What Size Mountain Bike Do I Need? Your Guide to a Great Fit

Because the perfect sized mountain bike for your body will affect the comfort, handling, and safety of your riding, ensuring proper size is essential. 

If your mountain bike is sized too large or too small for you, it can result in the following comfort, handling, and safety issues:

There are several different measurements of a mountain bike, including the wheels, frame, seat, and handles. 

However, when determining what size mountain bike you need after taking your body measurements, begin with the size of the frame.

The frame size of your mountain bike will affect the agility, speed, and safety of your ride. Determined by your torso height, measure the proper frame size for your mountain bike by following these steps:

For example, if the measurement (in inches) from your crotch to your collarbone is 24 inches, then your frame size should be 20 (24 minus 4).

Ensuring your mountain bike seat is the proper size will go a long way in avoiding lower back pain and similar issues. Furthermore, the height of your seat will aid in appropriate control over the bike decreasing your risk of a crash. 

The size of your mountain bike seat is less determined by measurements, and more determined by the height and positioning of your body while you are using the bike. Take these steps to ensure the proper mountain bike seat sizing:

Another great tip on determining the proper seat height (if you are unsure of your leg extension percentage), is to sit on the bike seat and see where your feet land:

Another critical aspect of the mountain bike seat is the positioning of the seat (upward or downward). Because the proper positioning of the seat is closely related to the height of the handlebars, you can read more about seat positioning in the next section.

Much like the mountain bike seat, the handlebars are not so much measured in size as they are in height. 

When adjusting the handlebars on your mountain bike, it’s essential to take note that although the frame and seat of the bike are supposed to carry all your weight, your wrists and hands are not. So what does this mean in regards to the handle height?

If, when taking a mountain bike for a test run, there is a lot of pressure on your wrists against the handlebars, it can be indicative of two possible things:

Likewise, if you are reaching out (or up) for the handlebars, it could mean:

To ensure the handlebars are at the perfect height, first make sure your seat height (as detailed above) is proper. Perfecting your seat height first will lessen the number of seat adjustments you’ll possibly need to make so that there is no strain on your hands and wrists.

Once your seat is adjusted ideally based on your torso height, ride the mountain bike while taking note of how you are holding onto the handlebars. 

Determine if there is any pressure put on your wrists during your ride (as if your weight pushes into the handlebars from the front). If so, adjust the seat slightly backward until you can still easily reach the handlebars without your body weight adding pressure on your wrists, but not so far back so that you are reaching toward the handlebars with strain. 

Moreso, if your body weight is bearing down (on top of) the handlebars during your ride, raise the height of the handlebars until you can no longer feel that bearing down pressure. On the other hand, if your wrists are bent upright when holding onto the handlebars, you will need to
lower the height of the handlebars. 

You’ll know the height of your handlebars are perfect when you can reach them without strain, there is no pressure on your hands, and your wrists are straight and align with your arm (not bent up or down).

The size of your mountain bike wheels is not determined by your measurements or positioning, unlike the frame, seat, and handlebars. The size of the wheels is dependant on the performance desired on a specific type of terrain. 

Typically, mountain bike tires come in three diameter sizes: 26, 27.5, and 29. The following details how the tire sizes provide different riding experiences:

The frame size of your mountain bike needs to be determined first and foremost. However, once you’ve figured out your measurements and paired them with the perfect sized mountain bike for your body, you can shop to determine which model and type you’ll purchase.

To help you get an idea of mountain bikes for sale, take a look at these three mountain bikes (one for each wheel size), all with various speeds, tire sizes, and terrains, that you can find right on Amazon to be delivered right to your door:

The size 26 gray/green Merax Mountain Bike, priced at just $$ with a rating of 4 out of 5 stars, would be perfect for someone with a long torso. This mountain bike’s features include:

With four colors to choose from (black, grey, blue, and silver), the 18-inch sized Schwinn High Timber Mountain Bike is priced at $$ (marked down from $$!) with a rating of 3.8 out of 5 stars. This mountain bike features include:

The size 17 Vilano Blackjack Mountain Bike, priced at $$ with a rating of 4.5 out of 5 stars, includes these features:

If trying to ensure all these mountain bike measurements, heights, and sizes are correct for your body is too overwhelming, there is the option to visit a bicycle retailer in person. 

Bicycle retailers will typically have specialists on hand to help you select the perfect bike for your body type, in addition to having a more extensive selection of bicycle frames to choose. 

However, by following this simple guide, you can take the overwhelm and guesswork out of all that is entailed when determining the perfect mountain bike for you. 

When in doubt, always make size and height adjustments based on what feels most comfortable during your ride. With this guide paired with a focus on what feels best for your body, you will be guaranteed a safer, speedy, and agile ride on your new mountain bike.