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.
At DVO, we pride ourselves on having some of the most adjustable and tunable products in the market. Although having all that adjustability is awesome, it can be confusing and difficult. Hopefully these tips will help you out to get your suspension performing perfectly for you! Below is a base tune chart, start with this if you want a quick set up to get you rollin. Remember, these are starting-points. Rider ability, preference and track conditions will vary. If you are a more advanced rider looking to achieve precise results, jump down to the “Bracketing” section.
When setting up your suspension, start from Wide-Open. Wide-Open is characterized by taking the adjuster and turning it counter-clockwise until it stops. Turn each adjuster to the Wide-Open setting before starting your base tune. Each adjustment below refers to making adjustments clockwise from the Wide-Open setting
Air Pressure Range: 60-100psi
OTT Range: 6 clicks = 1 full rotation. 15 full rotations total.
Rebound Range: 40 clicks total
High Speed Compression (HSC) Range: 33 clicks total
Low Speed Compression (LSC) Range: 27 clicks total
Rider Weight | Air Pressure | OTT | Rebound | HSC | LSC |
---|---|---|---|---|---|
120-139lbs | 54-63kg | 60-65psi | 0-2 rotations | 3-7 clicks | 0-1 clicks | 0-1 clicks |
140-159lbs | 64-72kg | 65-70psi | 3-4 rotations | 5-8 clicks | 0-2 clicks | 0-2 clicks |
160-179lbs | 73-81kg | 70-75psi | 5-6 rotations | 6-10 clicks | 2-3 clicks | 2-3 clicks |
180-199lbs | 82-90kg | 75-80psi | 6-7 rotations | 7-11 clicks | 2-4 clicks | 2-4 clicks |
200-219lbs | 91-100kg | 85-90psi | 8-10 rotations | 8-12 clicks | 3-5 clicks | 3-5 clicks |
220+lbs | 100+kg | 95-100psi | 11-14 rotations | 10-14 clicks | 5-7 clicks | 5-7 clicks |
Bracketing
Bracketing is a style of tuning that is for a more precise result. This is for an advanced rider looking to tune their products perfectly. It can be easy to get lost in your settings so our recommendation is to work with one adjustment feature at a time. Everybody has their own style of tuning and development but something that has seemed to work well for us is something called bracketing. Bracketing is going from one extreme to the other and finding the happy-medium between the two. For example, say you’re at your local track and you want to dial in your rebound. Start with the rebound adjuster completely open (counter-clockwise) and drop in to your run. Obviously this isn’t going to feel great for most people but that’s the point. Now you know what too much rebound feels like. Stop a couple sections into your trail and start to go in on rebound clicks (clockwise). We like to recommend three click increments and repeat this process until you feel the suspension is performing well. Once you have your rebound set, repeat the same steps with all the rest of your features, high and low speed compression, OTT, and rebound.
OTT (Explained)
Most suspension forks use a negative spring to control how the fork feels at the beginning of the stroke, most of them feel pretty good but there are some downfalls to this. You probably have noticed, but the spring rates on your rear shock and fork probably differ from the spring rates on your friends suspension right? That’s because weight and riding style differs from person to person. The same thing goes for negative springs. In the past, you had to open up the fork and change the negative spring to work just for you. Plain and simple, that’s a hassle. We decided to eliminate that problem and create an external adjustment that allows you to preload the negative spring. What does that do for you? That allows you to adjust how the beginning of the stroke to feel however you want it to. Light riders who run lower air pressure, can back the OTT out (counter clockwise) to hold the fork up in the beginning of the stroke. Heavier riders who run higher pressures can go in on OTT (clockwise) to keep the buttery smooth feel and awesome small bump sensitivity.
OTT Tuning
Tuning your OTT can seem a little bit intimidating after all that “technical jargon” but it’s easy so don’t worry! Just like your other adjustments, tune the OTT with the bracketing technique. To make the tuning process easier, start with the maximum amount of adjustment depending on your weight. (don’t worry I’ll explain) If you’re a lighter rider (100-160lbs.) start with no OTT (counter clockwise) and increase by 1 rotation (15 clicks per rotation) until you find the optimal feeling. If you’re a heavier rider (165lbs.+) start with the maximum amount of OTT (15 rotation clockwise) and back it out 1 rotation at a time until you find the optimal feeling. Once you know how the “extreme” feels, you can now dial your adjuster in and get your suspension dialed!
We understand that not every rider will fit into our standard base settings. Some riders may need a custom tuned bottom loader to get the perfect set up. Custom Loader’s are available if you are having a hard time finding that perfect tune for your Emerald. The loader can be removed and installed without losing a drop of oil. This makes tuning a breeze.
When do you need custom tuning?
If you are considering a custom tuned loader, please call or email us at support@dvosuspension.com to find out more information.
For general set-up on compression watch this quick video!
Setting up your fork is one of the most important things you can do to get the most out of your suspension. Follow these base tunes and get your suspension dialed. Remember, these are starting-points. Rider ability, preference and track conditions will vary.
When setting up your suspension, start from Wide-Open. Wide-Open is characterized by taking the adjuster and turning it counter-clockwise until it stops. Turn each adjuster to the Wide-Open setting before starting your base tune. Each adjustment below refers to making adjustments clockwise from the Wide-Open setting
Air Pressure Range: 60-100psi
OTT Range: 6 clicks = 1 full rotation. 15 full rotations total.
Rebound Range: 40 clicks total
High Speed Compression (HSC) Range: 33 clicks total
Low Speed Compression (LSC) Range: 27 clicks total
Rider Weight | Air Pressure | OTT | Rebound | HSC | LSC |
---|---|---|---|---|---|
120-139lbs | 54-63kg | 60-65psi | 0-2 rotations | 3-7 clicks | 0-1 clicks | 0-1 clicks |
140-159lbs | 64-72kg | 65-70psi | 3-4 rotations | 5-8 clicks | 0-2 clicks | 0-2 clicks |
160-179lbs | 73-81kg | 70-75psi | 5-6 rotations | 6-10 clicks | 2-3 clicks | 2-3 clicks |
180-199lbs | 82-90kg | 75-80psi | 6-7 rotations | 7-11 clicks | 2-4 clicks | 2-4 clicks |
200-219lbs | 91-100kg | 85-90psi | 8-10 rotations | 8-12 clicks | 3-5 clicks | 3-5 clicks |
220+lbs | 100+kg | 95-100psi | 11-14 rotations | 10-14 clicks | 5-7 clicks | 5-7 clicks |
Hardpack conditions
As the name suggests, hardpack dirt refers to riding conditions where the ground is hard. Hardpack is the most common soil condition if the weather has been dry, and the trail is in good condition without much loose dirt on top. Hardpack conditions may allow you to carry more speed with higher frequency bumps compared to loamy or muddy conditions.
Below are some recommendations while riding in hardpack conditins.
Loamy and Muddy conditions
In Loamy and Muddy conditions allow your tires to actually dig in. Loamy conditions mean the dirt is very loose and is more than just some loose dirt above hard pack. Mud as the name suggests, is wet, sloppy, and a whole lot of fun to ride in. Loamy and Muddy conditions absorb more energy because the dirt is going to give.
Below are some recommendations while riding in Loamy and Muddy conditions.
Troubleshooting your fork can sometimes be a bit tricky because you need to understand when to make what adjustments. One symptom may have two different solutions. Knowing which solution to use can sometimes be a guessing game. To take the guess work out of the equation use our Base Tune settings to make sure you have a solid starting point. Once you have set up your fork with the recommended Base Tune then you can continue with our troubleshooting guide. Please keep in mind that our Base Tune settings is only a starting point and adjustments can be made according to terrain and personal preference.
Symptoms |
Causes & Solutions |
Harsh Feeling Not Using Full Travel Poor Traction |
Causes: Too much compression damping or too high of a spring rate. Solution: Reduce the amount of compression damping on the adjuster, or go with a softer spring rate. |
Bottoming Out Soft Feeling |
Causes: Spring rate is too low or not enough compression damping. Solutions: increase spring rate or compression damping on the clickers. |
Too Much Sag Too Soft Initially |
Cause: Too little preload Solutions: Increase spring preload |
Harsh On Small Impacts, Still Using Full Travel | Cause: Too much preload or compression damping. Solution: Lower spring rate; decrease compression damping; reduce preload |
Suspension Progressively Feeling Harsher Over a Series of Bumps | Cause: Too much rebound damping Solution: Decrease amount of rebound with the clickers |
Ride Is Harsh, Rear End Kicks Up With Medium to Large Sized Hits |
Cause: Too much compression damping Solution: Reduce compression damping or decrease spring rate. |
Wheel Chatters Over Small Bumps Or On Downhills | Cause: Too much preload or Compression Damping Solution: Decrease Compression Damping and Reduce the amount of preload |
Front End Springs Back Poor Traction in Turns |
Cause: Not Enough Rebound Damping Solution: Increase Rebound Damping |
Headshake (Bars moving from side to side and rear end kicking up) |
Cause: Too little Compression Damping Or too soft of a spring rate. Solution: Increase compression damping or spring rate. If rear end is kicking up- lower SAG; reduce spring rate; decrease compression damping |
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 |
![]() 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 |
Below is a link to the full service/bleed guide for the Jade X Coil Shock.
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]
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 |
![]() 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 |
Below is a link to the full service/bleed guide for the Jade X Coil Shock.
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]