Adjusting your motorcycle suspension for your weight starts with how far the bike settles when you sit on it. Your body weight, riding gear, a passenger, and luggage all push the suspension down before the motorcycle even starts moving.
The first step is to measure that movement, which we call sag. You can then use preload to bring the bike into the correct range. If preload can't get you there, your motorcycle probably needs a different spring for the weight it's carrying.
Once the spring and sag are correct, you can adjust compression and rebound to control how the suspension moves. This guide walks through that process in plain language so you can make the right adjustment instead of using damping settings to cover up the wrong spring.
Adjusting for weight follows a specific order, and skipping ahead is the most common mistake riders make. Here's the sequence:
Each step only works if the one before it is right. If you adjust compression and rebound before your spring and sag are dialed in, you'll end up using damping clicks to mask a spring that's wrong for your weight, and the underlying problem never actually goes away. The rest of this guide walks through each step in that order.
A motorcycle spring supports the weight placed on the suspension. That includes you, your riding gear, and anything else you carry on the bike. As that total weight increases, the suspension settles farther into its available travel.
This matters because the suspension needs room to move in both directions. It has to compress when you hit a bump or transfer weight under braking. It also needs room to extend when the tire drops into a dip or weight shifts away from that end of the bike.
If you're too heavy for the installed spring, your motorcycle may sit too low before you even start riding. That leaves less suspension travel available for bumps, braking, and cornering. If you're too light for the spring, the motorcycle may sit too high and fail to use enough of its travel.
The correct adjustment order is straightforward. Start by making sure the spring can support your weight. Measure sag and use preload to set the ride height. Once those are correct, adjust compression and rebound damping.
We use your weight in full gear when selecting motorcycle springs and valving. Riding style and passenger weight matter too, since the total load and how you actually ride both affect the setup.
Preload gets mistaken for a spring-stiffness adjustment all the time. It's not. Adding preload doesn't change the spring rate. The spring still requires the same amount of additional force to compress it through each unit of travel.
What preload changes is how much the spring is already compressed when the suspension is fully extended. Adding preload raises the motorcycle within its suspension travel and reduces sag. Removing preload lets the motorcycle settle farther and increases sag. Preload adjusts the spring's initial load. The spring rate itself doesn't change.
That makes preload useful when the spring is reasonably close to the correct rate. A small adjustment may be all you need to account for riding gear, a passenger, or luggage. The problem starts when a large preload change is required just to get the motorcycle sitting at the correct height.
A spring that's too soft may need excessive preload to reach your target rider sag. The sag number might look correct with you on the bike, but the suspension can have almost no free sag left once you get off. That's telling you the preload is compensating for a spring that can't properly support the load.
A different pattern appears when the spring is too stiff. Even with most of the preload removed, the bike may not settle far enough under your weight. It can also show excessive free sag, because your motorcycle's own weight barely compresses the spring at all.
Preload has a useful range, but it can't turn the wrong spring into the right one. When your sag numbers only work at the extreme end of your available preload adjustment, the better fix is usually a spring selected for your actual weight.
Sag is the amount your suspension settles from full extension under load. Measuring it shows whether your motorcycle is sitting in a useful part of its suspension travel.
There are three measurements involved. The first is taken with the suspension fully extended. The second is taken with the motorcycle supporting its own weight, no rider. The third is taken with you in full gear, sitting in your normal riding position.
The difference between the fully extended measurement and the bike-only measurement is static sag, or free sag. The difference between the fully extended measurement and the loaded rider measurement is rider sag.
Rider sag is the main number we use to set your motorcycle for your weight. Static sag helps confirm whether the spring rate is correct once rider sag is dialed in.
For racetrack use, we recommend starting around 30 to 35 millimeters of front sag and 25 to 30 millimeters in the rear. For street use, the starting range is 35 to 45 millimeters up front and 30 to 35 millimeters in the rear. Your specific motorcycle and manufacturer specs can call for different numbers, so treat these as starting points rather than universal settings.
Measure sag with your motorcycle loaded the way you actually ride it. Wear your helmet, boots, jacket, and anything else you normally carry. A measurement taken without gear on doesn't represent the weight your suspension actually supports on the road or track.
It also helps to have someone else take the measurements while you sit naturally on the bike. Holding yourself up or leaning toward whoever's measuring can shift your weight and throw off the result.
Once you know your rider sag, add preload if the bike settles too far. Remove preload if it doesn't settle far enough. A ride height wrench makes that adjustment a lot easier on shocks with a threaded adjuster. Then check free sag to confirm the spring still lets the motorcycle settle under its own weight.
If you need a large amount of preload to reach the rider-sag target and the front suspension barely extends when the front wheel is unloaded, the spring is probably too soft. Too much upward movement with very little preload dialed in points toward a spring that's too stiff.
Stock motorcycle springs are usually selected to work across a range of riders and uses, which makes them a compromise by design. We account for rider weight, riding style, machine weight, track type, and other details before selecting the spring and valving for a custom motorcycle shock, since a compromise spring is exactly what leaves riders outside the average weight range running out of preload before they reach the correct sag.
A spring that's too soft lets the motorcycle settle too deep into its travel. You may find your rider sag stays excessive even after adding a large amount of preload.
The motorcycle may also burn through its travel too quickly under braking, acceleration, cornering, or bigger bumps. The front can dive heavily under braking while the rear squats more than expected on acceleration. Bottoming gets more common, since there's less travel left before the suspension hits its limit. A correctly sized bump rubber helps control the last part of the stroke, but it doesn't replace the right spring rate.
Another sign is very little free sag once rider sag is set. The added preload might be holding the motorcycle at the right height with you on it, but the suspension barely extends once you get off.
None of these symptoms prove the spring is the only issue on their own. Damping, tires, ride height, chassis geometry, and worn components can all create similar complaints. But the combination of excessive rider sag, limited free sag, and heavy preload is a strong sign your spring is too soft for your weight. Swapping to a heavier-rate spring is the fix, and Swift springs are another option when you want a lighter, more linear package.
A spring that's too stiff can keep the suspension from settling far enough under you. Rider sag stays below the target range even after you've backed off preload.
The motorcycle may feel harsh because your weight isn't enough to get the suspension using a practical amount of its travel. The wheel also has a harder time extending into dips or following uneven pavement when the suspension starts too close to full extension.
Excessive free sag is another clue. If the bike settles noticeably under its own weight but your added weight doesn't create much more sag on top of that, the spring may be too stiff for you.
Don't assume every harsh ride comes from a stiff spring. Excessive compression damping, slow rebound, friction inside the suspension, high tire pressure, or worn components can all cause harshness too. Stiction at the spring collar is worth ruling out as well, which is what a preload torrington bearing kit addresses. Sag measurements help you separate a likely spring-rate problem from an adjustment problem.
Once the spring rate is reasonably close, use preload to set your rider sag.
If the bike sits too low and rider sag is above your target range, increase preload. That compresses the spring farther at full extension and raises the motorcycle within its travel.
If the bike sits too high and rider sag is below your target range, reduce preload. That lets the suspension settle farther under the same weight.
Make preload changes in small steps and measure again after each one. Don't rely on the number of turns or visible lines on an adjuster. The actual sag measurement is what tells you what the adjustment did. A preload adjuster tool and a bearing and ride height wrench make small, repeatable changes a lot less painful than working with whatever came in the toolkit.
Write down your final preload setting once you reach the correct sag range. That gives you a known solo-rider baseline and makes it easy to get back to the same setup later.
A passenger and luggage add to the total weight your suspension supports. That extra load creates more sag and can leave your motorcycle sitting lower than it does with you alone.
Adding preload can bring the motorcycle back toward its normal ride height, and a hydraulic preload adjuster makes that kind of quick change easy to dial in.
Measure sag with your passenger seated normally and your luggage loaded where you'd actually carry it. Increase rear preload until the motorcycle sits back in an appropriate range for that setup. Write the setting down so you can switch between solo and loaded configurations without starting from scratch every time.
The size of the load change matters. A spring that works well solo may have enough preload range left over for occasional luggage or a passenger. A motorcycle that regularly carries a substantial passenger and touring load may need a spring chosen around that heavier operating weight instead. The 8900 Emulsion Single Adjustable was designed with exactly that rider in mind, and the rest of our touring rear shocks and cruiser rear shocks are built around loaded operating weights.
Trying to support a major load increase with excessive preload can leave you with little free sag and a suspension close to topping out once the load comes off. If you can't reach reasonable rider and free-sag numbers in both configurations, you probably need a different spring, or one selected around your regular load. Matching touring forks are worth looking at too, since a loaded bike changes what the front end has to do under braking.
Compression and rebound should only get adjusted after your spring rate and sag are correct. These adjusters control the speed of suspension movement. They don't correct a spring that can't support your weight.
Compression damping controls how quickly the suspension moves into its travel. Adding compression damping slows that movement down. Reducing it lets the suspension compress more easily.
Rebound damping controls how quickly the suspension returns after it's been compressed. A stiffer spring generally stores and releases more energy, so your rebound setting may need to change along with your spring rate. We select spring and valving together as a combination for exactly this reason, since damping is set up to work with the spring it's paired with, not on its own. Inside the shock, that valving comes down to shim stacks, bleed shims, and the adjustable needle that sets your click range. Our on-demand webinar walks through this in more detail with a live bike and rider demonstration.
If rebound is too slow, the suspension may not fully recover before the next bump, which can gradually ride the bike lower through a series of hits, a problem we call packing. If rebound is too fast, the bike can feel loose, springy, or unsettled as the suspension returns.
Start from the manufacturer's or shock builder's recommended baseline. Make one small adjustment at a time and ride the same section of road or track after each change. Record your original setting and every change you make so you can return to baseline if the motorcycle gets worse. Fresh suspension fluid matters here too, since damping changes as oil ages and heats up. Our motorcycle tools collection covers the wrenches and gauges that go with this work.
Weight matters here, but it doesn't create one universal damping rule. A heavier rider often needs a different spring, and the damping then has to be matched to that spring and how you ride. Don't just add a few clicks of compression because you weigh more than average.
Preload adjustment stops being enough when you can't reach the correct rider sag without ending up with poor free sag. You may need a different spring if your rider sag stays excessive with a large amount of preload dialed in, or if the motorcycle still doesn't settle enough after you've backed preload off. Frequent bottoming, topping out, or limited usable travel are additional signs.
A custom suspension setup also makes sense if you're well outside the weight range of your stock spring, you regularly carry a passenger or heavy luggage, or you use the motorcycle for road racing and drag racing. Those situations place more specific demands on the spring and damping than a general factory setup can always cover. The 8983 Double Adjustable is a common starting point for amateur racers and track day riders who want separate compression and rebound control.
If preload and spring changes haven't gotten you to the right sag numbers, it's time to talk to a specialist rather than keep guessing. Before you reach out, gather:
Visit our motorcycle products page or connect with a specialist through our S3 process, and we'll help you land on a spring and valving setup built around your actual weight instead of an average one.
Already running Penske shocks and need them serviced or resprung? Start a shock service request. If you'd rather work through a local shop, use the dealer locator. Ready to browse instead? Start with the motorcycle collection and narrow down by rear shocks, forks, or spare parts.
How do I adjust motorcycle suspension for my weight? Measure rider sag while wearing full riding gear. Add preload if the bike settles too far, and remove preload if it doesn't settle far enough. If you can't reach the correct sag while maintaining reasonable free sag, you need a spring rate that better matches your weight.
Does adding preload make a motorcycle spring stiffer? No. Adding preload changes the spring's initial load and reduces sag, but it doesn't change the spring rate. If a spring is too soft for your weight, adding more preload can't make it behave like a stiffer spring. The fix is a heavier-rate spring.
How much motorcycle sag should I have? Our general racetrack starting range is 30 to 35 millimeters in front and 25 to 30 millimeters in the rear. Our street starting range is 35 to 45 millimeters in front and 30 to 35 millimeters in the rear. Check your motorcycle or shock manufacturer's specifications, since the correct measurement can vary by application.
Do I need to change motorcycle suspension settings for a passenger? Usually. A passenger adds weight and increases sag, so additional rear preload may be needed to restore ride height. If you regularly carry a passenger or heavy luggage and can't reach good rider and free-sag numbers, a different spring may be the better fix. The 8900 Emulsion Single Adjustable is built for riders adding a passenger or luggage.
How do I know if my motorcycle spring rate is wrong? The strongest sign is not being able to reach your recommended rider sag while maintaining reasonable free sag. Excessive preload with little free sag points toward a spring that's too soft. Very little preload with excessive free sag can point toward a spring that's too stiff. If you're stuck, our racing shock services team can respring and revalve the shock around your weight.