What is what?

[MattR]

Krasi,

Those are decent links. The guidelines from Bruce's Suspension and MX-Tech are similar. Here is the MX-Tech guideline:
http://mx-tech.com/downloads/tuning_guide.pdf

Like iancp5 mentions, it is very important to first get your sag settings correct. If your race and free sag settings are in the ballpark, then you have the correct spring rate and preload. If these are not right, then you will be fighting balancing issues (front to back) along with damping issues, so it is best to eliminate some variables.

Assuming you have the spring tuned properly, then I agree with Bruce's and MX-Tech guidelines to start with rebound damping. It provides the most control and most folks mis-diagnose issues and play with the compression adjusters. If you get the rebound set right, then you won't be changing this later on too much.

The final step would be adjusting the compression adjusters. You can soften this up until you find yourself using too much suspension travel. Then, slowly add more compression damping.

Sequence:

• Ensure all suspension linkage, pivots, etc. are properly greased and smoothly working.
• Springs (preload and rate) adjustment
• Rebound adjustment
• Compression adjustment

For your specific example, I would add more rebound damping control (stiffen it up). Your compression may be fine, but it may help to reduce it slightly.

[MattR]

It may also help you to put a plastic zip-tie around the lower fork tube. Put it on lightly and position it against the dirt wiper. This will provide a quick check on how much travel you are using.

[Skidad]

Krasi,

How much do you weigh? Most new bikes are set up from the manufacturer for about a 175 lb rider (79.4Kg). If you're considerably outside this range either lighter or heavier you will most likely need different springs and this would need to be addressed first or everything else is out the window.

Search the suspension forum for setting the rear sag especially and don't be afraid to turn away on the clickers to see how changes affect the bike.

One of the best things you can do is find a nice short loop that is typical of the riding you do. Spend the day riding around that same loop and just keep trying different adjustments and rear sag settings to see how the bike reacts and what feels best. Go from one extreme to the other to feel the affects of the clickers.

[Krasi]

Thanks for the input. I belive I understand what I should do.

Here is my current situation:
1. Own weight (w/o gear) - ~87kg, i.e. ~191 pounds. I'll try to loose some in the spring. Way too circular shape these days
2. Static sag - 21mm
3. Race sag - 90-100mm depending on where I sit on the seat.
4. Current outside temp - -7 C (~21 F). First test ride is a good month or two away. It's not uncommon to get as low as -25 C (-13 F) in February.

Once again, thanks for the help, and I'll continue with my theoretical preparetion for the season.

[Skidad]

You need more sag. Check suspension forum.

I would say you're also very close to if not outside the range of the stock springs.

[twowheels]

A couple points to add to Matt's description

Originally Posted by MattR

The low and high speed compression adjusters are slightly misleading. The high speed (larger adjuster nut) is not really "high" speed... but rather it controls motion in a "higher" low speed range or mid speed level. Actual high speed changes are really done by a suspension tuner who revalves the piston and staging of the shim discs. This is largely true. The compression adjusters are working on a valve dealing with fluid displaced by the shock shaft into the reservoir as the shock compresses. The compression stack in the shock body is dealing with fluid moving from one side of the piston to the other. The shaft and the piston obviously move at the same speed, but the fluid velocity is determined by the volume flow divided by the area the fluid travels through. Port sizes, both on the shock piston and between the shock and reservoir determine the actual fluid velocity through each component. The compression stack on the shock piston can have low, medium, and high speed damping elements, but they are not adjustable without disassembling the shock.

These two compression adjusters (low and high) are only changing the oil flow thru a bypass hole. So, when you turn the adjuster screw or nut fully seated, oil is being restricted from flowing thru this bypass hole. It now has to flow through the piston valving. Think of it as water faucet... when you turn the faucet handle closed/off, then the water stops flowing. For suspension, when you make the oil flow more slowly/more restricted... it makes the suspension motion slower and feels more firm. On recent shocks, the low speed compression adjuster is a needle jet, much like a fuel screw or the rebound adjuster. The high speed adjuster actually works on a spring against the compression valve shims, so adding high speed is actually preloading the valve stack making it more resistant to fluid flow into the reservoir.

How do you know if you should tune using the high or low speed compression adjuster? Consider the shock shaft speed, not the motorcycle speed. For a given forward speed, if the wheel has to climb this / the shaft speed is slower than if it has to climb this |. Rolling whoops and G-outs would be considered "low speed" events. Roots, square edged bumps, and jump landings are typically considered "high speed".

A note of caution: The displaced fluid wants to take the path of least resistance. If you crank down on your high speed compression, you're forcing more of the fluid through the low speed port, and you can easily end up with choked flow or orifice damping. The overall damping is a function of the interaction of both flow paths.

[nick790]

So how would you set fast/slow speed adjusted?

Is there a correct order to do it in?

What are we looking to get from each adjuster and in what conditions?

[twowheels]

Originally Posted by nick790

So how would you set fast/slow speed adjusted?

Is there a correct order to do it in?

What are we looking to get from each adjuster and in what conditions?

The short course goes like this -

* make sure your bearings are in good shape, your linkage is lubed, your shocks and forks are reasonably fresh, your tires are adjusted to proper inflation, and your axle is in the middle of its adjustment range.
* measure race sag, adjusting if necessary (see separate posts for proper values). Confirm static sag is in range. If not, install a stiffer or softer spring as appropriate and repeat the process.
* start with the clickers (rebound and slow comp) in the middle of the range, as with the high speed comp knob or adjuster
* warm up yourself and the bike
* if at all possible have someone else watch what the bike is doing and take notes. Ride a small loop a couple of times between each adjustment. Ride at the pace you normally ride or race at!
* adjust one clicker at a time, using large adjustments at first, then narrowing down on your final setting. Remember that every adjustment will affect the function of the others, so this is an iterative process
* adjust the rebound damping first, dialing in enough that you don't bounce after dropping off a small curb. Lighter rebound tends to be best, so use just enough to control the "springy-ness" of the bike. Too much will lead to packing and sensations of harshness as if there were too much compression damping
* attempt to ride over the same set of roots or square edged bumps at a consistent speed, dialing out enough high speed compression to eliminate harshness while still controlling pitch. Try a jump to see if you've created a bottoming issue. If so, dial in more damping.
* ride through some rolling whoops at speed and watch behavior of the bike on jump faces. If you're bottoming in these cases you need more low speed compression.
* look at your notes to make sure you've headed in the right direction and toward your optimum ride
* if you think you've got the ride dialed, go on a longer loop to see how it all comes together
* if your bike is still not behaving as you think it should, carefully craft a description of what it's doing under what conditions and what settings you ended up with, and then dig into the internals

Hope that helps.

[nick790]

Thanks,

Trying to get my sachs shock to feel like my old ohlins one.

[Hrosiiik]

Originally Posted by Krasi

I'm starting with all the appologies in the world for the lame question I'll ask - which clicker does what?

Here are pictures of my suspension (09 EC300):

Pic 1 - Front Top


Pic 2 - Front Bottom

hallo,
i just whant to ask. What fork is in the picture? I have same forks, but no stiickers on it. I dont know what fork do I have.

Sorry for my english.

Filip