How to Set Sag and Preload for Rear Suspension Like a Pro
If you’ve ever felt like your motorcycle wasn’t quite responding the way you expected—maybe it dives too much under braking, or feels vague when cornering—the problem may not be your tires, speed, or riding technique. More often than not, it’s your suspension setup, especially the rear sag and preload.
Setting sag and preload correctly can transform your riding experience. It’s one of the most impactful (and free) adjustments you can make to improve both comfort and control. Yet, many riders overlook it or assume it’s something only racers need to worry about. Truth is, everyone from weekend warriors to daily commuters can benefit from learning this simple setup process.
In this article, you’ll learn what sag and preload are, why they matter, and exactly how to set them step-by-step—even if you’re completely new to suspension tuning.
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What Is Sag and Why Does It Matter?
Sag refers to how much your bike compresses under its own weight and your body weight when it's standing still. It's a measure of how much suspension travel is already being used before you even start riding.
There are two types of sag:
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Static Sag (Free Sag): The amount the bike compresses under its own weight, without a rider.
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Rider Sag (Race Sag): The amount the bike compresses under the combined weight of the bike and the rider in full gear.
Too much sag? Your bike will feel squishy, unstable, and bottom out easily.
Too little sag? It’ll feel stiff, harsh, and lose traction on uneven roads.
The goal is to find that Goldilocks zone—where the rear suspension offers both support and responsiveness.
Understanding Preload
Preload is the tension applied to the rear spring to compress it before the suspension begins to move. It doesn’t make the spring stiffer; rather, it alters the ride height and the amount of travel used at rest.
Adding preload raises the rear of the bike, which can quicken steering but reduce comfort. Reducing preload lowers the rear, which improves straight-line stability but may hinder agility.
Proper preload ensures your suspension sits in the sweet spot of its travel, ready to absorb bumps and maintain traction.
Tools You’ll Need
Before you begin, gather a few simple tools:
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A measuring tape or sag tool
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A friend or assistant
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Bike stand or wall for stability
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Preload spanner (or socket, depending on your bike)
Having a buddy helps a lot—they’ll assist with holding the bike upright while you take accurate measurements.
Step-by-Step Guide to Setting Rear Sag and Preload
Step 1: Measure Full Extension
With the rear wheel off the ground and the suspension fully extended (using a paddock stand or center stand), measure from the axle vertically up to a fixed point on the tail section (e.g., the edge of the seat or frame). Note this number as "L1".
Step 2: Measure Static Sag
Put the bike on the ground with no rider or luggage, just the bike’s weight on the suspension. Bounce it a little to settle the suspension, then measure the same points again. Note this as "L2".
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Static Sag = L1 - L2
Ideal static sag is typically 5–15 mm for street bikes.
Step 3: Measure Rider Sag
Now, get into full gear and sit on the bike in a natural riding position. Have your assistant stabilize the bike and measure the same points. Record this as "L3".
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Rider Sag = L1 - L3
For road bikes, aim for 30–40 mm of rider sag.
For off-road bikes, 35–50 mm is typical.
If your sag numbers are outside these ranges, you’ll need to adjust preload.
Step 4: Adjust Preload
Use your preload adjuster (usually a stepped collar or hydraulic dial) to increase or decrease spring tension:
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Too much sag? Add preload (turn clockwise).
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Too little sag? Reduce preload (turn counterclockwise).
Make small changes, re-measure after each adjustment, and don’t rush it. You're fine-tuning your bike to fit you, not a generic rider profile.
Real-World Example: Ducati Monster 1200
Let’s say you’re setting up the sag on a Ducati Monster 1200. You’re 85 kg with gear. Your rider sag comes out to 50 mm—too soft for street riding.
You add three turns of preload using the spanner wrench and re-check. Now your rider sag is 35 mm—right on target. The next time you ride, you instantly notice better cornering stability, more precise throttle feedback, and less wallowing on hard acceleration.
It’s not magic—it’s physics dialed to your body and style.
Common Mistakes to Avoid
Many riders fall into the trap of adjusting suspension without understanding what they’re changing. Here are two key mistakes to avoid:
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Confusing preload with damping. Preload sets ride height. It doesn't stiffen your ride in terms of compression or rebound speed—that’s what damping adjusters are for.
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Ignoring your weight and gear. Set sag with everything you ride in—helmet, gloves, jacket, etc. Even a small difference can throw off your setup.
When to Revisit Your Setup
Your sag and preload settings aren't set in stone. You should revisit them when:
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You gain or lose weight
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You add luggage or a passenger
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You change tires or suspension components
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You switch between street and track use
Motorcycles, like people, evolve over time. Your suspension should too.
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Final Thoughts: Tune It, Feel It, Own It
Setting sag and preload might seem technical, but it’s really about making the bike yours. It’s the difference between a motorcycle that simply goes and one that truly responds. When set up properly, your suspension disappears beneath you—in the best way possible. The bike flows, connects, and reacts with confidence.
If you’re serious about performance or even just comfort, this should be one of the first things you dial in. And once you get it right, you’ll never ride the same way again.
If you're looking to take things further, consider upgrading your rear shock with adjustable options from Öhlins or protect your setup with Evotech Performance rear sliders and guards—available right here in our online store. Because the right setup, combined with the right gear, makes all the difference.