Some real basics for a suspension novice!

[syko]

Hi guys,
hope someone can help me here. i've already done forum searches and am struggling to find the answers I need so sorry if I am repeating questions that have already been asked.

i am the proud owner of an 06 crf250, awesome bike, i've been out the saddle for a few years through injury but now i'm slowly finding my feet and getting faster each week.
the bike geneally handles great for my ability but the suspension feels so harsh, really hard and is just battering me on the track.

when it comes to suspension i haven't got a clue, rebound, compression and damping are all scary words to me, i am lost.

generally the tracks over here are pretty hard pack with lots and lots of very small bumps, braking bumps and tons of small ruts that criss cross everywhere (this is usually because here in england the weather is wet in the mornings during practice which cuts the track up bad then as the sun comes out and bakes it, the bumps and ruts dry out and become really hard )

I find that in these conditions my bike grips very well, but it feels so hard, my body and especially my arms seem to take all the punishment, my bones literally rattle.

I've set the sag, but now i need to find out how to get the suspension set up better, I haven't really got the money to spend on expensive tune ups so i'm really looking for some tweaks I can do myself.

so..
what is rebound
what is compression
what is damping and where do i adjust these on the bike.

and
what kind of settings should i be looking to adjust and what kind of adjustments?


I'd really appreciate simple basic terms to help me find my feet guys.
any more infor you need let me know.

thanks in advance.

 

[syko]

Also,
just flicking through my manual and the terminology confuses me a little.
if it says reduce/increase the rebound, which term means go softer or harder?

 

[Crzyfrlss1]

Go to factoryconnection website.

click on setup tips.

That should get you started.


Cant post the web address, I'm still a newbie around here. It's got dot-com before website posted above.

 

[FruDaddy]

Rebound is the extension of the forks and shock.
Compression is just that, the compression of the forks and shock (opposite of rebound).
Damping is the way the compression and rebound is controlled by the fluid. This is what is adjusted by the clickers. Sorry for the bad definition, but it's one of those thing that I know but can't really define well.
There are screws at the tops and bottoms of the forks and shocks (clickers), the exact location should be pointed out in your manual. When adjusting the forks, make sure to adjust both sides evenly. Make small changes and see how it feels. If it gets worse, go the other way. If you have a buddy that you can trust, have that buddy make blind changes so you won't experience the placebo effect. As far as increasing/decreaseing the rebound, if the shock is rebounding too fast, you want to soften it, I think this is decreasing, but if I am wrong, somebody here will be happy to correct me. Until then, think of it as increasing or decreasing the damping in the shock.
I expect you will soon get better answers, but I do hope this helps a little.

 

[robwbright]

Jeremy Wilkey 01-03-2002 08:40 PM

--------------------------------------------------------------------------------

Offroad Tuning

We feel that understanding the basic suspension tuning can give you an advantage over your competition, or simply make your riding experience much better. For this reason we have included a breakdown of basic suspension tuning and common problems experienced while setting up bikes for different terrain and riding conditions.

Remember: different conditions require slightly altered settings. MX-TECH guarantees all of its work. If you happen to run into any set-up problems, make sure you call immediately; we are committed to giving you complete satisfaction!

Race sag:

Set the race sag in the range listed on your spec sheet. This is the most important of the suspension settings. After you have spent some time and gotten the other circuits dialed in, you can try some different sag measurements to create a distinct feel and weight bias. As a general rule you should use about one third of your available travel as sag.

Free sag:

(This measurement is not needed if you have had your suspension set-up by MX-TECH because our suspension is completely different.) This measurement is taken to determine if you have the proper spring rate for your weight. Observe the characteristics of the motorcycle under its own weight. If the bike tops out or has less than 3/4 of an inch of sag then the spring is too soft! If the bike sags drastically under it's own weight, then it has too stiff a spring rate. If you have any questions about any of this or it doesn't seem to make sense, contact us immediately; well get you straightened out!

Now that you have got your spring set, you can get to the fun part: Riding your motorcycle!

Getting started, shock:

Your MX-TECH suspension should have relatively close settings when it arrives at your door! However, there are minor differences in riders from day to day; this unpredictable difference requires set-up by the customer. We hope this helps get you in the ballpark if your using stock suspension. If you are having troubles dialing in your revalved MX-Tech suspension, again, contact the shop immediately.

Setting the rebound:

1.) Find a relatively fast trail with braking bumps, rocks and roots leading into the entrance of a corner. Reduce (Turn clicker out) the rebound damping until the rear end begins to hop or feel loose. Finally, increase (Turn clicker in) the rebound damping until the sensation goes away.

2.) Find a log or ledge that tends to bounce the motorcycle after hitting it. If the rear end bounces up uncontrollably, add rebound. (Turn clicker in)

3.) Find some large whoops. The motorcycle should track straight through the whoops with the rear wheel extending to the ground before the next impact. If it does not perform as described, as above, it is packing and the rebound dampening should be reduced! (Turn clicker out) (Please note the guide for sand set-up, as these rules don't apply for sand.)

4.) Find a corner with acceleration bumps, rocks, and roots on the exit. The rear of the motorcycle should follow the ground. If the rear end "breaks up", reduce the rebound. (Turn clicker out) (If this fails soften the compression two clicks.) (Turn clicker out)

Setting the compression:

1.) Find some rough sections, a large jump and a couple of "G-Outs". The shock should bottom on the roughest section but it should not be a slamming sensation. Add compression to fight bottoming. (Turn clicker in.) But avoid going to far as the suspension's ability to react to small variations of surface and rocks will be sacrificed in the trade. Remember the adjusters have a primary effect on the low speed, so even a large change in setting may only effect bottoming resistance slightly. Remember bottoming your suspension is not necessarily a bad thing. You should strive to bottom off the biggest bottoming load obstacle on the trail. If you don't you're not getting maximum plushness from your suspension. Run your suspension as soft as you can get away with but remember that if the trail has sand sections or lots of g-loads this will work against you.

Getting started, forks:

Setting the compression:

1.) The forks should react to all trail variations. If the forks seem harsh on small bumps, holes, rocks, or roots soften the compression. (Turn clicker out) If they are relatively smooth, stiffen (Turn clicker in.) until they do feel harsh and then turn back a click or two.

2.) Now find the rough part of the trail again. The forks should bottom over the worst g-load or jump. If harsh bottoming occurs, add oil in 5-mm increments.

Setting the rebound:

The rebound damping is responsible for the stability and the cornering characteristics of the motorcycle.

1) Find a short sweeper. When the forks compress for the turn, the speed at which the forks return is the energy that pushes your front wheel into the ground. If the forks rebound too quickly, the energy will be used up and the bike will drift wide, or wash. If the rebound is too slow, the bike will tuck under and turn too soon to the inside.

2). With the bike turning well, the wheel should return to the ground quickly and not deflect off successive impacts. If it does, reduce the rebound. (Turn out)

Guidelines for different conditions:
For hardpack to intermediate:

Set the compression softer, (Turn clicker out) front and rear to help get maximum wheel contact and plushness.

Sand conditions:

(Non-square edged bumps); More low speed compression and rebound are necessary. Start by adding 1-2 clicks (Turn clicker in.) of rebound and as the track gets rough, add compression 1-4 clicks. (Turn clicker in.) (Supplementary sand set-up techniques). Harshness is a result of packing in forks. Remember to add compression (Turn clicker in) to help keep the front end from packing The rear suspension will exhibit packing by swapping. To eliminate swapping begin adding compression (Turn clicker in) until the bike tracks straight and then add rebound (Turn clicker in) to keep the rear following the terrain of each whoop. Don't be concerned if your clickers are nearly maxed out in sand conditions. Unless of course you had your bike revalved for sand.

Rocks and Roots:

Rocks and roots will make your suspension work at it’s worst. Try reducing compression till the suspension can react and not deflect off every impact.

Unpleasantries?

Head shake:

Adjust the forks lower in the triple clamps. If that does not improve the suspension then reduce the rebound on the front fork. (Turn out)

Excessive rear end kick:

Check for packing, which is identified by kick to side in hard to loam conditions. If you observe packing, soften rebound. (Turn clicker out.) This can not be avoided if you brake improperly and lock the rear wheel up and/or pull in the clutch, on the entrance to corners.

Keep a record of the conditions and the different settings if you ride in different areas. That way you can start at a point that worked well the previous times.

General Ideas:

MX-TECH Offroad suspension is designed so you have a decent amount of low-speed compression so you will have decent stability and control of your motorcycle, with a absolute minimum of highspeed compression for a plush reaction to sharp spikes of shaft movement. Remember that if you make the suspension too soft you will use lots of energy just maintaining direction, and control. Be careful when you set it, there is a difference between soft and plush. Soft is often hard to control and harsh, while plush is smooth and controlled. The goal is to maximize control and comfort. Think about the entire section of trail or the average conditions of the trail. Factor in your skills as a rider and then select the setting that will provide the best overall ride characteristics. Consider that in offroad riding you will encounter an incredibly wide range of conditions and you’ll need to shoot for the middle ground or your suspension will be very good in some sections and very poor in others.

Maintenance:

The dampening of suspension changes as the components are used. This is caused by wear and oil viscosity breakdown. It is important that your suspension has regular maintenance by MX-TECH. Improper assembly or inadequate fluids will drastically alter the way these components were designed to perform.

For the shock, we recommend that the linkage be cleaned and greased once a month. The shock's oil should be changed every 3-6 months. Seals will generally last a season, so once a year we recommend replacing them.

For the forks, we recommend that you bleed off the gas pressure once a week. Oil should be changed once a month. A complete service is suggested every 3 months. Seals will usually last 3 months, if they are not contaminated with dirt and water. Don't wash anywhere around your seals with power washer (including the chrome.) Also we do not recommend removing dust scrapper for internal cleaning. This typically frees up dirt caught in the scraper, which will attack the oil seal.

----------------------------------------------------

AND

_SOLO_ 09-20-2001 12:46 AM

--------------------------------------------------------------------------------

Here you go, I think this is what you are looking for, I've been saving it for a while.


Set-your sag!
Then start with the shock:
Setting the rebound:
1.) Find a relatively fast straight with braking bumps leading into the entrance of a corner. Reduce the rebound dampening until the rear end begins to hop or feel loose. Finally, increase the rebound dampening until the sensation goes away.

2.) Find a jump that tends to launch the motorcycle out. The rear end should absorb and then smoothly lift the motorcycle into the air. If the rear end bounces up, add rebound.

3.) Find some large whoops. The motorcycle should track straight through the whoops with the rear wheel extending to the ground before the next impact. If it does not perform as described, as above, it is packing and the rebound dampening should be reduced! (Please note the guide for sand set-up, as these rules don't apply for sand.)

Setting the compression:
1.) Find a corner with acceleration bumps on the exit. The rear of the motorcycle should follow the ground. If the rear end "breaks up", soften the compression. (If this fails soften the rebound two clicks.)

2.) Find some rough sections, a large jump and a couple of "G-Outs". The shock should bottom on the roughest section but it should not be a slamming sensation. Add compression to fight bottoming. But avoid going too far, as small bump ride will be sacrificed in the trade. Remember that the adjusters have a primary effect on the low speed, so even a large change in setting may only effect bottoming resistance slightly. Keep in mind, bottoming your suspension is not necessarily a bad thing. You should strive to bottom off the biggest bottoming load obstacle on the track. If you don't,you're not getting maximum plushness from your suspension.

Getting started, forks:
Setting the compression:

Note: if your forks were shipped or laid on their side they need to be pumped about ten times to replenish the cartridge.

1.) The forks should react to all track variations. If the forks seem harsh on small bumps or holes, soften the compression. If they aren't, stiffen until they do feel harsh and then turn back a click or two.

2.) Now find the rough part of the track again. The forks should bottom over the worst obstacle. If harsh bottoming occurs, add oil in 5-mm increments.

Setting the rebound: The rebound dampening is responsible for the stability and the cornering characteristics of the motorcycle.

1) Find a short sweeper. When the forks compress for the turn, the speed at which the forks return is the energy that pushes your front wheel into the ground. If the forks rebound too quickly, the energy will be used up and the bike will drift wide, or wash. If the rebound is too slow, the bike will tuck under and turn too soon to the inside. Find the appropriate balance for each track.

2). With the bike turning well, the wheel should return to the ground quickly yet not deflect off berms or bounce off jumps.

Going to different tracks:

For hardpack to intermediate:
Set the compression softer, front and rear to help get maximum wheel contact and plushness.

Sand tracks:

(Non-square edged bumps); more low speed compression and rebound are necessary.

Start by adding 1-2 clicks of rebound and as the track gets rough, add compression 1-4 clicks. (Supplementary sand set-up techniques). Harshness is a result of packing in forks. Remember to add compression to help keep the front end from packing. The rear suspension will exhibit packing by swapping. To eliminate swapping begin adding compression until the bike tracks straight and then add rebound to keep the rear following the terrain of each whoop. Don't be concerned if your clickers are nearly maxed out in sand conditions. Unless of course you had your bike revalved for sand.

Supercross:

(G-load, curb hits); G-loads produce slow piston speeds. This means that less dampening is produced by the shock and forks in a situation that causes more of a bottoming load. To set your bike up for Supercross adjust the compression stiffer on the suspension (2-6), clicks and in some circumstances raise oil level and/or change to stiffer springs.

Unpleasantries?

Head shake:

Adjust the forks lower in the triple clamps. Excessive rear end kick: Check for packing, which is identified by kick to side in hard to loam conditions. If you observe packing, soften rebound. This can not be avoided if you brake improperly and lock the rear wheel up and/or pull in the clutch, on the entrance to corners. Keep a record of the different settings if you race different tracks. That way you can start at a point that worked well the previous times.

 

[FoxRocks]

oh man, that was a great write-up on suspension.

Thanks!

~FOX~