High-tech suspension is all the rage these days. Riders are paying top dollar for remote-reservoir rear shocks or front fork cartridge kits instead of dropping a dime on a set of chrome wheels. But are they taking advantage of all the tunable benefits of these tricked out suspension components? Or is their purchase based on current market trends? Either way, we wanted to take some time to provide a bit more of the basics on how suspension works, and how to fine-tune your setup based on your riding scenario. You paid good money for that new shock or fork setup, you might as well take advantage of dialing it in properly!

We called up our old pal and suspension expert at Öhlins USA, Joey Subrizi, for his advice. Joey is an ex-road racer that has been working with Öhlins USA for over 13 years. He knows suspension. And he knows how to make it work, no matter the scenario. We asked him some questions to hopefully help you understand things a bit more clearly, and to make the overall suspension topic a little less intimidating.

When you’re ready to take the suspension purchase plunge, Joey says the first thing you need to ask yourself is: What is your riding scenario? Are you riding solo? Are you riding solo with a ton of gear/luggage? Are you more of a two-up rider? Do you and your passenger travel frequently with a lot of gear? Should you be riding a bike at all or should you be visiting Dr. Now? Your suspension choices should be dictated by these criteria. And more importantly, this information determines how you’ll fine-tune your new equipment. “If the rider is 300 pounds and the passenger is 100 pounds versus the rider being 200 pounds with a 150-pound passenger, that makes a difference,” Joey says. After that, Joey will recommend some options and which adjustments to make from there.

The other crucial component to making suspension work best is to set it up for your riding style. “Is it being used for more performance type riding or more for comfort?” Joey asks. “If you’re heavy and you ride a majority of the time two-up and your passenger is also heavy, and you ride with everything on the bike, including the kitchen sink, then I’m definitely going to recommend the hose mount reservoir shocks (HD 044)  because not only are they rebound adjustable, compression adjustable, but they also have the most stroke available.”

Once a customer chooses something based on their scenario and style, they’ll have a better idea what products are right for them. Once you’ve installed everything and it’s time to go for a ride, there is one crucial component that often gets overlooked when riders equip their motorcycles with new suspension products: Setting the rider’s sag.

“What is supercritical is setting the preload,” Joey says. “And the preload is the collar above the spring, determining how much you’re preloading that spring.” Basically, how much pressure you’re applying on that spring to compensate for the weight that’s being put on the motorcycle. When you’re setting up a motorcycle’s suspension, the key is when you sit on the bike itself, Joey recommends that the rider sits in one-third of the stroke. This means you have two-thirds of the stroke to deal with bumps, and the other one-third of the stroke to deal with the rear end being unweighted.

“Let’s say you get on the front brakes really hard and the rear end wants to be unweighted. We want the shock not only to compress when it hits bumps, but also to extend when it goes through a dip,” Joey says. “In turn, we’re setting it up based on the weight that’s on the motorcycle to be able to conform to whatever the road throws at the shocks. So setting preload is super critical as well on the rear shock, especially on something with a 1:1 ratio.”

REAR SHOCK :

We have a 2022 Low Rider ST and we wanted to update our suspension with some new Öhlins products. For the rear they recommended Öhlins HD 504 ($1,049) for 2020–2022 Harley-Davidson Softail Low Rider S, which features a large 46mm main piston, an internal gas reservoir within the main body of the shock, length adjustability, and a hydraulic preload adjuster.

With adjustable damping, you can change the behavior of the shock to suit your taste. This shock features a length adjuster that allows for a ride height change without compromising suspension travel. The hydraulic preload adjuster allows you to make changes without a tool to accommodate weight variations. And it does look pretty damn cool, too.

FRONT FORKS:

For the front fork, they suggested the Harley NIX 30 Cartridge Kit ($1,049) for 2020–2022 Harley-Davidson Softail Low Rider S (and now ST). Also known as the FKS 508, the Öhlins NIX 30 Cartridge Kit features compression damping in the left leg and rebound damping in the right leg. This allows for more precise function and stability. Adjustments are made at the top with the spring preload. Öhlins offers a service where you can send them your factory fork tubes, and they’ll install the NIX 30 Cartridge Kit for you. Because of the specialized tools you or your mechanic would need, I’d highly recommended going this route. And if your dealer is doing the swap, make sure they know what the hell they’re doing.

Our riding scenario is essentially solo (180 pounds including full-face helmet, leather jacket, riding boots, gloves, and full of piss and vinegar) with about 10 pounds in the bags.

ONLINE SETUP CALCULATOR:

Öhlins has an online preload adjustment calculator for bagger models, which factors in rider weight, passenger weight, cargo weight and then calculates how to fine-tune your preload. This is only for certain bagger models at the moment, but Öhlins is working on adding other Harley models soon.

SETTING SAG: 

Since Öhlins doesn’t have an online calculator set up for Softail models yet, we went with the more traditional approach for setting the sag on our 2022 Harley-Davidson Low Rider ST. I grabbed my 10-year-old-son Brody to help me with the measuring. He’s handy to have around!

1. On a level surface Brody measured the distance between the bottom of the rear axle and the bottom of the rear fender (12-½ inches).
2. We recorded this as our “unloaded” distance.
3. Then I sat on the motorcycle in my normal riding position with all of my gear on while Brody measured the distance between the bottom of the axle and the bottom of the rear fender (now 11-½ inches).
4. We recorded this as our “loaded” distance.
5. Then we subtracted the unloaded distance from the loaded distance to get the amount of suspension travel used by my scenario: solo with riding gear and minimal shit in the bags. We ended up with exactly a 1-inch difference from unloaded to loaded, which is where Joey said we should be. Anything more than an inch, we’d remove preload. Anything less than an inch, we’d add preload.
6. Adjust the preload on the rear shock to achieve the desired sag percentage. Our preload adjuster is a remote knob that we mounted on the right side cover.
7. Our preload was just right, but if you needed to, you’d turn the preload adjuster clockwise to increase preload and reduce sag, or counterclockwise to decrease preload and increase sag.
8. Repeat the measurement process and adjust the preload as necessary until the desired sag percentage is achieved.

It’s important to note that the front fork sag should also be set to match the rear sag. This can be done by adjusting the preload on the front fork springs in a similar manner. Once the sag is set, the rebound and compression damping settings can be adjusted to fine-tune the suspension for the rider’s weight and riding style. It’s recommended to consult the owner’s manual or a qualified technician for specific instructions on adjusting the damping settings.

SUSPENSION TERMS 101

Sag

The amount of compression that occurs on the suspension system when the rider is sitting on the motorcycle. Proper sag is essential for good handling and control of the motorcycle. Too little sag can cause the motorcycle to feel harsh and uncomfortable, while too much sag can make the motorcycle feel unstable and difficult to control.

Preload

Suspension preload is the term used to describe the amount of tension or load placed on the suspension system of a motorcycle when it is at rest, without any rider or cargo on it. In other words, it’s the force that is required to compress the suspension from its fully extended position.

Preload is typically adjusted by changing the length of the spring in the suspension setup. By increasing or decreasing the length of the spring, the amount of tension on the spring can be adjusted, which in turn affects the sag of the motorcycle.

To adjust the preload on a motorcycle’s suspension, the spring is compressed or extended using a preload adjustment tool. This adjuster is typically located on the top of the fork or on the shock absorber. In this case on our 2022 Harley-Davidson Low Rider ST, our preload adjuster is a remote dial that increases and decreases spring preload via a hydraulic knob. By turning the adjuster, the length of the spring can be increased or decreased, which changes the preload.

It’s important to note that preload should be adjusted according to the rider’s weight, riding style, and the intended use of the motorcycle. A qualified technician or the owner’s manual should be consulted for specific instructions on adjusting the preload for a particular motorcycle.

Compression

Compression damping is a suspension tuning term that refers to the resistance a shock absorber provides when the suspension compresses due to an impact or load. Compression damping helps to control the rate at which the suspension compresses, and it is adjusted to match the rider’s weight, riding style, and the road or terrain conditions.

When a motorcycle hits a bump or pothole, the suspension compresses to absorb the impact. Without compression damping, the suspension could compress too quickly and cause the rider to lose control or bottom out. Compression damping helps to slow down the compression rate, which allows the suspension to absorb the impact in a more controlled manner.

Compression damping is adjusted using a damping adjuster located on the shock absorber or fork. Turning the damping adjuster clockwise increases the compression damping and slows down the compression rate, while turning it counterclockwise reduces the compression damping and allows the suspension to compress more quickly.

Proper compression damping is essential for a comfortable and safe ride on a motorcycle. If the compression damping is too soft, the suspension will bottom out easily, causing the rider to lose control. If the compression damping is too stiff, the suspension will not absorb bumps and impacts effectively, leading to a harsh and uncomfortable ride. Please consult the owner’s manual or a qualified suspension technician for specific instructions on adjusting compression damping for your particular motorcycle.

Rebound

Rebound damping is a suspension tuning term that refers to the resistance a shock absorber provides when the suspension extends after being compressed due to an impact or load. Rebound damping helps to control the rate at which the suspension extends, and it is adjusted to match the rider’s weight, riding style, and the road or terrain conditions.

When a motorcycle hits a bump or pothole, the suspension compresses to absorb the impact. Once the compression phase is complete, the suspension extends back to its original position. Without rebound damping, the suspension could extend too quickly and cause the rider to lose control or experience instability.

Rebound damping helps to slow down the rebound rate, which allows the suspension to extend in a more controlled manner. Proper rebound damping helps to keep the tire in contact with the road or terrain, improves handling and stability, and reduces rider fatigue.

Rebound damping is adjusted using a damping adjuster located on the shock absorber or fork. Turning the damping adjuster clockwise increases the rebound damping and slows down the rebound rate, while turning it counterclockwise reduces the rebound damping and allows the suspension to extend more quickly.

Proper rebound damping is essential for a comfortable and safe ride on a motorcycle. If the rebound damping is too soft, the suspension will extend too quickly and cause the rider to lose control or experience instability. If the rebound damping is too stiff, the suspension will not extend effectively, leading to a harsh and uncomfortable ride. It’s recommended to consult the owner’s manual or a qualified technician for specific instructions on adjusting rebound damping for a particular motorcycle.

DID YOU KNOW?

After talking with Joey a little bit more about his experience with Öhlins, he hipped us to some cool company fun facts:

1. Öhlins supplies suspension components to 98% of the race teams for MotoGP.
2. In Formula One racing, Scuderia Ferrari uses Öhlins products exclusively in its race cars.
3. Here in the USA, every single race car running in Nascar right now is equipped with Öhlins suspension components.

Words: Jordan Mastagni Photos: Jordan Mastagni, Öhlins USA