Mountain Bike Sizing Chart With Tips and Tricks


mountain bike sizing chart blog header

This article provides a simple mountain bike sizing chart for men and women. It will help you find the bike size best suited for your body. You will have a better understanding of these topics:

  • How Is a Mountain Bike Measured?
  • Factors That Affect Your Riding Position on a Mountain Bike
  • Is Standover Height Important on a Mountain Bike?
  • Should Your Feet Touch the Ground on a Mountain Bike?
  • How to Modify and Adjust Mountain Bike Sizing

How Is a Mountain Bike Measured?

How Is a Mountain Bike Measured: Image of MTB parts
Figure 1: This photo by user Javier Carro shows the parts of a mountain bike with their Spanish and English names.

Most manufacturers have particular methods for presenting bike sizes to consumers. However, a good rule of thumb is to measure the lengths of the seat tube and top tube of your potential bike.

The seat tube is the part of the bike frame that connects the seat post to the bottom brackets. For classic bikes, this segment is the usual basis of bike sizing. When mountain bikes (MTBs) first emerged on the market, top tubes and seat tubes often shared the same length.

In recent years, alongside the introduction of BMX bikes, such as this one, MTB frames started to vary in shape, and elongated seat posts became widespread. This transition necessitated a new indicator to assist consumers looking to determine the appropriate bike size: the top tube length. Today, the top tube length has become the basis of bike size options.

How Is a Mountain Bike Measured: Image of bicycle frame parts
Figure 2: This diagram by Wikimedia user Keithonearth shows the basic parts of a bicycle frame.

Factors That Affect Your Riding Position on a Mountain Bike

When choosing a mountain bike, your first priority should be comfort. While sleek, large models may look good in photos, they may cause you bodily pain in the long run. You need to choose a mountain bike that fits your body. Here is one comfortable mountain bike option that many people love. You will have better command over your bike if you consider your comfort and height when making a purchase.

The best way to determine if your preferred mountain bike would be comfortable is to try it out. Make sure you can stand over the bike with enough clearance between the top tube and your groin to avoid collisions. The stem should also be long enough to allow you to reach the handlebars without any difficulty.

For more information, refer to the chart below, as it indicates why each part of your MTB should be a perfect fit for you. If you find yourself confused with the factors mentioned in this section, feel free to go back to the image above (Figure 1), which shows the different mountain bike parts.

Factor What Is a Good Fit? Why Does It Matter?
Frame When you do a standover, there must be enough clearance between your groin and the top tube. You should also be able to reach the handlebars, without your back feeling cramped or sore over time. An oversized frame can lead to backaches, poor bike control, and groin pains. A frame that is too small, meanwhile, can cause back problems, toe problems, and other injuries on long rides
Saddle Height The saddle is at the right height for you if your heel touches the lower pedal with your leg straight and the cranks in a top/bottom position. Your knees should only slightly bend when you pedal. A perfect fit in terms of saddle height will help you bike through difficult terrains. It can help you maintain your balance, control, and steering. It will also avoid saddle sores.
Saddle Tilt With a hardtail bike, such as this model, the most comfortable position is to have your seat as horizontal as possible. On a full-suspension bike, a slight tip toward the handle is better to make up for the sag of the rear suspension. If you climb more, tilt the nose down. If you descend more, tilt the nose up. The proper angle of your seat will help you avoid moving side-to-side with every pedal stroke. This orientation gives you more comfort over time and prevents chafing.
Fore/aft Saddle Position Push the saddle backward and ensure that your kneecap remains in front of the ball of your foot when you pedal. Saddles come in a variety of shapes and sizes, including this popular seat. Adjusting the fore/aft saddle position of your bike allows you to alter seat comfort to match your trail’s terrain.
Stem Height and Rise Stem height depends on your comfort level and purpose. Go with a lower stem height if you want precision when riding slow and more feel of the front traction. This configuration is better for flat trails and slow travels. Go with a higher stem height if comfort is your priority. This position will allow you to see better on steep trails. A good stem height allows for proper weight distribution, improving your balance and control on the bike.
Handlebar Width Generally, wider handlebars are preferred. However, stem lengths require reduction when you opt for wider handlebars to maintain comfort. For S-XL bikes, choose from the following widths: 650 – 680 mm, 680 – 730 mm, 730 – 750 mm. Handlebars that are wide enough give you more control, encouraging better breathing and improving balance.
Handlebar Sweep This measurement is the angle between the handlebar and stem. Upsweep is the bend up from the stem, while backsweep is the bend back from the stem. The former should angle at about 5 degrees, while the latter can vary from 5 to 9 degrees. If you’re into long-distance trails, you will want a backsweep of 15 degrees or more. Standard handlebar angles provide the needs of a typical trail rider. Wider angles ensure a more comfortable ride if you’re going to maintain your position on the bike for an extended period.
Bar Ends These pieces were bolt-on extensions for handlebars in earlier MTB models. While they are not as widespread today, they still have fans who swear by their usefulness during tours and long-distance excursions. Bar ends provide more control options and improve leverage. These additions are tremendously helpful when climbing uphill terrains. These bar ends are well-known options for mountain biking.
Top Tube and Stem Length The top tube’s effective length is measured from the center of the seat tube to the center of the head tube. While this length may often seem fixed, a variety of seat angles can change the effective length.   The stem length affects your reach and handling. Measuring the reach is more reliable than the effective tube length. The reach is measured horizontally from the center of the bottom bracket to the center of the head tube. If you want to adjust your effective top tube length, adjust your seat angle. A laid-back seat angle will provide you more room when sitting, while a steep seat angle will provide more space for standing.   A short stem provides better stability on steep downhill rides. However, a longer stem is essential if your bike’s reach is too short.
Crank Arm Length The crank arm connects the crankset of the bicycle to the pedals. Crank length usually indicates the distance from the center of the pedal to the center of the bottom bracket. Shorter cranks help provide a better position for the biker because you can lean lower on the bike. Team Sky, the British group that produced Tour de France winners, limit their cranks to 170mm (6.8”) or less.
Arm Positioning Bend your arms slightly when holding the bike. When you grip the handlebars, you shouldn’t be able to see the front hub. If your arms are in the correct position, you’ll be able to determine the reach of your bike. If the reach is too short, your back will be hunched and cramped. If the reach is too far, it can cause back pain over time.
Back Positioning Do not round your lower back or slouch as it limits your power and control. You can work out core muscles by sticking out your backside.   You will feel significant discomfort and pain in your back if you position incorrectly. Choose a bike that provides you with good posture for your back.
Upper Body Positioning Bend low to bring your chest close to the bars. Move your hips forward on the seat, bend your elbows slightly on the handlebars, and look up. You should feel yourself hanging on the bars. Keeping your chest low reduces the weight on your front wheel, improving your ability to steer. It will make long trails more comfortable and short climbs easy. There should be a balanced distribution of weight between the front and rear wheels.
Hands and Wrist Positioning When holding the handlebars, you should directly align your wrists and hands. Any bend in your wrists or fingers can cause pressure on your nerves. If you find difficulty doing this, relax your back and slightly bend your elbows. Improper hand and wrist positioning can lead to sore hands, numb wrists, and weak grips.

What Size of Mountain Bike Do I Need?

Many bike manufacturers present MTB sizes using custom bike charts. For example, this mountain bike from Mongoose lists theframe size. These charts suggest bikes based on the user’s height. While the sizes may vary from one brand to another, here is a general standard that applies to many models as compiled by EvansCycles.com:

Standard Mountain Bike Sizing Chart

Rider Height Suggested Mountain Bike Frame Size
Feet & Inches Centimeters Frame Size (inches) Frame Size (cm) Common Name
4'10" – 5'2" 148 – 158 13" – 14" 33 – 37 XS
5'2" – 5'6" 158 – 168 14” – 16” 38 – 42 S
5'6" – 5'10" 168 – 178 16” – 18” 43 – 47 M
5'10" – 6'1" 178 – 185 19” – 20” 48 – 52 L
6'1" – 6'4" 185 – 193 21” – 22” 53 – 57 XL
6'4" – 6'6" 193 – 198 23” – 24” 58 – 61 XXL

Women’s Mountain Bike Sizing Chart

While women can utilize standard mountain bike sizes without issue, some people prefer models specifically designed for female needs. This mountain bike is an excellent example of a woman’s MTB. If you want to purchase a woman’s mountain bike, here is a size chart to guide you from EvansCycles.com:

Rider Height Suggested Women’s Mountain Bike Frame Size
Feet & Inches Centimeters Frame Size (inches) Frame Size (cm) Common Name
4'10" – 5'2" 148 – 158 13” – 14” 33 – 37 XS
5'2" – 5'6" 158 – 168 15” – 16” 38 – 42 S
5'6" – 5'10" 168 – 178 17” – 18” 43 – 47 M
5'10" – 6'1" 178 – 185 19” and above 48 cm and above L

Bike Size Calculator

Bike Size Calculator: Image of leg inseam measurement
Figure 3: The leg inseam is measured from the ground to the point where your legs meet.

If you want to buy a mountain bike frame suited to your actual build, you need to calculate your specifications. One method is to measure your leg inseam, as recommended by Jeff Balton of Bicycle-Guider.com.

The following is a step-by-step guide on how to do this measurement:

  1. With your shoes off, measure the distance from the ground up to your groin area. Do this with your feet apart, preferably 6 to 8 inches from each other. This measurement is your leg inseam.
  2. Select the bike type that you want.
  3. With your calculator on hand, compute your optimal mountain bike size using this formula:

Leg Inseam (cm) x 0.66 = Your Frame Size

Is Standover Height Important on a Mountain Bike?

Standover height used to be the standard in determining bike fit, but current standards now rely on the effective top tube length. Nevertheless, many bike enthusiasts still consider standover height relevant because it saves your groin from a painful, numbing experience. Also, having enough clearance between your body and the bike allows you to stop and align the MTB easily, especially during emergencies.

When shopping around for your desired model, you should have at least 2 inches of clearance between the bike frame and your body. Professional riders may want 3 to 5 inches of clearance to give them more room to move. When considering these measurements, make sure you are wearing your cycling shoes for more accurate sizing. These mountain bike shoes are exceptional for hitting the trails.

Your inseam measurement is vital in determining your standover height. If you have a friend to help you out, you can measure your inseam using a book.

  1. Stand against the wall, with your spine straight and your feet planted on the ground 15 inches apart. Wear your cycling shoes during this process.
  2. Take a book and place the book spine just below your crotch.
  3. Have someone measure the distance between the spine of the book and the ground.
  4. The resulting measurement is your inseam.

With your inseam measurement on hand, check out the listed standover heights of various mountain bike brands. The difference between the two figures should at least be 2 inches, with the bike frame lower than your inseam. Those who bike more rugged terrains can go for a clearance of 3 to 5 inches.

Should Your Feet Touch the Ground on a Bicycle?

If it’s your first time trying out a mountain bike, you might wonder if your foot should be touching the ground when you pedal. The truth is, if your bike is a good fit for you, you shouldn’t be able to reach the ground with your foot unless you lean or tiptoe. If you can touch the ground without any difficulty, you might have to adjust your saddle height.

Your saddle height determines the power of your pedal. A well-proportioned saddle allows you to ride comfortably and avoid injuries, especially on long-distance rides. This particular saddle provides a remarkably comfortable ride.

There are different ways you can measure saddle height. A professional fit is best because it takes into account your body’s specific limits and tendencies. However, there are some easier methods you can try to get started on the bike. Here are two approaches:

The Heel-to-Pedal Method
  1. Sit on the bike while leaning against a wall.
  2. Position your heel on the pedal and backpedal to the 6 o’clock position. At this angle, your knee should be completely straight.
  3. If your knee is slightly bent at the 6 o’clock position, you should increase the saddle height gradually until your leg becomes straight without leaving the pedal.
  4. If your knee doesn’t reach the pedal at a straight position, you should decrease the saddle height until you do.
The LeMond Method - (Named after its most popular proponent, the ‘80s cyclist Greg LeMond)
  1. Remove your shoes and measure the distance from your crotch to the floor.
  2. Multiply the measurement by 0.833. The resulting figure is your ideal saddle height.

In the world of mountain biking, experts cannot fully agree on the best method to determine your ideal saddle height. This height may differ depending on various factors, including your body position on the bike, flexibility, cleat position, and style of pedaling. Overall, you should try different methods to see which one produces the most comfortable saddle fit for you.

Should Your Feet Touch the Ground on a Bicycle: Image of man biking
Figure 4: When riding a mountain bike, your elbows should be slightly bent, your chin should be up, and your eyes should be looking forward.

How to Modify and Adjust Mountain Bike Sizing

Sometimes, you only realize later that the bike you just bought is not a good fit for you. Rather than lamenting your decision, you can try some tried-and-true adjustment methods to improve the fit. While a significant discrepancy between your body size and bike can only be corrected by magic, if the bike is just slightly off, all hope is not lost. Check out some common customizations that you can do to get you up and pedaling in no time.

Bike Frame Is Too Small

Generally speaking, it is easier to adjust a bike that is too small than one that is too large. The following are some possible customizations for a bike that is too small:

  1. If your foot touches the ground as you pedal
  2. Adjust your saddle height. If you go beyond the recommended extension mark, it might be time to buy a lengthier seat post. This seat post is durable and adjustable. Consider the diameter requirement of your post if you need to replace the existing one of your bike.
  3. If you lean too far forward on your bike
  4. Loosen the bolts on the saddle rails and push it back until you are comfortable. You can also buy a saddle with a longer setback, but you need to make sure that your new saddle will fit the existing diameter of the bike.
  5. If the handlebars are too close to you
  6. Buy a longer stem if the handlebars seem too close to your body. However, remember that the length of the stem affects your steering control. With a longer stem, you might find it challenging to turn the bike in the right direction due to the increased distance from the pivot point. This handlebar stem is adjustable and fits most mountain bikes.
  7. If you feel unstable when you sit on the bike
  8. Raise the handlebars. While low handlebars increase traction, they may put you off-balance. Procure a stem with a high angle. Up to 15 degrees is available on the market.

Bike Frame Is Too Large

The following adjustments can work if the bike is too large for you:

  1. If your foot cannot reach the back pedal without tiptoeing
  2. Slide the saddle slightly forward. Alternatively, purchase a seat post with a design that bends it forward.
  3. If the bars are too far from your reach
  4. Shorten the stem of your bike. According to ilovebicycling.com, 50 mm is the shortest stem available on the market. Remember that stem length does affect bike control. This handlebar stem is a possible short stem option.
  5. If the handlebars seem too high for your reach
  6. Lowering the handlebars by putting the stem at its lowest point. You can replace the stem with one angled at 15 or more degrees.

We hope that you enjoyed this article on mountain bike sizing charts. Now you should have an understanding of how mountain bikes are measured, factors that affect your riding position on a mountain bike, what size of bike you need based on your height, how to utilize a mountain bike size calculator, whether standover height is important, and whether your feet should touch the ground on a mountain bike. You should now be ready to shop for a mountain bike! If you are interested, check out this related article that answers the question, “What mountain bike should I buy?”

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