How to Measure a Full Suspension Mountain Bike Frame

orange and black full suspension mountain bike

Full-suspension mountain bikes are designed for the roughest forms of off-road riding, which is why having the right fit is paramount.

By understanding how to measure a full-suspension mountain bike frame, you’ll be able to choose the right frame size based on your height and inseam length and experience benefits in comfort, performance, and confidence on challenging trails.

Our online calculator below will help you get an accurate frame measurement in seconds and tell you whether or not a particular frame size is the right choice for you.

Keep reading to find out more!

How to Measure a Full-Suspension Mountain Bike Frame?

full-suspension mountain bike measuring

To properly measure a full-suspension mountain bike, the most important metric you need is seat tube length. You can learn how to accurately measure it by following the step-by-step instructions below.

Once you know the length of your seat tube in inches, you can select it from the drop-down menu below, and you’ll receive a detailed rider size chart, showcasing the recommended height and leg length ranges tailored to that frame size.

This will make finding the perfect fit a precise and effortless process.


Frame Diagram


Measuring Instructions

  1. Identify the top of the seat tube, where the seat clamp holds the seat post.
  2. Identify the center of the bottom bracket (it's the axle that holds the crank arms together).
  3. Measure the distance between the two points (C-T) - this is the length of the seat tube.
  4. Record your measurement in both centimeters (cm) and inches (to the nearest half-inch).
  5. Select your bike size from the drop-down on the right to see a rider height chart.


Full-suspension MTB

Rider Charts

Once you know your bike's frame size, select it from the drop-down to see how tall riders should be to use this bike.


Center to Top (C-T) - This is the length of the seat tube, measured from the center of bottom bracket to top of the seat tube.

Metric (cm) - Road bikes are measured in centimeters.


Frequently Asked Questions

full suspension mountain bike frame size faq

1. How to measure the frame size of a full-suspension mountain bike?

Mountain bike frames are measured based on the seat tube length, though the top-tube length also matters when it comes to perfecting the fit. The seat tube is measured from the center of the pedal crank axle to the top of the seat tube. Moreover, all mountain bikes are measured in inches, while road bikes are measured in centimeters. 

2. How do I know what size bike frame to get?

To determine what full-suspension mountain bike frame size to get, you need to know your exact height and inseam length. Once you know these measurements, you can use a rider size chart or an online calculator to find the right frame size for your body measurements. 

3. What size is a 29er bike?

A 29er is a common name for a mountain bike with 29" diameter wheels. Contrary to popular misconceptions, this number has nothing to do with frame measurements, such as seat tube or top tube, and should not be used to determine the correct fit. 

4. What size is a 19.5 bike frame?

A 19.5" bike frame is a frame with a 19.5" seat tube length. Some manufacturers also label this size as Large (L), though this measurement is not as precise, since the size classes (XS - XXL) may differ slightly among different brands. 


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Measure Mountain Bike Frames - (Rigid | FS | Hardtail)

Measure Road Bike Frames - (Classic | Compact | Mixte)

BMX Bikes - (Freestyle | Racing)

Kids Bikes - (Balance | 12 | 16 | 20 | 24)