MTB SAG Calculator | Calculate Fork and Shock SAG in Seconds

What is SAG?
SAG is the amount of suspension travel used when the rider sits on the bike in a normal riding position. It represents the starting point of your suspension setup and has a major influence on comfort, traction, stability and control.

Think of SAG as the balance point between support and compliance. Too little SAG can make the bike feel harsh, nervous and lacking grip. Too much SAG can make it feel sluggish, unstable and prone to bottoming out.

Both the fork and rear shock should be adjusted to achieve the appropriate SAG percentage for your riding style. Cross-country riders generally use less SAG for maximum efficiency, while Enduro and Downhill riders often use more SAG to improve traction and control on rough terrain.

Getting SAG right is the first step before making any rebound, compression or volume spacer adjustments.


How to Measure MTB SAG
Measuring SAG is a simple process that requires your normal riding gear and, ideally, the help of another person.

Step 1: Wear Your Riding Gear
Always measure SAG while wearing the equipment you normally ride with, including your helmet, shoes, hydration pack and any tools or accessories you typically carry.

Step 2: Prepare the Suspension
Move the O-ring on the fork stanchion and rear shock shaft against the dust seal.

Step 3: Assume Your Normal Riding Position

Get on the bike and adopt a neutral riding position with your feet on the pedals. Avoid sitting heavily on the saddle or holding the brakes excessively.

Step 4: Let the Suspension Settle

Gently bounce the bike a few times and then remain still to allow the suspension to settle naturally.

Step 5: Measure the Travel Used

Carefully step off the bike without disturbing the O-rings and measure how far they have moved.
Step 6: Compare With the Recommended Value

Use the MTB SAG Calculator above to determine the recommended SAG for your riding style and suspension travel.

Once SAG is correctly adjusted, you can move on to rebound, compression and progression tuning.

Recommended SAG for Trail Bikes

Trail bikes are designed to handle a wide variety of terrain, from technical climbs to fast descents. As a result, they typically benefit from a balanced suspension setup that prioritizes both efficiency and comfort.

A common starting point for Trail riding is:

This setup generally provides:

• Good climbing efficiency
• Predictable cornering behaviour
• Improved traction on loose terrain
• Better comfort during long rides

Remember that these values are only a starting point. Rider preference, terrain conditions and suspension design may require slight adjustments.

If the bike feels harsh and lacks grip, try increasing SAG slightly. If it feels vague or unstable, reducing SAG may improve support.

Recommended SAG for Enduro Bikes

Enduro bikes are designed to tackle aggressive terrain, steep descents and technical obstacles while remaining efficient enough for long days in the mountains.

A typical Enduro setup uses:

This combination provides:

• Strong front-end support under braking
• Increased rear wheel traction
• Improved control on rough terrain
• Better stability at higher speeds

Many experienced riders will fine-tune these values according to terrain and riding style. Riders who prioritize grip and comfort may choose slightly more SAG, while riders seeking maximum support may run slightly less.

The most important goal is achieving a balanced bike where both ends work together effectively.

Common SAG Mistakes

Even experienced riders sometimes make mistakes when setting SAG. Avoiding these common errors will help you achieve a more consistent and predictable suspension setup.

Measuring Without Riding Gear

Your body weight changes significantly when wearing a helmet, shoes, hydration pack and protective equipment. Always measure SAG in full riding gear.

Using Generic Values

Not every bike requires the same setup. Suspension travel, bike geometry and riding discipline all influence the ideal SAG value.

Ignoring Rear Suspension Setup

Many riders focus exclusively on the fork while neglecting the rear shock. Proper balance between front and rear suspension is essential for predictable handling.

Chasing Comfort With Excessive SAG

Adding too much SAG may initially feel comfortable, but it often reduces support, increases pedal strikes and causes excessive suspension movement.

Adjusting Rebound Before SAG

SAG should always be set first. Rebound and compression adjustments only make sense once the correct spring rate and ride height have been established.

Making Large Changes

Suspension tuning works best when adjustments are made gradually. Small changes often produce significant differences in bike behaviour.

A correctly set SAG provides the foundation for every other suspension adjustment and is one of the easiest ways to improve your bike’s performance on the trail.