Tuning Your UTV Shocks
Between A Rock And A Soft Space
UTVs are truly amazing production vehicles. They can fly through the desert or climb a mountain like a billy goat. With a stock UTV designed to cover such a wide range of terrains, there will inevitably be gaps in suspension performance. We are going to look at ways to improve your ride quality and performance from your UTV. We’ll walk you through how to tune your UTV for your driving style and terrain.
This is a general guide for a suspension setup, and it is hard to cover each UTV with the various shock options on each. Some UTVs will have multiple tuning options on the shocks and others may only have one, or sometimes there won’t be any tuning options. The most important consideration is being familiar with the vehicle you are working with and the type of driving you intend to do with it.
Also know that it’s nearly impossible to tune a vehicle to work perfectly in every situation and for every driver, so we are going to focus on what we consider the four main areas of terrain and work our way out from there. We will cover desert, sand, mountain/trail riding and rockcrawling. Within the Big 4 terrain styles, we should be able to cover almost every aspect of setup, which will allow you to modify as to achieve the best suspension settings for your UTV for your particular riding requirements.
It goes without saying that there will be a significant difference from a desert setup to a rockcrawling setup. We will go through key characteristics of each terrain style to help pinpoint the areas you will want to focus on while testing your setup. The strategies we are going to talk about are to be used as a guideline when tuning your UTV for your driving style and terrain. There are a plethora of factors to look at when setting up a chassis, but these are some basic settings that most UTV owners can tackle on their own and help everyone build their knowledge base on suspension tuning.
We will start off with some terminology commonly used when dealing with suspension. It is important to discuss a few of the terms before we dive into the shock settings but know that most of these terms will crossover to literally anything with shocks.
Ride Height: This term refers to the distance from the ground to the bottom of the vehicle.
Preload: Is the amount of pressure exerted on the shock springs before the vehicle is placed on the ground. This setting is often adjustable by threaded collars on the shock body. By raising or lowering the preload collars it will change the ride height of the vehicle.
Compression: Is the upward movement of the suspension towards the chassis, or the direction the suspension/ shock travels in relation to the impact of the bump or obstacle the vehicle has traveled over. Compression is a variable depending on vehicle speed and size of object the vehicle has traveled over.
Rebound: Is the downward direction the suspension travels after the compression stroke or the direction the suspension extends/ travels away from the chassis. Rebound is constant force determined by the stored energy of the suspension components at full compression/ bump. If the Rebound is too fast it can push the vehicle up into the air commonly called bucking.
Low Speed Compression: Is the compression force commonly associated with body roll and brake dive. Low speed impacts are smooth and gradual compression movement.
High Speed Compression: Is the compression force commonly associate with hitting a sharp edge like a pothole, rain rut, rock or any other object that causes the suspension to compress quickly. High-speed impacts are sharp/fast compression impacts.
Low Speed Rebound: Is the rebound force associated with body roll and acceleration weight transfer either front to back or cornering forces left to right. Smooth or gradual movement.
High Speed Rebound: Is the rebound force associated with how quick the suspension can extend to absorb the next impact. And is commonly associated with bucking.
As we mentioned, all production vehicles come from the factory with a general-purpose setup so there are many things to take into consideration when setting your suspension for your particular vehicle. The biggest factor is weight. All aftermarket accessories add weight. Like aftermarket roll cages, doors, spare tires, ice chests, race seats, bumpers etc…you get the point.
It is import to measure the ride height before and after your accessories have been installed. The other major factor for adding weight is passengers. For instance, you can easily add 800lbs of passengers to a four seat UTV (or two editors…). That does not include your spare tires, ice chests and so forth. So it is import to know how many passengers you plan on carrying on a regular basis. It is also a good idea to have a full tank of fuel when measuring ride height when accounting for any added weight when setting the ride height on the UTV.
Another important factor is tire pressure. Raising or lowering tire pressure can have a significant effect on ride quality so it’s recommended to have the same tire pressure each time to compare one setting to the next for consistency. This is where we highly recommend taking detailed notes of each change you make so you can refer to the original settings. The pros do this at every race, and you need to also as not every change will improve the ride quality and it may be necessary to go back to where you started.
Setting Ride Height and Pre Load- With all of you accessories installed, find a flat surface to park your UTV and measure the ride height. Sometimes it is tricky to find a consistent point to measure and you may have to get creative. Measure the front and back corners of the lower frame rails and then side-to-side to ensure the chassis is even. Once you have your measures we recommend referencing the Manufactures recommend ride height and make the necessary adjustments to the pre load to set the ride height if necessary.
The next step is checking each shock to ensure the compression and or rebound adjustments are even from left to right. It is very important to make sure the shocks are adjusted in tandem from left to right. Shock settings may be different front to rear of the vehicle, but the both the front (and rear) shocks need to be matched. Again, note these initial settings to reference later if necessary.
The first terrain we will dive into will be the Sand Dune setup. No matter where you are in the USA or anywhere else in the world, deep sand dunes tend to be very similar. They are typically smooth with large transitions from one dune to the next. There will always be some kind of cross chatter (where other vehicles have crossed each other’s tracks in the sand) or razor back dunes (Where the face of the dune has a gradual curve then suddenly tapers off on the back side).
Sand dunes are unique in the way it can simulate nearly floating. It is important to know how to dial in your suspension to maximize your comfort and confidence in your UTV. The “ideal” compression settings would be a soft initially to take up the small cross chatter but stiffen up in the large transitions (G- outs) like accelerating in to the face of a large dune. And the rebound settings would be fairly slow to keep the UTV from “un weighting” after a transition or large bump. The slower rebound will also help when transitioning the top of a razor back dune.
The second terrain is Traditional Desert. The desert terrain has a wide range of things from sand washes to shale hill climbs and silt beds. This style of terrain is a little harder to dial in because it is always changing but the good is that desert settings will work ok just about everywhere. In the desert, it’s common to drive across whoop sections, rain ruts and small to medium size rocks. If the UTV is too stiff the desert will take a toll on the occupants very quickly.
For desert terrain you want the compression settings as soft as possible without out bottoming out on medium- large size bumps. The suspension needs to be able to react quickly to absorb the impact and maintain traction on the ground. Some UTV’s have multistage compression settings. If your vehicle has this option you want to adjust the Low Speed Compression setting as soft as comfortable while increasing the High Speed compression until the vehicle does not bottom out on medium to large size bumps. The faster you are traveling, the more high-speed compression you will need to absorb the impacts though.
In many UTV’s, especially two-seaters, a common issue is bucking or kicking. That is when the rear of the UTV lifts or unweights after an impact or jump. It can be very unnerving, and dangerous, when this happens and can be caused by several things. This is where the Rebound settings come into play. The Rebound settings are important to ride quality and stability of the vehicle. You want the rebound in the front of the vehicle to be slightly quicker than the rear as this will help keep the chassis balanced, front to back, after an impact or in a whoop section.
The overall rebound should be set as quick as possible without causing the vehicle to kick or buck the rear end into the air. The reason we want the suspension to rebound and extend quickly is the frequency of the bumps. The faster you are traveling the quicker the suspension needs to return after an impact to absorb the next bump. If the rebound is too slow, the suspension will “pack up”. This happens when the when the rebound is too slow and cannot extend quick enough before the next impact and will cause the UTV to react erratically. By the fourth or fifth hit, it’s like there’s no shock action at all.
The next terrain we will talk about will be Mountain and Trail setup. The suspension setting for trails are a combination of desert and rock crawling. This setup should be rather forgiving as the average speed traveled is nowhere near speeds seen in open desert or on sand dunes, so you can soften the suspension quite a bit and not have to worry about bottoming out as much.
Trail riding is an area where ground clearance becomes a larger factor when setting the ride height on your UTV. Normally you want the vehicle, and its center of gravity, to be as low as possible, but there will inevitably be rocks, roots and ledges that you will have to clear as you make your way through the trails. So, you want to raise the ride height about 10% to prevent dragging the chassis on rocks and other obstacles in the trail. When the bottom of the chassis is raised by a rock or other obstacle, it reduces the amount of available traction on the tires and can cause you to spin the tires and possibly get stuck.
When setting the compression on the shocks for trail riding know that you’ll want a soft, supple ride. You want the tires to effortlessly roll over the obstacle in the trail without upsetting the chassis. If the compression is too stiff it can cause the vehicle to bounce or jump out of the tire groove, which as you can imagine can cause numerus problems. With the softer shock settings it will allow the tires to distribute the weight of the chassis evenly when climbing or descending on rough terrain.
The next setting we will look at is rebound. We want the rebound to be fairly neutral while trail riding. We want it slow enough not to buck or kick on high speed bumps, but it also doesn’t need to be super slow because we want the suspension to feel active while going over the rough sections. It is important to have the suspension rebound fairly quickly to absorb the small irregularities of the trail to maximize tire contact and traction but not too quickly. Responsive is all that is needed here.
The final area we will be discussing is Rock Crawling. This setup can be somewhat difficult to tune in properly. The speeds typically traveled while rock crawling are slow, which allows us a wide range of options. Ride height is a critical setting. We want to keep the center of gravity as low as possible without sacrificing bottoming out on the chassis while climbing. So the ride height can change from trail to trail.
Some trails are smooth-ish with smaller rocks and others have virtual boulders over which you are constantly traversing which would require a taller ride height. You want the compression settings very soft, most likely as soft as possible. And the reason for soft compression is you want the suspension to flex as much as possible without upsetting the chassis or throwing off the balance. If the suspension is too stiff it can cause the chassis to rock or teeter totter back and forth when climbing steep obstacles, which will not allow the tires to make proper contact with the terrain. This can be unsettling to the driver and possibly cause a roll over. The other factor when crawling is the rebound.
You want the rebound to be very slow while crawling. It is import as a driver to feel what the vehicle is doing when in extreme climbing situations. A vehicle that unweights or springs back too fast when on a steep incline can easily roll over. At very least, it will be very unpredictable when climbing. With the rebound settings slow it is easier to predict how the vehicle will react when on steep inclines or obstacles.
When testing it helps to find a short loop or follow a short trail when making adjustment so compare each setting. Make sure to take notes as you make changes as once you have a shock setting you like you can file it away and always go back to it if necessary. Driving in a consistent area will help determine if the changes you are making are really helping or not.
There are several companies that offer upgraded suspension components from stiffer springs to re-valving the shocks to improve the performance of the shock internally. And don’t forget that shocks need periodic servicing to keep them working at their best. Shocks are just like engines. They have many moving parts and oil/gas inside of them, so it’s important to have your shocks serviced just like your engines, to ensure the best ride quality and longevity possible from them.
Don’t be discouraged if the changes you are making are not helping initially. Shock tuning is an art and can take time and patience to get a vehicle set up how you like it. Know that when testing, you need to do the same runs at the same speeds. Consistency is key to getting accurate readings! Make only small adjustments at a time and take copious notes on what those settings are, but don’t be afraid to experiment with different settings to find out what works for you. We’ll be honest, taking the time to get your vehicle to react how you want it is a pain, but the result will be a vehicle that you’ll enjoy driving more and one that’ll be safer for you and your passengers.
(Editors note: Author Curtis Zamora is an ex professional downhill bike racer who then went to work at a shock company. He currently runs Rite Performance and is the guy we go to when we need someone to work on our shocks or to have something fabbed up. Just saying that he knows his biz.)