Introduction
Rider sag is one of the most critical settings to ensure your motocross bike performs at its best. It plays a key role in balancing the suspension, allowing your bike to absorb terrain bumps while also providing the right amount of comfort and control for the rider. In this guide, we'll walk you through how to check and adjust your rider sag, step by step.
What is Rider Sag?
Rider sag refers to the amount the suspension compresses under the rider's weight when they're sitting on the bike in riding position. Proper rider sag is essential for optimal handling, comfort, and stability. If the sag is too high or too low, it can negatively affect the bike’s performance, making it harder to control.
Why is Rider Sag Important?
Adjusting your rider sag ensures that your suspension is set up correctly for your weight and riding style. The correct sag allows the bike to balance properly, helping with traction, stability, and shock absorption. Too little sag means the suspension is too stiff and may result in a harsh ride, while too much sag means the suspension may be too soft, leading to poor handling and potential bottoming out.
Tools You Will Need
Before you begin adjusting your rider sag, you'll need the following tools:
- Measuring tape: A flexible tape measure for measuring sag.
- Wrench: To adjust the suspension settings.
- A helper: A friend or teammate will be necessary to help you take accurate measurements.
Step-by-Step Guide to Check and Adjust Your Rider Sag
1. Set Your Bike on a Stable Surface Ensure your bike is stable and upright on level ground, preferably with a stand. The rear suspension should be in its fully extended position with no load on it.
2. Measure the Static Sag (Without Rider) To measure static sag, use the measuring tape to measure the distance between two points on your bike's rear suspension. A common way to do this is by measuring from the axle to a fixed point on the rear fender or shock. Record the measurement.
3. Take the Rider Sag Measurement Now, have your riding gear on and sit in a normal riding position on the bike. Make sure you're in a neutral stance, without leaning forward or backward. Your helper should measure the distance again between the same points you used in the static sag measurement. The difference between the two measurements is your rider sag.
4. Check Rider Sag Measurement Against the Recommended Range Typically, the ideal rider sag for motocross bikes is around 30–35% of the shock’s total travel. For example, if your rear shock has 300mm of total travel, your rider sag should fall between 90mm and 105mm. Check your bike's manual for specific recommendations for your make and model.
5. Adjust the Sag If your rider sag falls outside of the recommended range, you'll need to adjust it. The adjustment is made by either tightening or loosening the preload on your shock. Here's how you can do it:
- To decrease sag: Tighten the preload. This will increase the spring’s resistance and prevent the shock from compressing too much.
- To increase sag: Loosen the preload. This will decrease the spring’s resistance and allow the shock to compress more easily.
6. Re-check the Sag Once you've made adjustments, re-measure the sag with the rider on the bike and check that the measurement falls within the recommended range. It may take a few attempts to get it just right, so don't hesitate to make small tweaks and check each time.
7. Fine-Tune Based on Riding Conditions Once you have the correct rider sag, you may also need to adjust it slightly depending on the type of terrain you'll be riding. For example, more aggressive riders or those riding on rougher tracks may prefer a slightly firmer setup, while casual riders or those on smoother terrain might benefit from a softer setup.
Conclusion
Properly adjusting your rider sag is essential to getting the most out of your motocross bike’s suspension. By following these steps and making sure your suspension is dialed in for your weight and riding style, you’ll improve your bike’s performance, comfort, and handling. Regularly check and adjust your sag to maintain the best ride, especially as your riding style or bike settings evolve.