Topaz

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This is the Tuning page for the Topaz T3Air.

To access the Service page click HERE

To access the Set Up page click HERE 

To access the OWNER’S MANUAL click HERE

Topaz Features
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Below is a quick list of features on the Topaz. Every one of these features can aid in your tuning experience. Familiarize yourself with these features as we will be breaking them down and teaching you about each one.

 

-Air Pressure/Spring
-9 Clicks of Dynamic Rebound via Piston & Shims (internally tunable if needed)
-3 Position Dynamic Compression via easy access lever
-Bladder pressure can be adjusted from 170psi (lighter rider) to 200psi (heavier rider)
-Air Canister volume reducers can be used to reduce internal air volume. Optional Air Canisters will be available to offer further fine tuning of the air spring.

 

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Air Volume Tuning
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WHAT IS AIR VOLUME TUNING?

In air shocks, the air takes the place of traditional coil springs. It works the same way by compressing the air to create a spring. Air volume is the amount of space available to fill with air and therefore determines the type of spring curve. Air volume tuning is changing the amount of volume to make the shock more progressive or linear.

WHAT’S THE DIFFERENCE BETWEEN PROGRESSIVE AND LINEAR?

These two terms are thrown around in mtb suspension lingo often but many people don’t truly understand the difference. Knowing and understanding the difference can drastically improve your feel of suspension and aid in tuning to fit your personal riding style.

Spring curves refer to the amount of force it takes to compress the spring at a given point in the travel. The amount of force it takes to continue to compress the spring determines if it is a linear or progressive spring curve.

Progressive spring curves take a variable amount of force to compress a shock throughout the entire stroke. That means it takes more force to compress the spring at the end of the travel than at the beginning. Progressive spring rates take very little force to initiate suspension movement then a high amount of force to fully compress or bottom out. This type of spring curve gives the rider great small bump compliancy and excellent bottom out resistance.

Linear spring curves take a very consistent amount of force to compress a shock throughout the entire stroke. For example, if we have a 300lb spring that is 12 inches long, it takes 300lbs to compress the spring 1 inch. The next inch of spring compression will take another 300lbs and so on until the spring becomes solid.

HOW DO I TUNE THE AIR VOLUME?

The DVO Topaz allows you to tune the volume in both the positive and negative side of the air canister. This is done with the provided air volume bands that come with your DVO Topaz. The tuning bands can be installed in the air shock in a matter of minutes without having to remove the shock from the bike. Watch the tutorial below to insure you tune your volume properly.

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Understanding the Bladder
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The next step in the setup of your Topaz Air shock is understanding the bladder. We have implicated the use of a bladder in all of our rear shocks for increased performance in many aspects. Bladders have been widely used in motocross shocks for years but haven’t been seen too often in mtb shocks. Why is that? Bladders can be costly on the production side and take skilled technicians to properly bleed and install. On mass-produced suspension products that isn’t something they’re willing to invest in. At DVO we take pride in making high performance products and cutting corners in production at the cost of performance isn’t what we’re about.

WHY USE A BLADDER?

Bladders are located in the reservoir of the rear shock and take the place of a traditional IFP or internal floating piston. They both have the same purpose but completely different ways of executing it. That purpose is to seperate the air from the oil. A bladder is basically a ballon which is filled with air and seated to the end cap. The bladder is filled with a high PSI to push back against the oil which creates pressure in the system. As the shock is compressed, oil flows through the the system and starts to compress the bladder.

When the shock goes to extend again, the bladder pushes the oil back in the opposite direction. This decreases the chances of what’s called cavitation. Cavitation is when there is a gap in the oil caused from air bubbles and creates a temporary loss of damping. Here’s an example of cavitation. Picture turning on a hose, what happens as the water is pushing the air out of the line? Water intermittently shoots out in between gaps of air. This same situation happens in suspension causing a loss of damping.

The real benefit of using a bladder over an IFP is when the shock is working dynamically or in “riding situations”. As the shock is compressing and rebounding at a high velocity, it can sometimes have a difficult time changing directions. An IFP usually has a moment of hesitation in that situation due to stiction between the outer O-ring and the inside surface of the reservoir. With a bladder that can’t happen and you get unmatched small bump sensitivity with a seamless transition from compression to rebound.

CAN I ADJUST THE PRESSURE OF THE BLADDER ON MY SHOCK?

Absolutely. Changing the bladder pressure is easy and something you should check consistently. Just unscrew the air cap at the end of the reservoir and use a shock pump to adjust or check the pressure. When checking the pressure, the initial reading from the pump will be low. This is because air needs to fill the hose of the pump before the PSI can be determined.

HOW WILL THE PRESSURE AFFECT THE PERFORMANCE?

The pressure within the bladder will have a drastic affect on performance. As we talked about before, the higher the pressure the less chance you have of cavitation. The pressure range of the bladder is 170-200PSI. The bladder pressure also has an effect on the entire stroke of the shock. The higher the bladder pressure the firmer the shock will be. The lower the pressure, the softer. Lighter riders can run a lower bladder pressure and heavier riders should ride a higher pressure.

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SAG as a Tuning Feature
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SAG can actually be a key tuning feature that’s crucial to the handling of your bike and the position of your body while riding. Having a good understanding of SAG is extremely important. It will be the first thing you check after evey adjustment you make.

WHAT IS SAG?

SAG is the amount the shock compresses under your own body weight. Make sure you check your SAG with all your riding gear on (riding shoes, hydration pack, etc). The ideal amount of SAG is best determined by your bike manufacturer, there are many linkage designs & each design works best according their design.

WHY IS IT SO IMPORTANT?

Insuring that your shock has the correct amount of SAG is crucial to the set up and performance of your air shock. This is the easiest and best way to determine your shock is working in the most effective range for your rider weight.

HOW DOES THE SAG AFFECT PERFORMANCE?

Since SAG is the amount the shock compresses under your body weight, it allows the shock to be pre-compressed while riding. When riding on a flat surface and a hole is encountered, it allows the shock to fall into the hole and absorb the up-face with the entire stroke of the shock. Having the correct amount of SAG allows the bike to track the ground and keep the feedback to the rider at a minimum.

CAN SAG AFFECT PEDALING?
SAG will determine the amount of squat your bike has. The less SAG you have, the pedal bob will be reduced but small bump compliancy will be negatively affected. The more SAG you have, the small bump compliancy will be increased but pedaling efficiency will decrease. It’s beneficial to run less sag on hard packed pedaling trails since carrying momentum and pedaling is the priority. On rougher trails, more SAG actually carries more momentum by allowing the wheel to move over bumps rather than be hung up by them.

HOW DOES SAG EFFECT THE HANDLING OF MY BIKE?

It is very beneficial to test different SAG settings for various riding conditions. Increasing the amount of SAG on your bike drastically increases high speed stability but decreases front end traction and cornering ability. Increase your SAG on high speed or sandy tracks to improve stability. Too much SAG will cause your front end to be too light and deflect over bumps.

DOES SAG EFFECT MY BODY POSITION ON THE BIKE?

SAG definitely has a big affect on your body position. The more SAG you have the more your bike will squat while riding. This positions your center of gravity behind the seat which improves high speed stability but decreases front end traction. Riders can then compensate for this by moving their body weight forward while cornerning. This set up is great for steep/rough trails where pedaling isn’t as much of a priority.

Reducing SAG will create a “stink bug” effect and bring your body weight forward. This drastically improves cornering ability but decreases high speed stability. Riders can compensate for that by moving their body weight back in high speed sections of trail. This set up is great for hard-packed single track or trails with tight turns and pedaling.

Click HERE to learn how to set you SAG.

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Owner’s Manual
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Choose Language: 

English | French | German | Italian | Spanish | Japanese

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Diamond Tuning
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This is the Tuning page for the Diamond.

To access the DIAMOND BOOST TRAVEL CHANGE GUIDE  click HERE

To access the DIAMOND NON BOOST TRAVEL CHANGE GUIDE  click HERE

To access the OWNER’S MANUALS click HERE

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Topaz
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This is the Tuning page for the Topaz T3Air.

To access the Service page click HERE

To access the Set Up page click HERE 

To access the OWNER’S MANUAL click HERE

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Emerald
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This is the Set Up page for the Emerald.

To access the Tuning page click HERE

To access the Service Guides click HERE

To access the Owner’s Manuals click HERE

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Diamond
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This is the Set Up page for the Diamond.

To access the DIAMOND BOOST TRAVEL CHANGE GUIDE  click HERE

To access the DIAMOND NON BOOST TRAVEL CHANGE GUIDE  click HERE

To access the OWNER’S MANUALS click HERE

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Garnet Seat Post
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Topaz
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This is the Set Up page for the Topaz T3Air.

To access the TUNING page click HERE

To access the Service page click HERE

To access the OWNER’S MANUAL click HERE

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Topaz
Don't be greedy. Share!Share on FacebookShare on Google+Tweet about this on TwitterEmail this to someone
This is the Service page for the Topaz T3Air.

To access the TUNING page click HERE

To access the Set Up page click HERE

To access the OWNER’S MANUAL click HERE

We recommend all DVO Suspension service should be performed by a qualified bicycle mechanic. Terrain, location and riding ability can greatly affect the interval in which maintenance should be performed. Always inspect your products, and lean towards caution if maintenance is in question. When in doubt, consult a qualified bicycle mechanic, or contact DVO Suspension directly.[/box]

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Air Pressure
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Setting the air pressure in the DVO Diamond is setting the spring rate for your fork. This is what is going to make the fork firmer or softer. Below is a base setting chart for air pressure to get you started. Set your pressure to the recommended PSI then check your SAG point. If you are sagging too much, add some air pressure, if you’re sagging too little, remove air pressure.

Proper Set Up

The Diamond uses an external negative spring adjust (OTT) to tune the beginning of the travel  (sensitivity of the fork). Once you get into the mid-stroke of the fork, the air spring (air pressure) is active. This controls your mid-stroke support and your bottom out. In simpler terms, set your air pressure for your mid-stroke and bottom out then set your OTT to fine tune how it feels off the top.

How do I know how much OTT is right for my air pressure? 

Lighter riders (lower air pressure) will use less OTT. (less sensitive) Heavier riders will need more OTT (more sensitive). The reason for this is because the OTT is there to counter-act the forces of a higher air pressure so you don’t loose small bump sensitivity. When you are using a lower air pressure, you don’t need as much to counter-act the air pressure. If you run too much OTT with a light air pressure, the fork will suck itself down and you will loose travel.

View one of the lower tabs to learn more about your OTT

To access the air valve you must remove the air spring cap.  Attach your shock pump securely and inflate the air spring to the recommended air pressure. After you have added the proper amount of air pressure remember to securely replace the air spring cap so that no dirt or moisture can get inside.

Access air valve by removing air cap

Access air valve by removing air cap

Attach shock pump to air valve and inflate to recommended pressure or proper sag is achieved

Attach shock pump to air valve and inflate to recommended pressure or proper sag is achieved

Air Pressure Range: 90-170psi

Rider Weight Air Pressure
120-139lbs | 54-63kg 90-100psi
140-159lbs | 64-72kg 100-110psi
160-179lbs | 73-81kg 110-125psi
180-199lbs | 82-90kg 125-130psi
200-219lbs | 91-100kg 130-135psi
220-239lbs | 100-108kg 135-140psi
240+lbs | 109kg+ 140-170psi

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Suspension Terms & Definitions
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Base Valve
Bottoming Out
Closed Cartridge Dampers
Compression Damping
Fork Oil Level
Free Sag
High-Speed Damping
Low-Speed Damping
Mid-Valve
Negative Spring
Open Bath Dampers
Packing
Platform Damping
Rebound Damping
Spring Preload
Spring Type
Stiction
Twin Tube Dampers
Valving


Base Valve
Base valves are located at the base of the fork leg or on the shock’s reservoir  and generally function to control high speed compression. Base valves or “BV” are fixed & the piston that is attached to a shaft is referred to as the mid-valve or “MV”. Both forks and shocks can have a “BV” and a “MV”.

Bottoming Out
When your suspension reaches the end of its travel on an impact. You generally want to reach full bottom on occasion but NOT all the time. Continual bottoming can wreak havoc on the suspension system leading to breakage.

Closed Cartridge Dampers
Closed Cartridge Dampers are the opposite of an Open Bath Damper, in a closed system the oil solely contained within a cartridge tube and does not flow into the fork leg. Therefore, additional oil or lubricant is added to the inside of the leg to lubricate the seals and bushings.

Compression Damping
This is what gives your bike it’s feeling of plushness, or stiffness. Compression determines how fast the suspension can compress when hitting a bump. If your suspension is too “stiff”, the system won’t compress fast enough to absorb a bump force. When there is not enough damping, the bike has soft, mushy feeling to it and will compress through its travel with little damping resistance.

Fork Oil Level
The level of oil inside the fork. It’s typically measured in cc’s by fully compressing the fork without the spring installed. It is used in tuning the amount of air contained inside the fork. Since compressing air acts like a spring, raising the oil level leaves less room for air, resulting in a rising rate throughout the fork’s travel.

Free Sag
The amount the bike settles under its own weight without the rider. With mountain bikes becoming lighter and lighter, free sag is really not a critical tuning element but still worth mentioning.

High-Speed Damping
Damping feature that controls fast suspension movements. High-speed damping comes into effect on fast, rough, technical trails, g-outs, hard landings. HSD refers to the shaft speed of the suspension and not the actual riding speed. HSD is controlled through a high speed oil circuit best located in the base valve.

Low-Speed Damping
Damping feature to control slower vertical movements such as climbing or slower paced trails and bumpy whoop sections. A good example of low speed is rolling slowly over a large rock and riding to its downside, this is where the suspension will fully compress but at a slower rate and low speed compression circuit comes into play.  LSD refers to the shaft speed of the suspension and not the actual riding speed. LS damping is best controlled through a low speed oil circuit and or shim stack.

Mid-Valve
Mid valves are located on the piston shaft and function in the middle part of the stroke. Mid valves can play an important function in keeping a long travel fork from diving too far into its travel. Mid valves “”MV” function when oil passes through the “MV” from one side of the chamber to the other. The rebound valve is also located on the “MV”.

Negative Spring
A negative spring functions to control the return of the suspension when it reaches full extension. Negative springs can be air, coil spring, rubber bumper or a combination of both. A negative spring also functions to soften the “top out feel” when the wheel/suspension rapidly extends and it also helps initiate compression providing a smoother or more sensitive initial feel. An adjustable negative spring offers the greatest tuning range for riders weight, for example a heavy rider will need a higher or stiffer spring to resist pre-compression, but the high spring rate may also completely compress the negative spring rendering it ineffective to control top out.

Open Bath Dampers
Open Bath refers to a cartridge that is NOT closed and allows oil to flow from the inside of the damper to the outside of the cartridge or inside of the fork legs. Open Bath Dampers use oil for damping, lubrication, cooling, and end stroke “ramp up” or “progression”.  But the downside of all this oil is the added weight of all the excess oil that is used to fill the entire fork leg.

Packing
An issue caused from too much rebound damping. When a series of bumps are encountered, the suspension doesn’t rebound fast enough to absorb the next bump. The suspension keeps compressing more and more after each bump and it gives the rider a very harsh feeling and even loss of traction and control because the wheels no longer follows the contour of the terrain.

Platform Damping
A platform is generally referred to as resistance to initial suspension compression usually generated by pedaling or rider induced forces. A platform can be achieved by various methods and usually the best way to limit suspension “bobbing” is to restrict oil flow through the low speed circuit. Depending on what technology you have and there are various designs out there, choking off the low speed circuit can be achieved by either adjusting a pressure spring on the shim stack, adjusting the depth of a bleed needle or changing the size of an orifice via a slide. These are just a few of the most common methods to deliver platform damping feel to improve pedaling efficiency.

Rebound Damping
Once your suspension has hit a bump and compresses, now its time for your rebound damping to kick in. Rebound controls how fast the fork extends back from compression to keep the wheel on the ground. Rebound can affect your traction as well. Too much rebound damping will keep the suspension compressed when it should be extending to stay on the ground on the downside of a bump, and the wheel will loose contact with the ground. This is called “Packing”. Too little rebound damping will cause the suspension to “bounce” and “hop” also causing a loss of traction and control. Proper rebound control is equally important as compression and it is very important to properly tune this performance feature. The rebound valve is best located on the “MV” with a tapered shim stack controlling oil flow. Damping systems that use oriface or small holes to control damping simply cannot control the dynamics of high performance suspension.

Spring Preload
The preload ring or collar compresses the shock or fork spring and either shortens or extends the spring to its original length. Preload is used to adjust the suspension to the correct range of operation within the suspension’s travel- more spring preload will the raise the bike up and less preload will lower it.

Spring Type
Springs can either be coil or air and both are widely used in mountain bike suspension systems. Springs work to resist pre-compression of the suspension under the riders weight and is independent of the compression system which refers to damping. Too stiff of a spring rate delivers a harsh and uncontrolled feel, if your spring rate is too soft, the suspension will sit too far into its travel and will feel mushy and easily bottom out . Its important to have the correct spring rate for each rider and setting up “SAG” will determine whether you have the correct rate or not.

Stiction
Or static friction, is a term that describes friction that occurs from parts rubbing or gliding across one another. For example, on both the rebound and compression stroke, the stanchion tubes must glide against the bushings, o-rings, seals, and other parts. The parts that come in contact with one another create friction and when a bending load is applied the stiction can increase causing the suspension to bind and feel notchy. Stiction can also dramatically increase after seals become dry resulting in the loss of small bump sensitivity.

Twin Tube Dampers
Twin Tube systems generally combine the technology of an “Open Bath” Damper and a “Closed Cartridge” system. With a Twin Tube design, the cartridge damper is inside of a tube (hence twin tube) allowing oil to flow from the cartridge damper into and from the twin tube providing additional oil flow and damping performance without the added weight of “excess” oil that is needed to fill the fork leg.

Valving
The mechanical hardware that creates compression or rebound damping. Valving is a combination of check valves, holes, ports, shims, springs, etc. The best valving arrises out of piston with a series of tapered shim stacks which are very thin high quality steel “washers” that when combined together produce a smooth yet linear flex pattern when oil flows around them. Shims provide the resistance to the oil flowing through the piston at various speeds.  The lower amount of shims used typically means the damping quality is less. Systems that use one or two shims deliver a harsh feel on high speed hits, unfortunately, many so-called high performance suspension designs use very few shims and/or only small holes to control damping forces. If your clickers are ineffective or have a very small range, this is due to improper piston & shim stack design.

 

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Owner’s Manual

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Choose Language: 

English | French | German | Italian | Spanish | Japanese

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Diamond Tuning

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This is the Tuning page for the Diamond.

To access the DIAMOND BOOST TRAVEL CHANGE GUIDE  click HERE

To access the DIAMOND NON BOOST TRAVEL CHANGE GUIDE  click HERE

To access the OWNER’S MANUALS click HERE

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Topaz

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This is the Tuning page for the Topaz T3Air.

To access the Service page click HERE

To access the Set Up page click HERE 

To access the OWNER’S MANUAL click HERE

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Emerald

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This is the Set Up page for the Emerald.

To access the Tuning page click HERE

To access the Service Guides click HERE

To access the Owner’s Manuals click HERE

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Diamond

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This is the Set Up page for the Diamond.

To access the DIAMOND BOOST TRAVEL CHANGE GUIDE  click HERE

To access the DIAMOND NON BOOST TRAVEL CHANGE GUIDE  click HERE

To access the OWNER’S MANUALS click HERE

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Garnet Seat Post

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Topaz

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This is the Set Up page for the Topaz T3Air.

To access the TUNING page click HERE

To access the Service page click HERE

To access the OWNER’S MANUAL click HERE

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Topaz

Don't be greedy. Share!Share on FacebookShare on Google+Tweet about this on TwitterEmail this to someone
This is the Service page for the Topaz T3Air.

To access the TUNING page click HERE

To access the Set Up page click HERE

To access the OWNER’S MANUAL click HERE

We recommend all DVO Suspension service should be performed by a qualified bicycle mechanic. Terrain, location and riding ability can greatly affect the interval in which maintenance should be performed. Always inspect your products, and lean towards caution if maintenance is in question. When in doubt, consult a qualified bicycle mechanic, or contact DVO Suspension directly.[/box]

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Air Pressure

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Setting the air pressure in the DVO Diamond is setting the spring rate for your fork. This is what is going to make the fork firmer or softer. Below is a base setting chart for air pressure to get you started. Set your pressure to the recommended PSI then check your SAG point. If you are sagging too much, add some air pressure, if you’re sagging too little, remove air pressure.

Proper Set Up

The Diamond uses an external negative spring adjust (OTT) to tune the beginning of the travel  (sensitivity of the fork). Once you get into the mid-stroke of the fork, the air spring (air pressure) is active. This controls your mid-stroke support and your bottom out. In simpler terms, set your air pressure for your mid-stroke and bottom out then set your OTT to fine tune how it feels off the top.

How do I know how much OTT is right for my air pressure? 

Lighter riders (lower air pressure) will use less OTT. (less sensitive) Heavier riders will need more OTT (more sensitive). The reason for this is because the OTT is there to counter-act the forces of a higher air pressure so you don’t loose small bump sensitivity. When you are using a lower air pressure, you don’t need as much to counter-act the air pressure. If you run too much OTT with a light air pressure, the fork will suck itself down and you will loose travel.

View one of the lower tabs to learn more about your OTT

To access the air valve you must remove the air spring cap.  Attach your shock pump securely and inflate the air spring to the recommended air pressure. After you have added the proper amount of air pressure remember to securely replace the air spring cap so that no dirt or moisture can get inside.

Access air valve by removing air cap

Access air valve by removing air cap

Attach shock pump to air valve and inflate to recommended pressure or proper sag is achieved

Attach shock pump to air valve and inflate to recommended pressure or proper sag is achieved

Air Pressure Range: 90-170psi

Rider Weight Air Pressure
120-139lbs | 54-63kg 90-100psi
140-159lbs | 64-72kg 100-110psi
160-179lbs | 73-81kg 110-125psi
180-199lbs | 82-90kg 125-130psi
200-219lbs | 91-100kg 130-135psi
220-239lbs | 100-108kg 135-140psi
240+lbs | 109kg+ 140-170psi

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Suspension Terms & Definitions

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Base Valve
Bottoming Out
Closed Cartridge Dampers
Compression Damping
Fork Oil Level
Free Sag
High-Speed Damping
Low-Speed Damping
Mid-Valve
Negative Spring
Open Bath Dampers
Packing
Platform Damping
Rebound Damping
Spring Preload
Spring Type
Stiction
Twin Tube Dampers
Valving


Base Valve
Base valves are located at the base of the fork leg or on the shock’s reservoir  and generally function to control high speed compression. Base valves or “BV” are fixed & the piston that is attached to a shaft is referred to as the mid-valve or “MV”. Both forks and shocks can have a “BV” and a “MV”.

Bottoming Out
When your suspension reaches the end of its travel on an impact. You generally want to reach full bottom on occasion but NOT all the time. Continual bottoming can wreak havoc on the suspension system leading to breakage.

Closed Cartridge Dampers
Closed Cartridge Dampers are the opposite of an Open Bath Damper, in a closed system the oil solely contained within a cartridge tube and does not flow into the fork leg. Therefore, additional oil or lubricant is added to the inside of the leg to lubricate the seals and bushings.

Compression Damping
This is what gives your bike it’s feeling of plushness, or stiffness. Compression determines how fast the suspension can compress when hitting a bump. If your suspension is too “stiff”, the system won’t compress fast enough to absorb a bump force. When there is not enough damping, the bike has soft, mushy feeling to it and will compress through its travel with little damping resistance.

Fork Oil Level
The level of oil inside the fork. It’s typically measured in cc’s by fully compressing the fork without the spring installed. It is used in tuning the amount of air contained inside the fork. Since compressing air acts like a spring, raising the oil level leaves less room for air, resulting in a rising rate throughout the fork’s travel.

Free Sag
The amount the bike settles under its own weight without the rider. With mountain bikes becoming lighter and lighter, free sag is really not a critical tuning element but still worth mentioning.

High-Speed Damping
Damping feature that controls fast suspension movements. High-speed damping comes into effect on fast, rough, technical trails, g-outs, hard landings. HSD refers to the shaft speed of the suspension and not the actual riding speed. HSD is controlled through a high speed oil circuit best located in the base valve.

Low-Speed Damping
Damping feature to control slower vertical movements such as climbing or slower paced trails and bumpy whoop sections. A good example of low speed is rolling slowly over a large rock and riding to its downside, this is where the suspension will fully compress but at a slower rate and low speed compression circuit comes into play.  LSD refers to the shaft speed of the suspension and not the actual riding speed. LS damping is best controlled through a low speed oil circuit and or shim stack.

Mid-Valve
Mid valves are located on the piston shaft and function in the middle part of the stroke. Mid valves can play an important function in keeping a long travel fork from diving too far into its travel. Mid valves “”MV” function when oil passes through the “MV” from one side of the chamber to the other. The rebound valve is also located on the “MV”.

Negative Spring
A negative spring functions to control the return of the suspension when it reaches full extension. Negative springs can be air, coil spring, rubber bumper or a combination of both. A negative spring also functions to soften the “top out feel” when the wheel/suspension rapidly extends and it also helps initiate compression providing a smoother or more sensitive initial feel. An adjustable negative spring offers the greatest tuning range for riders weight, for example a heavy rider will need a higher or stiffer spring to resist pre-compression, but the high spring rate may also completely compress the negative spring rendering it ineffective to control top out.

Open Bath Dampers
Open Bath refers to a cartridge that is NOT closed and allows oil to flow from the inside of the damper to the outside of the cartridge or inside of the fork legs. Open Bath Dampers use oil for damping, lubrication, cooling, and end stroke “ramp up” or “progression”.  But the downside of all this oil is the added weight of all the excess oil that is used to fill the entire fork leg.

Packing
An issue caused from too much rebound damping. When a series of bumps are encountered, the suspension doesn’t rebound fast enough to absorb the next bump. The suspension keeps compressing more and more after each bump and it gives the rider a very harsh feeling and even loss of traction and control because the wheels no longer follows the contour of the terrain.

Platform Damping
A platform is generally referred to as resistance to initial suspension compression usually generated by pedaling or rider induced forces. A platform can be achieved by various methods and usually the best way to limit suspension “bobbing” is to restrict oil flow through the low speed circuit. Depending on what technology you have and there are various designs out there, choking off the low speed circuit can be achieved by either adjusting a pressure spring on the shim stack, adjusting the depth of a bleed needle or changing the size of an orifice via a slide. These are just a few of the most common methods to deliver platform damping feel to improve pedaling efficiency.

Rebound Damping
Once your suspension has hit a bump and compresses, now its time for your rebound damping to kick in. Rebound controls how fast the fork extends back from compression to keep the wheel on the ground. Rebound can affect your traction as well. Too much rebound damping will keep the suspension compressed when it should be extending to stay on the ground on the downside of a bump, and the wheel will loose contact with the ground. This is called “Packing”. Too little rebound damping will cause the suspension to “bounce” and “hop” also causing a loss of traction and control. Proper rebound control is equally important as compression and it is very important to properly tune this performance feature. The rebound valve is best located on the “MV” with a tapered shim stack controlling oil flow. Damping systems that use oriface or small holes to control damping simply cannot control the dynamics of high performance suspension.

Spring Preload
The preload ring or collar compresses the shock or fork spring and either shortens or extends the spring to its original length. Preload is used to adjust the suspension to the correct range of operation within the suspension’s travel- more spring preload will the raise the bike up and less preload will lower it.

Spring Type
Springs can either be coil or air and both are widely used in mountain bike suspension systems. Springs work to resist pre-compression of the suspension under the riders weight and is independent of the compression system which refers to damping. Too stiff of a spring rate delivers a harsh and uncontrolled feel, if your spring rate is too soft, the suspension will sit too far into its travel and will feel mushy and easily bottom out . Its important to have the correct spring rate for each rider and setting up “SAG” will determine whether you have the correct rate or not.

Stiction
Or static friction, is a term that describes friction that occurs from parts rubbing or gliding across one another. For example, on both the rebound and compression stroke, the stanchion tubes must glide against the bushings, o-rings, seals, and other parts. The parts that come in contact with one another create friction and when a bending load is applied the stiction can increase causing the suspension to bind and feel notchy. Stiction can also dramatically increase after seals become dry resulting in the loss of small bump sensitivity.

Twin Tube Dampers
Twin Tube systems generally combine the technology of an “Open Bath” Damper and a “Closed Cartridge” system. With a Twin Tube design, the cartridge damper is inside of a tube (hence twin tube) allowing oil to flow from the cartridge damper into and from the twin tube providing additional oil flow and damping performance without the added weight of “excess” oil that is needed to fill the fork leg.

Valving
The mechanical hardware that creates compression or rebound damping. Valving is a combination of check valves, holes, ports, shims, springs, etc. The best valving arrises out of piston with a series of tapered shim stacks which are very thin high quality steel “washers” that when combined together produce a smooth yet linear flex pattern when oil flows around them. Shims provide the resistance to the oil flowing through the piston at various speeds.  The lower amount of shims used typically means the damping quality is less. Systems that use one or two shims deliver a harsh feel on high speed hits, unfortunately, many so-called high performance suspension designs use very few shims and/or only small holes to control damping forces. If your clickers are ineffective or have a very small range, this is due to improper piston & shim stack design.

 

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