Motorcycle Suspension Guide

The suspension setting process is a way to update you current suspension to the style of riding to best suit your needs.  When suspension works correctly the bike will be much more enjoyable to ride by isolating the rider from the road, and to expand your abilities while exploring new limits, and know how to adjust and improve how it works. We at Superbike-Coach know about the value and we are willing to share this knowledge with this guideline and in our ‘Suspension Workshop & Track Time‘ classes. Anyway, here is your Superbike-Coach motorcycle suspension troubleshoot guide:

DAMPING 

Here are some basic symptoms of suspension damping problems that you might find affecting your bike. Remember these are extreme examples; your symptoms may be more subtle. You may also have to find an acceptable compromise on either end of the adjustment spectrum.

Front End

LACK OF REBOUND 

The fork offers a plush ride. When the pace picks up, however, the feeling of control is lost. The fork feels mushy, and traction feel is poor. After hitting bumps at speed, the front tire tends to chatter or bounce. When flicking the bike into a corner at speed, the front tire begins to chatter and lose traction. This translates into an unstable feel at the clip-ons. As speed increases and steering inputs become more aggressive, a lack of control begins to appear. Chassis attitude and pitch become a real problem, with the front end refusing to stabilize after the bike is counter steered hard into a turn.

– Understeer!
– The front can feel unstable.

Symptoms: Forks are plush, but increasing speed causes loss of control and traction
The motorcycle wallows and tends to run wide exiting the turn causing fading traction and loss of control.
When taking a corner a speed, you experience front-end chatter, loss of traction and control.
Aggressive input at speed lessons control and chassis attitude suffers.
Front end fails to recover after aggressive input over bumpy surfaces.

Solution: Insufficient rebound. Increase rebound gradually until control and traction are optimized and chatter is gone.

TOO MUCH REBOUND 

The ride is quite harsh–just the opposite of the plush feel of too little rebound. Rough pavement makes the fork feel as if it’s locking up with stiction and harshness. Under hard acceleration exiting bumpy corners, the front end feels like it wants to wiggle or tank slap. The tire feels as if it isn’t staying in contact with the pavement when on the gas. The harsh, unforgiving ride makes the bike hard to control when riding through dips and rolling bumps at speed. The suspension’s reluctance to maintain tire traction through these sections erodes rider confidence.

– Oversteering!
– It will give poor grip of the front tire.
– It feels like the front wheels will tuck under in corners.

Symptoms: Front-end dives severely, sometimes bottoming out over heavy bumps or during aggressive breaking.
Front feels soft or vague similar to lack of rebound.
When bottoming, a clunk is heard. This is due to reaching the bottom of fork travel.

Solution: Insufficient rebound. Decrease gradually until control and traction are optimized.

LACK OF COMPRESSION 

Front end dive while on the brakes becomes excessive. The rear end of the motorcycle wants to come around when using the front brakes aggressively. The front suspension “bottoms out” with a solid hit under heavy braking and after hitting bumps. The front end has a mushy and semi-vague feeling–similar to lack of rebound damping.

– Strong diving of the front.

Adjustment advice: Compression damping should be adjusted together with front fork oil level.

Symptoms: Front-end dives severely, sometimes bottoming out over heavy bumps or during aggressive breaking.
Front feels soft or vague similar to lack of rebound.
When bottoming, a clunk is heard. This is due to reaching the bottom of fork travel.

Solution: Insufficient compression. Increase gradually until control and traction are optimized.

TOO MUCH COMPRESSION 

The ride is overly harsh, especially at the point when bumps and ripples are contacted by the front wheel. Bumps and ripples are felt directly; the initial “hit” is routed through the chassis instantly, with big bumps bouncing the tire off the pavement. The bike’s ride height is effected negatively–the front end winds up riding too high in the corners. Brake dive is reduced drastically, though the chassis is upset significantly by bumps encountered during braking.

– Good result during braking.
– Feels harsh over the bumps.

Symptom: Front end rides high through the corners, causing the bike to steer wide. It should maintain the pre-determined sag, which will allow the steering geometry to remain constant.

Solution: Decrease compression gradually until bike neither bottoms or rides high.

Symptom: Front end chatters or shakes entering turns. This is due to incorrect oil height and/or too much low speed compression damping.

Solution: First, verify that oil height is correct. If correct, then decrease compression gradually until chattering and shaking ceases.

Symptom: Bumps and ripples are felt directly in the triple clamps and through the chassis. This causes the front wheel to bounce over bumps.

Solution: Decrease compression gradually until control is regained.

Symptom: Ride is generally hard, and gets even harder when braking or entering turns.

Solution: Decrease compression gradually until control is regained.

REAR SHOCK

LACK OF REBOUND 

The ride is plush at cruising speeds, but as the pace increases, the chassis begins to wallow and weave through bumpy corners. This causes poor traction over bumps under hard acceleration; the rear tire starts to chatter due to a lack of wheel control. There is excessive chassis pitch through large bumps and dips at speed and the rear end rebounds too quickly, upsetting the chassis with a pogo-stick action.

– The rear tops out too fast under braking, causing the rear wheel to jump
– The bike feels unstable.

Symptoms: The ride will feel soft or vague and as speed increases, the rear end will want to wallow and/or weave over bumpy surfaces and traction suffers.
Loss of traction will cause rear end to pogo or chatter due to shock returning too fast on exiting a corner.

Solution: Insufficient rebound: Increase rebound until wallowing and weaving disappears and control and traction are optimized.

TOO MUCH REBOUND 

This creates an uneven ride. The rear suspension compliance is poor and the feel is vague. Traction is poor over bumps during hard acceleration (due to lack of suspension compliance). The bike wants to run wide in corners since the rear end is “packing down”; this forces a nose-high chassis attitude, which slows down steering. Rear end wants to hop and skip when the throttle is chopped during aggressive corner entries.

– Rear jumps on the bumps instead of following the surface.
– The rear chatters under braking.
– It holds the rear down with the result that the bike will understeer!
– It can cause overheating in the hydraulic system of the shock
absorber and make it fade, in other words, it will loose damping
when hot

Symptoms: Ride is harsh, suspension control is limited and traction is lost.
Rear end will pack in, forcing the bike wide in corners, due to rear squat. It will slow steering because front end is riding high.
When rear end packs in, tires generally will overheat and will skip over bumps.
When chopping throttle, rear end will tend to skip or hop on entries.

Solution: Too much rebound. Decrease rebound gradually until harsh ride is gone and traction is regained. Decrease rebound to keep rear end from packing.

LACK OF COMPRESSION 

There is too much rear end squat under acceleration; the bike wants to steer wide exiting corners (since the chassis is riding rear low/nose high). Hitting bumps at speed causes the rear to bottom out, which upsets the chassis. The chassis attitude is affected too much by large dips and G-outs. Steering and control become difficult due to excessive suspension movement

– The rear wheel start to bump sideways under acceleration out of the corner.
– The bike will squad too much (rear is too low), that will cause the front to loose grip..

Symptoms: The bike will not turn in entering a turn.
With bottoming, control and traction are lost.
With excessive rear end squat, when accelerating out of corners, the bike will tend to steer wide.

Solution: Insufficient compression. Increase compression gradually until traction and control is optimized and/or excessive rear end squat is gone.

TOO MUCH COMPRESSION 

The ride is harsh, though not quite as bad as too much rebound; the faster you go, the worse it gets, however. Harshness hurts rear tire traction over bumps, especially during deceleration. There’s little rear end “squat” under acceleration. Medium to large bumps are felt directly through the chassis; when hit at speed, the rear end kicks up.

– The rear wheel to slide under acceleration .
– It can give a harsh ride over bumps.

Symptoms: Ride is harsh, but not as bad as too much rebound. As speed increases, so does harshness.
There is very little rear end squat. This will cause loss of traction/sliding. Tire will overheat.
Rear end will want to kick when going over medium to large bumps.

Solution: Decrease compression until harshness is gone. Decrease compression until sliding stops and traction is regained.

Spring ratio

Rear

Too hard spring ratio:
– Gives easy turning into corners.
– Makes the rear feel harsh.
– Create poor rear wheel traction.

Too soft spring ratio:
– Gives good traction in acceleration.
– Creates understeer in entry of corner.
– Makes too much suspension travel which will make it difficult to flick the bike from one side to the other in a chicane.
– Will give a light feeling in the front.

Front

Too hard spring ratio:
– Good under braking.
– Creates understeer.
– It feels harsh in the corners.

Too soft spring ratio:
– Gives easy turning into corners.
– Creates oversteer.
– Can cause front to tuck under.
– Bad under braking (diving).

Front fork oil level

First see manual. The modern front fork of cartridge type is very sensitive for oil Level changes, because of the small air volume Air inside the front fork works as a spring. The different level of oil effects the spring ratio from the middle of the stroke and has a very strong effect at the end of the stroke.

When the oil level is raised: The air spring in the later half stage of travel is stronger, and thus the front forks harder.

When the oil level is lowered: The air spring in the later half stage of travel is lessened, and thus the front forks are softer. The oil level works most effectively at the end of the fork travel.

Suspension Tuning 

Limitations

The factories plan on designing a bike that works moderately well for a large section of riders and usages. To accomplish this as economically as possible, manufacturers install valving with very small venturis. These are then matched to a very basic shim stack which creates a damping curve for the given suspension component. At slower speeds this design can work moderately well, but at higher speeds, when the suspension must react more quickly, the suspension will not flow enough oil, and will experience hydraulic lock. With hydraulic lock, the fork and/or shock cannot dampen correctly and handling suffers.

The solution is to re-valve the active components to gain a proper damping curve. It does not matter what components you have, matching them to your intended use and weight will vastly improve their action. Furthermore, if you can achieve the damping curve that is needed, it does not matter what brand name is on the component. Often with stock components, when you turn the adjusters full in or out, you do not notice a difference. In part, this is due to the fact that the manufacturer has put the damping curve in an area outside of your ideal range. Also, because the valves have such small venturis, the adjuster change makes very little difference.

After re-valving, the adjusters will be brought into play, and when you make an adjustment, you will be able to notice that it affects the way the way the fork or shock performs. Trying to figure out a handling problem can be tricky. It’s hard enough dealing with the intricacies of spring preload, rebound damping, etc., but when a definite problem forces you to back off the throttle and take notice, trying to determine the root cause of a handling difficulty can be downright baffling. Is it the front or rear causing it?

And how do I know if rebound or compression damping adjustments will help? In this section, we’ve come up with some of the most common handling complaints that afflict the average rider. Some of these problems occur entering the corner, some of them happen in mid-corner, and others can even cause difficulty exiting a corner. Take a close look at the various problem scenarios we’ve listed and see if one of them sounds similar to a dilemma you’ve been struggling with. Then try our suggested solutions to see if they make an improvement. Remember take it one step at a time, take a test ride after each change, and take notes on whether that change made a difference.

TANKSLAPPER

Problem: A tank slapping bike feels unstable, especially when entering turns. The bars seem to “twitch” excessively whenever a mid-corner bump is encountered. The bars often whip back and forth violently several times (or more) when A tank slapping bike is accelerating aggressively over bumps while coming out of a turn–in other words, a “tank slapper.” The bike steers very easily, although a lack of traction is sometimes noticeable in the rear whenever he tries to accelerate at moderate lean angles. The bike also seems to have a dropped-down, “nose low, rear-end-high” attitude while riding.

Cause: If the bike feels this way, then probably there is too much front end weight bias

Solution: The biggest distinguishing factor in this case is the “nose-low/rear-end-high” chassis attitude feeling. . This not only hinders traction at the rear, but also affects the steering geometry (steeper rake/less trail) and can cause the instability problems. As long as the bike is suspension static sag levels set correctly, the first step is to try less rear spring preload and/or more front preload, to the point just before they begin to affect handling negatively.

You should remember to adjust his rebound damping if necessary (in fact, he should check to see if decreasing the front rebound damping in small increments helps; the forks may be too stiff, hindering traction). If only partially successful, a more drastic step would be changing chassis ride height; this would involve raising the front end by dropping the fork tubes in the triple clamps (if there’s enough material protruding above the top clamp, to ensure front fork structural integrity), and/or dropping the rear by shortening the rear shock (if possible).

Note: We’ve also seen a tank slapping tendency produced by too much rearward weight bias. The bike might try to be working the opposite of the preceding paragraph solution, or check out the understeer/no front traction problem scenario for more suggestions.

FLOATING RIDE 

Problem: Although the bike may have a very smooth ride while riding over potholes and such in the city, once out in the canyons, the bike seems to float over the pavement like a car, with little or no pavement feedback. When he starts to ride aggressively, the bike rocks back and forth excessively, especially during brake/throttle transitions, and the floating feeling becomes even more pronounced. Hard cornering makes the bike feel loose, almost as if it has a hinge in the middle. Mike’s tires might begin to chatter mid-corner when encountering bumps and accelerating over those bumps causes his bike to wallow or weave.

Cause: The problem here is generally not enough rebound damping.

Solution: The ride is smooth and supple at low speeds, but higher speeds generate greater amounts of energy that can’t be dissipated with the little damping available. As a general rule of thumb, if either end is pushed down firmly and quickly by hand, the suspension should return in a smooth, controlled manner without rebounding once or twice before settling down. Try stiffening up the rebound damping in small steps, and remember to do the front and rear separately, not simultaneously; that way he can readily see if one or the other makes a difference. If the rebound damping is cranked up to the maximum and the bike still feels soft and wallowy, you may need to rebuild the suspension components.

REAR-SWAPPING 

Problem: When Richard gets on the brakes aggressively while approaching a corner, the bike’s rear end begins to swap side-to-side, and feels as if it wants to pivot around the front.

Cause: The cause is too much front end weight transfer under braking. The front end is compressing so low that the bike’s weight tries to pivot around the steering head, causing the side-to-side movement.

Solution:   The quickest solutions here are to increase the front fork spring preload and/or raise the front ride height by dropping the fork tubes in the triple clamps, or decrease the rear ride height by shortening the shock (if possible). Try increasing the fork spring preload first, and progressing in small increments until the handling begins to be negatively affected (remember to watch the rebound damping when increasing the spring preload). If that doesn’t work, try the ride height modifications; watch for adverse handling reactions in other areas when doing this as ride height changes drastically affect how the bike corners. Other solutions to try–although less effective–are to increase the compression damping in the forks (if possible), or to decrease rebound damping in the rear (to allow the rear tire to follow the pavement quicker). Again, watch for adverse handling reactions in other riding situations when test riding.

ROUGH RIDING 

Problem: The bike is uncomfortable and he feels every little bump in the road. He doesn’t have any confidence because his bike feels nervous and twitchy, especially over bumpy sections where it doesn’t absorb the bumps, and his tires lose grip easily. Diving into corners during track days, the bike is unstable and jumps around over every little bump and crack in the tarmac.

Cause: The rough ride is most likely due to a generally too-stiff setup–with too much compression and rebound damping.

Solution: First off, the rebound adjusters as outlined in the setup section, and back the compression adjusters out to no more than the middle of their range. This will give a starting point to work from, and get rebound damping in the ballpark. Dialing in the rebound more accurately can be accomplished by riding the bike over a rough section of pavement; the suspension should not pack down (too stiff), nor should the bike be wallowy like a Cadillac (too soft). Riding the bike repeatedly over the same road after making small changes to the damping adjusters is a good way to distinguish between the characteristics and determine a good setting. Once the rebound is set properly, the compression damping can be fine-tuned according to the setup section. Once again, make small changes between test sessions over the same road to feel and compare the different settings.

BOTTOMING 

Problem: When  braking  hard approaching a corner, the front fork bottoms out severely, especially over bumps. However, the fork action and overall bike handling is fine everywhere else.

Cause: The problem here is the ride height is set up correctly for his riding style, but the fork action is obviously too soft whenever weight is transferred to the front (as when hard braking).

Solution:   The from previously stiffened up the fork spring preload, and while it helped with the bottoming problem, it unfortunately made his bike’s chassis attitude too front-end-high, adversely affecting handling. The cure here would be to raise the fork tubes in the triple clamps (starting in increments of 4mm), which lowers the front end; you could then increase fork spring preload without causing the ride height problems mentioned previously. Care should be taken to ensure that the front wheel/fender isn’t getting too close to bottoming out on the lower triple clamp or radiator when lowering the front or raising the fork tubes. If the preload adjuster becomes maxed out during testing and dial-in, a set of heavier rate springs or a larger preload spacer (inside the fork) may be necessary.

HEAVY STEERING 

Problem: The bike’s steering feels super heavy at low speeds, and once he gets his bike turning by using lots of muscle, it practically falls into corners.

Cause: These characteristics could be the result of a squared-off rear tire (too much straight-line riding) or notchy or too-tight steering head bearings;

Solution: if the bike has a steering damper mounted, it may be adjusted too tight. Suspension-wise, heavy steering is a typical result of having rear ride height set too low, raking out the chassis like a chopper.

If the same troubles occur after trying this bike with the steering damper backed off, checking his tire and adjusting his steering head bearings, the problem is most likely in his bike’s chassis attitude. Front and rear sag should be checked and set correctly, followed by another ride to check for any changes in handling. If there is little or no change, gradually change the geometry by either raising the fork tubes in the triple clamps or–and has a rear ride-height adjuster–raising the rear of his bike. When dropping the front end of a bike by adjusting fork height, it’s a good idea to keep an eye on clearance between the front tire and radiator, and also–on a conventional fork–to ensure the sliders don’t bottom out on the lower triple clamp.

UNDERSTEERING 

Problem:  Trouble with the bike’s front end, especially while exiting turns, where the front tire loses traction and pushes to the point where it’s washed out. The steering is a bit heavy, and on uneven sections of pavement the front tire skips over bumps and threatens to fold if pushed too hard.

Cause:   The trouble is probably due to a combination of sag and ride height settings that leaves his bike riding high up front.

Solution:  Having a front tire skip over bumps on the exit of a turn is a sign that the fork is topping out–without enough sack to allow the suspension to sink into depressions in the road.

Check the bike’s front and rear sag settings to ensure correct spring preload. With the preload set, take the bike for a spin to determine if there’s any change in its behavior. If the problems persist, backing off the front preload will drop the front of the bike a bit, quickening the steering and letting the wheel track over bumps more effectively. If, however, the fork starts to bottom under braking with the preload backed off, the fork tubes can be raised in the triple clamps to sharpen the steering while keeping the original preload setting.

Adjustment	Setting	Effect
F o r k
Fork Oil Level	Oil level too low	Forks bottom out during hard braking or large bumps
	Oil level too high	Front wheel skips on bumps
Compression Damping	Too much	Bike difficult to turn in and will steer wide through the turn Front wheel skips on bumps Forks judder when braking in a straight Front end feels harsh on small bumps
	Not enough	Forks dive too quickly, possibly bottoming out Rear end wants to come around during hard braking Front end has a mushy and semi-vague feeling, similar to lack of rebound damping
Rebound Damping	Too much	Front end chatters coming out of corners Forks pack down on fast bumpy pavement Front end wiggles or tank-slaps on hard acceleration out of bumpy corners Harsh ride due to forks packing down
	Not enough	Excessive pogo action through chicanes Front end shakes (not chatters) in corners Front end shoots up too fast after braking Feels plush when riding straight, but mushy in corners and traction feel is poor When flicking into a corner at speed, the bike will porpoise or wallow a bit before settling down
Ride Height	Too low	Lack of high speed stability Easy turn-in into corners
	Too high	Sluggish or high effort turn-in into corners
Spring Rate	Too soft	Forks compress too much on smooth turns Forks bottom out during hard braking or large bumps Creates oversteer Can cause front to tuck under Turns easily into corners
	Too stiff	Creates understeer Lose front end on corner entry Harsh in corners Front end chatters coming out of corners Bike difficult to turn in Feels good under braking Front wheel skips on bumps
Rear Shock
Compression Damping	Too much	Shock rigid and harsh, but not as bad as too much rebound damping Rearwheel skips when braking on rippled pavement Very little rear end squat on acceleration
	Not enough	Shock bottoms out on medium sized bumps Rear end squats on acceleration Possible bottoming of shock Bike steers wide exiting corners (rear-low, nose-high)
Rebound Damping	Too much	Rear wheel hops on turns with small bumps, especially washboard Wheel skips when braking on rippled pavement Rear end packs down over series of bumps Rear feels harsh Bike steers wide exiting corners (rear-low, nose-high)
	Not enough	Too much kicking up when braking hard Bike wallows when exiting corners or in long rolling dips in sweepers Rear wheel chatters under hard acceleration over bumps Too much chassis pitch/pogo stick action
Ride Height	Too low	Motorcycle understeers on exit corners Difficult to change direction Poor grip from front tire on exit corners
	Too high	Lack of high speed stability Poor grip from rear tire Unstable under heavy braking
Spring Rate	Too soft	Ride is soft Rear end squats on acceleration “Light” feeling on the front
	Too stiff	Easy turn-in to corners Ride is harsh Poor rear wheel traction

DEFINITIONS    

Bottoming (also called bottoming out)–when a suspension component reaches the end of its travel under compression. Bottoming is the opposite of topping out. Cartridge Fork–a sophisticated type of fork that forces oil through bending shims mounted to the face of damping pistons contained within the fork body. The primary advantage of cartridge forks is they are less progressive than damping rod forks. The shims allow damping control at very low suspension speeds while high speeds deflect the shims more–causing less high-speed damping than fixed orifice damping rods. The resulting ride is firmer with less dive under braking while simultaneously lessening the amount of force square-edged bumps transfer to the chassis.

Damping General  is viscous friction. It is caused when liquids are forced through some type of restriction. The key thing to remember about damping is that it is dependent on fluid movement. This means a shock creates no damping force unless there’s movement-movement of the damper unit in compression or rebound as opposed to bike movement. Damping cares about vertical wheel velocity, not bike speed.

Compression Damping–controls the initial bump stroke” of the suspension. As the wheel is forced upward by the bump, the compression circuit controls the speed at which the suspension compresses, helping to keep the spring from allowing an excessive amount of travel or bottoming of the suspension. Damping–viscous friction caused by forcing a fluid through some type of restriction. Damping force is determined by the speed of the fluid movement, not the distance of suspension travel. This is DAMPENING

Damping Rod Fork–a simple type of fork that utilizes a tube with holes in it to create compression and rebound damping, delivering an extremely progressive damping curve. The faster the wheel moves vertically, the more oil that is shoved through the holes. Typically, damping rod forks have very little low-speed damping and a great deal of high-speed damping. The ride is characterized by excessive fork dive under braking and hydraulic lock when encountering square-edged bumps. Any change to the damping rod system, such as changing the size of the holes or altering the oil viscosity, affects the entire speed range.

High-Speed Damping–damping to control fast vertical movements of suspension components caused by road characteristics such as square-edged bumps. High-Speed damping is independent of motorcycle speed.

Low-Speed Damping–damping to control slow vertical suspension movements such as those caused by ripples in pavement. (This is also independent of motorcycle speed.)

Rebound Damping–controls the extension of the fork or shock after it compresses over a bump–hence the term rebound.

Fork Oil Level–the level of oil within the fork as measured when fully compressed without the spring installed. It is used in tuning the amount of air contained inside the fork. Since compressing air makes it act as a spring, raising the oil level leaves less room for air, resulting in a rising rate throughout the fork’s travel. Reducing the oil level reduces the force at the bottom, giving a more linear rate.

Free Sag–the amount the bike settles under its own weight. Both street bikes and race bikes require 0 to 5mm of free sag on the rear. The bike should not top out hard.

Packing–a phenomenon caused by excessive rebound damping. When a series of bumps, such as ripples, are encountered the suspension does not rebound completely between bumps and compresses (packs) further down on each successive bump. This can drastically change steering geometry if packing occurs on only one end of the motorcycle.

Preload–the distance a spring is compressed from its free length as it’s installed with the suspension fully extended. Preload Adjuster–a method of adjusting suspension components’ preload externally. These can be ramped or threaded.

Preload Spacer–material used to adjust a fork’s preload internally. Typically, thin-walled aluminum or PVC tubing is used.

Rake–the steering neck angle (not the fork angle) relative to vertical, which varies with changes in ride height. For example, the rake angle decreases when the front end compresses or is lowered. Changes in tire diameter can also influence rake by altering the ride height.

Ride Height–suspension adjustments (raising or lowering the fork or lengthening or shortening the shock) to alter the chassis attitude of the motorcycle.

Shock preload can be altered with a spanner wrench or with the time honored hammer and punch.

Sag–the amount the front or rear of the bike compresses between fully topped out and fully loaded with a rider (and all of his riding gear) on board in the riding position. Sag can also affect steering geometry. Extra sag on the front end will decrease the effective steering head angle, quickening steering, while too little front sag will slow steering. However, too much front sag combined with too little rear sag could make the bike unstable. How to set your sag

Spring–a mechanical device, usually in the form of a coil, that stores energy. When compressed, more energy is stored. Springs are position sensitive, caring only how much they have been compressed, not how quickly (as with damping).

Suspension Fluid–used inside a shock absorber to create damping when forced through orifices or valving. The fluid is also used for lubrication and should be in-compressible.

Topping Out–occurs when the suspension extends to its limit. A shock with a spring of the proper rate mounted should have just enough force to top out without a rider on board.

Trail–the horizontal distance between the front end’s point of rotation (i.e. where a line drawn through the steering head would intersect the ground) and the contact patch of the tire. Since trail is dependent on rake, it is a variable dimension that changes proportionally with the variation of rake during suspension action. For example, trail drops off dramatically when the bike reaches full dive under braking, giving a rider more leverage to initiate steering inputs.

Triple Clamp Offset–the distance from the center of the fork tubes to the steering stem center. The greater the offset, the smaller the trail dimension.

Unsprung Weight–the weight of every part of the motorcycle that is between the road and suspension (i.e. wheels, brakes, suspension components below the springs, etc.).

Valving–the mechanical hardware that creates damping. Valving is a combination of check valves, holes, ports, shims, springs, etc.

 

So, we hope that this comprehensive setup guideline will help you in the long run. Get busy with it and find a solid base to go from. It’s fun to make experiments and it gives you a drive/focus to your riding at the same time. We’d love to see you in our Suspension Workshop & Track Time class you could join to learn all about setting up motorcycles.

Superbike-Coach Corp