Why do I need to equalize the pressure when airing up my shock?
When initially airing up your shock, you will need to equalize the positive & negative chambers. The air from the pump will flow into the positive chamber and you will need to compress the shock in order for the air to transfer to the negative chamber. This video will teach you the proper way to do this.
What do the positive and negative chambers do?
The negative chamber is responsible for counteracting the forces of the positive air pressure. This is your beginning stroke. The Positive pressure is your air spring. This controls your mid-stroke and bottom out. In the Topaz, the two chambers work together to create a seamless transition throughout the stroke.
The use of thin steel shims is critical to the feel of any high-end suspension system and especially with the new DVO products. Our forks and shocks will be finely tuned with a generous combination of shim stacks to provide that stable and predictable suspension feel for both compression and rebound. Shims are used to restrict oil flowing through the holes or ports in a piston. Shims are configured in various diameters and thickness to achieve specific results as a “shim stack”.
The larger diameter shim that sits on the piston surface is the first shim to resist oil flow and generally affects the low-speed compression. The shims that are in the middle and farthest away from the piston’s surface affects the mid-high speed compression feel. When proper shim stack settings are achieved the end result is a bottomless feel on compression and a controlled/predicable extension that works in concert to keep your wheels planted on the ground. The main reason shim stacks are so amazing is that they are dynamic or speed sensitive and a proper stack can deliver a wide range of damping performance purely based on velocity.
Many companies use orifice or small holes to control compression and or rebound in their dampers, especially on lower end products. There are serious limitations to orifice dampers, under low speeds oil can easily flow through a hole but when speeds increase, oil flow becomes restricted and hydraulic locking occurs. Thats where a harsh feel on compression occurs or an unpredictable hopping of the front wheel on the rebound stroke can occur reducing traction and control.
When it comes to comfort, traction, and ride stability, rebound can have a massive impact on it. Getting your rebound set right can be tricky sometimes so the best way to set it correctly is to actually understand what it’s doing.
So what exactly is rebound damping? Rebound damping refers to the movement of the suspension as it returns back to its relaxed position (after compression). As the shock or fork compresses andthe spring will store a certain amount of that energy. On the backside of the impact, that stored energy within the spring wants to release and push the tire down towards the ground in an uncontrolled way. Damping is changing that stored kinetic energy into heat. This is one of the reasons why your fork or shock heats up while you are riding.
How do changes in rebound affect performance?
The more rebound (slower rebound) damping you have , the more the flow of oil is being “choked”. Therefore the return speed of the wheel to the ground is decreased. The less rebound (faster rebound) damping you have, the oil flow is less restricted and therefore the return speed is increased.
Let’s take a look at a suspension set up with too little rebound (too fast) damping. As you decrease (speed up rebound) the amount of rebound damping, the comfort level will increase and the traction will decrease. When you encounter an impact while riding, the suspension will compress and the energy stored within the spring will want to release on the backside of the hit. Without the proper amount of rebound damping to control that energyrelease, thewheel will become unweighted and bounce. Resulting in a complete loss of traction.
Check out Mikey Sylvestri in this rough section running his fork a little on the fast side. When entering a section of trail with successive bumps or hits, it’s extremely important that the suspension rebounds evenly. As shown above, his front wheel is about 6 inches off the ground while the rear suspension is tracking the ground. When your bike is reacting to every bump evenly, you are in control.
Mikey Slowed his rebound down 3 clicks and now his bike is tracking the ground evenly. (as shown above)
When testing rebound settings, start from wide open (counter-clockwise) and go in (clockwise) with 3 click increments. Try and be aware of your bike staying evenly balanced over successive hits as you test. Once you find a setting you feel comfortable with write down your settings for future reference.
Check out the video below of Rocket Ronnie showing you how to properly set up sag on your bike. For detailed instructions read below the video. If there are any questions please let us! Contact us attech@dvosuspension.com
Why Set Sag? Setting the sag is extremely important when fine-tuning your bicycle just for you. Sag is basically a measurement of how much your suspension compresses when you are sitting on the bike. Setting the sag at 20-25% of the total amount of travel is prime for getting the most out of your fork or rear shock. When it is set up correctly, it ensures your suspension will the work the way it’s designed to, preferably in its “sweet spot”. If your suspension is too soft, you’ll be sitting too far in the travel & the fork or shock cant react properly to the next set of bumps. If your suspension is too stiff or over-sprung, your bike won’t have adequate traction and deliver an overall harsh feeling ride.
So, follow these quick and easy steps to set the sag on your suspension.
Step 1 – If your fork doesn’t have already have an o-ring on the stanchion, attach a zip tie (semi-snugly) around the stanchion tube of the fork. Make sure you move the zip tie to bottom of the leg, so it is touching the oil seal. Note: remove the zip tie after your sag is set, zip ties in conjunction with dirt & mud may scratch the stanchion surface.
Step 2 – Prop your bicycle against the wall or in rack (something to secure your bike) and sit on it. Sit on it how you would normally do in a riding position with your feet on the pedals. Bounce up and down on the suspension to allow the fork and shock to settle into place. Make sure you are wearing all gear you would normally ride in (helmet, shoes, camel back & water bottles full).
Step 3 – Get off your bike and measure the amount of space the zip tie has traveled up the leg. The measurement from the seal to the zip tie is what’s called your current sag. Then measure the total length of the fork. Make sure to write down your measurements in either millimeters or inches.
Step 4 – Time to do some math. You want your current sag measured in percentage, so A is going to be your current sag, and B will be the total length of the fork. To calculate, it’s: A/B x 100. (200mm of travel should relate to 40-50mm in sag)
Step 5 – If you’re lucky, your current sag will be at 20-25%. If not, you’re going to need to adjust the spring’s preload (air pressure or coil) depending on what type of spring system you’re using. If you have too little sag, you want to decrease the preload allowing the spring to compress more. If there is too much sag, you will want to increase the preload, which will reduce the sag amount.
NOTE: If you have a coil system (front or rear) don’t over-preload the spring, if you have more than 5mm of preload on a coil, you might need to bump up to the next available spring rate. When using an air system, increase your pressure by 3-5 psi increments until your sag amount is 20-25%. After setting up your sag, you will also need to readjust your rebound damping. Rebound controls the return rate of your suspension, increasing the preload or spring rate will require slightly more rebound damping to keep ya from getting bounced off the trail. See our rebound & compression section to get the scoop on how to properly set these adjustments up, its really important stuff!
DVO Suspension is 100% designed, engineered, tested, and proven in the USA for riders by riders. We base all our designs from an Intelligent Engineering perspective, that means we build it with the consumer in mind regarding tuning, ease of servicing, cost of spare parts, manufacturing, reliability, and ultimate performance.
To help us get our ideas into reality, all the DVO products will be engineered using the most advanced design software and hardware available. Hardware requirements were so stringent that the company’s head engineer, Josh, had to personally spec and build out each workstation.
No expense was spared, with engineering at the heart of development and the ability to design, test, simulate, run FEA (finite element analysis) is paramount to designing and optimizing all our critical parts.
As shown on this example of the Strain Analysis of the new DH leg & Drop Out, the computer simulates a very high bending load and the blue color represents a cooler area (less stress) and red-orange color spectrum represents (increase in stress) warmer or hotter areas of strain. This is just one of many types of computer analysis/simulations we perform on all the structural components.
The next step is to perform the mechanical aspect of the testing process, bench testing. We will utilize different “bench test” protocols to test to the highest standards for strength and durability to ensure our computer simulations are in line with our physical test results.
And the most important and enjoyable part, we will have riders putting hours upon hours of ride time on our new products to verify the ultimate performance result because as we have learned from our decades worth of experience, the ultimate proof of design and engineering is how the product performs on the trail.
Another cool tool we use here at DVO Suspension is a 3D Rapid Prototype Printer which is great for verifying parts as you design them. We can even print various piston designs in the morning and be testing them on the trail in the afternoon. Having the ability to immediately verify a part right after designing it saves a lot of time and money. For example, after prototyping the axle and drop outs, we fitted them to a wheel and mounted a brake just to make sure we had the proper clearance and everything matched up. It’s a great tool to avoid making any small mistakes that can snowball into BIG problems.
FDM’s, better know as 3D printers are quite possibly the future of manufacturing across the globe. We have been on the waiting list for months now for this small “desk top” size machine and finally see the amazing results of this incredible technology. Our next investment will be a FDM that prints in different metal compositions so we can reduce the development and prototype time from months to just days. This allows for more testing time giving the engineering team a larger window to verify designs which greatly improves reliability and overall product performance. We won’t let a product come to market that’s not 100% Developed.
The use of thin steel shims is critical to the feel of any high-end suspension system and especially with the new DVO products. Our forks and shocks will be finely tuned with a generous combination of shim stacks to provide that stable and predictable suspension feel for both compression and rebound. Shims are used to restrict oil flowing through the holes or ports in a piston. Shims are configured in various diameters and thickness to achieve specific results as a “shim stack”.
The larger diameter shim that sits on the piston surface is the first shim to resist oil flow and generally affects the low-speed compression. The shims that are in the middle and furthest away from the piston’s surface affects the mid-high speed compression feel. When proper shim stack settings are achieved the end result is a bottomless feel on compression and a controlled/predicable extension that works in concert to keep your wheels planted on the ground. The main reason shim stacks are so amazing is that they are dynamic or speed sensitive and a proper stack can deliver a wide range of damping performance purely based on velocity.
Many companies use orifice or small holes to control compression and or rebound in their dampers, especially on lower end products. There are serious limitations to orifice dampers, under low speeds oil can easily flow through a hole but when speeds increase, oil flow becomes restricted and hydraulic locking occurs. Thats where a harsh feel on compression occurs or an unpredictable hopping of the front wheel on the rebound stroke can occur reducing traction and control.
A lot of mathematic calculations & years of tuning experience goes into our shim stack configuration. Below illustrates the use of a tapered stack that’s applicable for small bump absorbtion with a larger hit capability. Under Compression, oil is pushed through a port and lead into the shim stack. As the forces increase, the oil pushes open the shims. The shims create resistance to oil flow, which is your damping.
The shims that are first to be contacted by the oil create Low Speed Damping. The Crossover shim (#3) is to initiate a smooth transition from low speed to mid-speed damping. Shims 4-5 support mid level compression. As forces increase, the shims deeper into the stack start to resist which creates High Speed Damping. The thickness & diameter of the shims are critical for calculating damping settings from low-mid-high speed compressions. So why do tuners use a large number of thiner shims instead of a smaller number of thicker shims? The reason for using thinner shims is to prevent permanent distortion. If you were to take two shims, a thicker and a thinner one made of the same material and start bending them, the thicker shim will permanantley distort before a thinner shim does. Tuner’s then have to calculate how many thinner shims it takes to equal one thick shim. The result is a shim stack that will keep damping smooth and keep permanent distortion to a minimum.
If you’ve ever had the chance to check out the shim stack in a suspension fork or shock, chances are the shims are in a “pyramid” style stack-up. What is the reason for this instead of having a stack where all the shims are the same diameter? The common answer to this question is that the tapered shim stack adds a more progressive feel as they flex. This is not true. Both tapered and straight stacks are linear, meaning they gradually increase in stiffness as they are loaded
Tapered shim stacks also prevent permanent distortion of the shims. When the shims on a tapered stack flex, they all bend at multiple points spreading out the stress. Tapered stacks allow more clearance before they come in contact with the base plate. Shims on a straight stack all flex the same amount and bend on the clamping shim. The stress on the shims are concentrated at the bending point and the chance of permanent distortion is increased.
