Helpful Suspension Set Up Tips

Suspension is hard to understand. Especially if you’re somewhat of a novice when it comes to setting up your bike. It took me a long time to understand what my bike was doing and how I could make it better. If you’re struggling to set up your suspension or maybe you just want to arm yourself with some knowledge, here are some tips to help you when you’re in your garage or out on the track.

Adjustments are there for you to “customize” your set up and feel on the track. The compression and rebound damping adjustments on your machine are known as your “clicker” adjustments. Making the correct changes with your clickers will make your bike handle better and give you a friendlier riding experience. Clickers control the amount of oil flow that is allowed to bypass your fork/shock valving stack. They work like a fuel screw and can fine tune your suspension.

A shock has both low-speed and high-speed compression adjustments. The low-speed adjuster controls the damping at low shock speed velocities like rolling whoops and acceleration bumps. The high-speed adjuster controls damping when the shock is moving at high speeds like g-outs, jump faces and can affect the ride height of the machine. If you’re on an older KYB PSF2 fork (may god be with you by the way) you’re stuck with high and low speed compression and high and low speed rebound. Before you start messing around with clicker adjustments here are some things you should do first:

Check where your clickers are set at and write them down.

Start out with recommended stock settings first for baseline.

Adjust your tire pressure for the type of riding and terrain. 13-14 psi is usually standard.

Make sure you have the correct spring rate for your weight and set your sag.

Bleed the air out of the forks every time you ride, if you have a spring fork.

If using air forks, makes sure to check air pressure and if you’re on AER forks, there is an air bleed for them as well.

Start off by riding your machine with your clickers set in the stock position. This will give you a good base setting of how your bike handles. Ride only a few laps (2-4) at a time when you try new settings so you will not be second guessing your initial impression of each adjustment. When you stay out too long you will start to second guess your initial thoughts. Ride the same lines/bumps every lap so you get a feel for the changes you make and do not ride around the bumps you are trying to test on. If you change lines this will alter your perception of how well your stuff is working. Cheating doesn’t nothing for you here! This will only hurt you in the long run, so buck up and take the rough line! Make changes to your clickers 1-2 “clicks” at a time and one adjustment at a time (rebound or compression). Changing compression and rebound on the fork and shock at the same time can confuse you as to what setting is actually improving your machine. There is the old 2 for 1, which is for every two clicks of compression you go in or out on rebound. For example, if you’re on a KYB spring fork and you go two clicks in stiffer, you might want to back out one click of rebound to compensate for the stiffer comp setting. For beginners, just chill down and do one adjustment at a time. Soft terrain usually requires more compression damping (stiffer) because the bumps are softer in nature and usually taller. Same goes for when the bumps are soft/big and spaced further apart, so in that situation the machine can require a slower rebound damping to minimize kick. If there is a hard base underneath, the bumps will usually be closer together and square edges will develop. In this case a softer/faster setting can be used, especially when speeds are higher.

 You can also run your front end higher (drop your fork height) and the rear end lower (higher sag number) if possible for stability, to combat any twitchiness your bike may have.

On hard pack dirt it is better to adjust the rebound and compression to a softer setting while still maintaining control and bottoming resistance. Try to find a happy medium between bottoming and comfort. It’s ok to bottom out once or even twice a lap, so don’t freak out if you bottom out once in a while. That doesn’t mean you need to stiffen your suspension if you’re bottoming out. All of your suspension is meant to be used, that’s why it’s there, so let it do its job. If you are bottoming out more than that, you would adjust your compression clickers to a stiffer setting. Adjusting your rebound damping to a stiffer setting will help if your bike feels unstable (loose feel) or if you are blowing through the stroke on jump faces. In very rare cases adjusting the rebound clicker one way or the other could work. While it is common to stiffen the shock rebound when your bike kicks over bumps (because you feel like it’s bucking you), many times it is caused by compression that is too stiff. Try going one or two clicks softer/faster to see if it soaks up the bumps and calms the chassis down. If that doesn’t seem to help check your riding position on the bike or yes, it could be that your rebound is too fast/soft. Getting the shock to not “kick” on top of jumps is difficult to diagnose so be ready to try both sides of the spectrum with rebound on this type of tricky obstacle.

Again, be patient. Designate a day where you just play around with your settings and get familiar with your bike. I feel like suspension tuning is kind of like dating. You must learn your partner before you can get married right? Getting a balanced, comfortable suspension setting is no different than dating. Get to know your bike before you decide to dump it and blame it all on her. Maybe it’s you? Maybe you didn’t give it a chance? Play around and see what works for you. If the rear of your bike kicks to the side, the cause can be that it’s too stiff of a setting. Again, try one adjustment at a time. Lack of traction (wheel spin) on acceleration bumps can usually be improved by softening the low-speed compression on the shock or speeding up the rebound, so the rear tire follows the ground better. Keep in mind that faster riders generally prefer stiffer settings to maintain control at speed (performance) while slower riders prefer softer settings for comfort

When it comes to air forks messing with the air pressure can be a pain. Just to let all you know, 2 psi is one full spring rate on any air fork, so that is why I usually adjust using “bar”, not psi. How many times have you changed a spring out at the track? Not very much right? Unless you are very light or on the heavier side, the stock air pressure settings from the factory are usually a great place to start and keep within .2-.4 bar (softer or stiffer). Adjusting your compression and rebound clickers on air forks is much easier and a simpler way to dial in these types of forks. Air pressure will change throughout the day as heat builds up, so if you are checking your air pressure in the middle of the day, make sure the fork is cooled down to ambient air temperature.

Follow some of these easy steps and I can guarantee you that you will get your set up even better and enjoy riding that dirt bike of yours even more. If you have any set up questions you can email me at kris@keeferinctesting.com as we will always try to be here for you!

Action And Reaction (Shock)

With every action there is a reaction right? This is no different when it comes to dirt bikes and the mechanics of each change/adjustment. Since suspension is always a hot topic with motocross machines, I thought why not give you guys some insight on what each change point/adjustment available to you is on the shock, as well as what it can do out on the track (good or bad). The action of one change can have reaction on the opposite end of the machine as well, not just the focused area. Here is a breakdown of action and reaction, shock edition. If you’re looking for the “fork” portion of this article, check it out here: https://www.keeferinctesting.com/offroad-testing/2021/6/22/action-and-reaction-fork

Shock: 

Low Speed Compression: Low speed compression damping will allow your shock’s stroke to stiffen or soften when compressed at lower load situations. 

Action/Stiffer: Stiffening the LSC can allow your bike’s ride attitude to be flatter with less pitching on/off throttle, can help with wallow feeling through rollers, can help keep rear end down on initial bump impact, bump absorption can improve if shock is riding too low in the stroke, give the rider a firmer feel to allow them to ride more aggressively (more performance).

Reaction/Stiffer: Going too stiff can cause harshness or a too firm feel when hitting bumps, can cause deflection when shock is light in its stroke (off throttle situations), can cause less rear wheel traction (especially on lean angle), can give rider a less plush feel on bump impact, less movement in rear end which can give a rigid feel through seat, can overpower fork and allow bike to be front end heavy down hills.

Action/Softer: Softening the LSC can increase plushness, allow the shock to move further down in the stroke under load or increase comfort on initial bump impact, make the action of the stroke faster, can increase rear wheel traction (especially on lean angle), give a more supple feel through the seat when accelerating out of choppy corners. 

Reaction/Softer: Allow the shock to go through stroke too much (low rear feel), which can create a fast moving rear end feel, less damping feel on bump impact, create a low rear end feel that allows the rear end to kick you on braking bumps (which can make transfer of weight to front end, too abrupt off throttle), oversteering through area 2 of corners because rear end unloads to fast on de-cel which causes front end to knife, make fork feel too high on throttle, which can make fork deflect, causes shock tp bottoming more than 2-3 times per lap.

High Speed Compression: High speed compression damping will allow your shock’s stroke to stiffen or soften when compressed at high-speed load situations, but can also can act like a secondary ride height.  

Action/Stiffer: Depending on if you’re a Showa, KYB, or WP rider will depend on how much you will want adjust the HSC knob to feel a difference. A Showa shock is more sensitive to turns than that of a WP or KYB shock. I would adjust HSC on a Showa shock by 1/6 turns to feel a difference versus a 1/4 turns on a WP/KYB shock. Going to a stiffer HSC setting on your shock will raise your rear end and give you more hold up in g-outs, up faces of jumps, out of corners (on-throttle) as well as create more front end bite when entering into corners (area 1-2). Adjusting the high speed is sometimes scary to weekend riders, but shouldn’t be feared as it is one of the most notable changes you can make to your shock. Adjusting the HSC can give a  rider a plusher feeling if he/she is too low in the stroke. Increasing HSC can get you out of the harsh portion of the shock’s stroke if you’re too low on accel/de-cel. HSC can make the ride attitude of the bike more balanced front to rear.

Reaction/Stiffer: Negative affects of going stiffer on HSC can range from deflection on/off throttle, rigidity feeling up, low front end feel, too firm of a feel when hitting bumps on acceleration, harsh feeling through your feet, oversteer (knifing on lean angle), allow the bike’s ride attitude to be too front end low/rear end high and cause kicking on de-cel as well as nose end heavy off jumps.

Action/Softer: Softening the HSC can increase plushness on braking bumps, give the bike a flatter overall feel when chopping throttle in soft dirt, allow the shock to move further down in the stroke under heavy load, make the action of the stroke faster (less damping feel), can increase rear wheel traction (especially on lean angle/more tire contact patch), give a more supple feel to the hands through the pegs. 

Reaction/Softer: Allow the fork to ride too high in the stroke, can cause front end pushing through corners, fork deflection, create a low rear end feel that can make the rear of the bike wallow through rollers/waves, causes too much pitching on/off throttle (teeter totter movement), harsh feeling (firm) around the track because the shock is riding in the stiffer part of the stroke/damping (mid-stroke), unbalanced feel around track (more comfort in rear end with less comfort on fork). 

Rebound: The rebound damping allows the shock’s shaft to move faster/slower when compressed/released. It can also act as a type of damping force as well. 

Action/Faster: More rear end traction because the shock is moving faster, which in turn is causing the rear tire to get back to the ground quicker over bumps/square edges, can help straight line stability, can increase plushness through the beginning to mid stroke, can help get more lift off jumps.  

Reaction/Faster: Can cause side to side movement on throttle under slight lean angle (edge of tire), could make shock feel too soft/low on acceleration bumps (diving), can cause pushing sensation of rear tire through area 2-3 (middle to end) under throttle, can put too much weight on front end through corners.

Action/Slower: Can allow for more damping feel (firmer), slow the rear end down off throttle which can give you increased front end traction in ares 2 (middle) of corners, more planted feeling coming into deep braking bumps, less movement of the initial stroke/under throttle while hitting acceleration bumps, can allow bike to soak up jump faces more (less air).

Reaction/Slower: Can give rider a harsher feeling on/off throttle when hitting bumps, could make shock feel too firm on acceleration through choppy bumps (too high/harsh), can give less rear wheel traction on hard pack chop, front end high feel off jumps, can cause a ride attitude that is too low off throttle, that low feeling can give the rider less cornering stability through choppy ruts because it will pack and give the front tire less contact patch.

Sag: The sag measurement is important because it gives the correct preload on the shock spring for your weight. Sag is also important because it gives the bike its intended ride attitude when designed. 

Action: Getting the correct ride height (or sag) is crucial because when the bike is designed, it’s designed with the a certain amount of preload. The chassis will not act like it is intended (when developed) if the sag is not set to the correct setting. Having the correct sag will give you the ride attitude/balance around the track. 

Reaction: If you’re sag is too high, the rear of the bike can be harsh/deflect on square edge, cause the front end to be too heavy (or low feeling) off throttle, front end oversteer in corners, as well as give the balance of the motorcycle a stinkbug feel. Having the sag too low can allow your front end to be vague in corners (less front end bite), give the rider less rear wheel traction out of corners (under load) and could even cause more pitching on/off throttle. If you’re looking for a little more front end bite or more front end steering then try going up slightly (less sag) on your preload. If you want more stability on faster tracks or on deep sand tracks try going with more sag (rear end lower) for increase stability and a less front end heavy feel.