questions, please text, call or email. (seven 34 - two 77 - 5742)
    • By Project57
      So if I can’t buy a used bike from out state looking for anyone that has or knows of a low mileage California 2017 / 2018 Beta 500 RRS?
      Thanks in advance!