SAG Calculator

Q: How do I calculate SAG using the SAG formula?

You can calculate SAG in three steps: Determine the radius of the curvature . Compute the diameter . Apply the SAG formula : SAG = radius - √(radius² - (diameter / 2)²)

Q: What is the SAG for a 5m radius of curvature and 10m diameter?

The SAG will be 5 m . You can calculate this using the SAG formula here: SAG = radius - √(radius² - (diameter / 2)²)

Q: What factors affect the sag of a suspension system?

Several factors influence sag, including the spring rate , preload settings , the weight of the rider and any additional load , and the overall design of the suspension . Environmental conditions and wear over time can also impact sag performance.

Q: How does proper sag adjustment impact ride quality and safety?

Correct sag adjustment helps ensure that your suspension can absorb bumps effectively, maintain stability, and provide predictable handling . This not only enhances ride comfort but also contributes to safer vehicle dynamics by preventing issues like bottoming out or excessive rebound.

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Wei Bin Loo

Wei Bin is a Product Manager based in London, leading a technology company's Product and Data functions. With a keen focus on delivering top-notch technology solutions, Wei Bin empowers businesses to unlock their full potential through innovative products, data-driven insights, and an unwavering commitment to customer value. His passion lies in guiding companies toward growth and success, leveraging the power of technology, data, and customer-centric product solutions. At Omni, Wei Bin leverages his financial expertise as a Strategy Consultant and CFA Level 2 holder to create various financial tools aimed at helping people improve their financial literacy. Outside of his professional pursuits, Wei Bin is an avid wine enthusiast with extensive knowledge and certification in the field. He also enjoys the strategic challenges of chess and poker, as well as swimming in his leisure time. See full profile

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Reviewers

Steven Wooding

Steven Wooding is a physicist by training with a degree from the University of Surrey specializing in nuclear physics. He loves data analysis and computer programming. He has worked on exciting projects such as environmentally aware radar, using genetic algorithms to tune radar, and building the UK vaccine queue calculator. Steve is now the Editorial Quality Assurance Coordinator here at Omni Calculator, making sure every calculator meets the standards our users expect. In his spare time, he enjoys cycling, photography, wildlife watching, and long walks. See full profile

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With our SAG calculator, you can easily determine the sagitta using only two inputs: the circle’s radius and the diameter.

This tool is designed to enhance your understanding of:

What SAG is and the definition of SAG;
How to calculate suspension SAG; and
The application of suspension SAG.

We have also included practical examples to help you comprehend the process of calculation using the SAG formula.

To explore related tools, check out our resuspension calculator and diameter calculator.

What is SAG? SAG definition

SAG refers to the depth or drop of a curved line, essentially, how far the arc deviates from a straight line connecting its endpoints. It’s a concept used in various fields, from designing suspension systems for vehicles to crafting elegant architectural arches. By understanding SAG, you can better appreciate how curvature impacts performance and aesthetics.

This tool is designed to make it easy to grasp the underlying idea of SAG and apply it to practical scenarios without getting bogged down in the mathematical details.

How to calculate SAG

Now that we understand what SAG is, let’s explore an example to better understand how to calculate it.

Let’s assume the following:

Radius of curvature (R): 10 m
Diameter (d): 13 m

Compute the radius of the curvature.

The first step is to determine the radius of the curvature. For our example, the radius of the curvature is 10 m.

To understand this calculation better, you can use our radius of a circle calculator.
Determine the diameter.

Next, you can compute the diameter. In this instance, the diameter is 13 m.
Calculate the SAG.

The final step is to calculate the SAG using the following formula:

\quad \begin{split} \text{sag} &= R - \sqrt{R^2 - \left(\frac{d}{2}\right)^2}\\[1.4em] &= 10 - \sqrt{10^2 - \left(\frac{13}{2}\right)^2}\\[1.4em] &= 2.4007 \end{split}

Why is SAG important?

SAG is a crucial measurement because it determines the depth or curvature of an arc relative to its chord. In practical applications, such as suspension systems, having the correct sag is essential for ensuring that the suspension operates within its optimal range.

This balance helps maintain consistent wheel contact with the road, which in turn improves traction, ride comfort, and overall handling. Whether you're tuning a vehicle's suspension for performance or designing an architectural arch for both aesthetics and strength, understanding and accurately calculating SAG plays a vital role in achieving the desired outcome.

FAQs

How do I calculate SAG using the SAG formula?

You can calculate SAG in three steps:

Determine the radius of the curvature.
Compute the diameter.
Apply the SAG formula:

SAG = radius - √(radius² - (diameter / 2)²)

What is the SAG for a 5m radius of curvature and 10m diameter?

The SAG will be 5 m. You can calculate this using the SAG formula here:

SAG = radius - √(radius² - (diameter / 2)²)

What factors affect the sag of a suspension system?

Several factors influence sag, including the spring rate, preload settings, the weight of the rider and any additional load, and the overall design of the suspension. Environmental conditions and wear over time can also impact sag performance.

How does proper sag adjustment impact ride quality and safety?

Correct sag adjustment helps ensure that your suspension can absorb bumps effectively, maintain stability, and provide predictable handling. This not only enhances ride comfort but also contributes to safer vehicle dynamics by preventing issues like bottoming out or excessive rebound.