How To Measure Bike Wheel Size: Useful Tips (2021)

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Nowadays, there are many diverse types of bicycles for cycling purposes and their features on the market. For someone who is just starting with bicycles, choosing the right bike size is a little more complicated. But, it is important to your riding style and comfort.

Wheel size will affect the performance and the maneuverability of the bike. Have you ever wondered how to measure bike wheel size or what standard to determine the correct bike size? This article will help you solve your wondering about the size of a bicycle wheel.

International Organization for Standardization (IOS) for A Bike Wheel

International Organization for Standardization (IOS) for A Bike Wheel
International Organization for Standardization (IOS) for A Bike Wheel

International Organization for Standardization, abbreviated ISO, is an international standards-setting body that sets commercial and industrial standards worldwide.

ISO 5775 is the international standard for wheel sizing, including tire size and bicycle rim dimensions. This ISO system was initially developed by the European Tire and Rim Technical Organization (ETRTO).

ISO 5775 system is created to be a normative system in measuring bicycle wheel sizing clearly and adequately. Thanks to this system, the riders or bikers have the basis for calculating their wheel size, not based on ambiguous rules in the past.

Roles of The Wheel While Riding

Roles of The Wheel While Riding
Roles of The Wheel While Riding

The bicycle wheel is an essential part of a bicycle, particularly bicycle tire’s tread. The wheel is also the part that significantly affects speed and the feeling of driving on the road. The right pair of bicycle wheels will help you achieve a better and safer experience.

The bicycle wheels dramatically affect the feel and response during use. If the wheels are light, your movement will be faster. Not only that, lightweight tires will create a faster response, more flexibility when traveling on the road.

Therefore, understanding the advantages and disadvantages of bicycle wheels will help you a lot in choosing a suitable bike.

The wheel is attached to the shaft by a system of 36 metal spokes. The curls are arranged in a specific order and have the function of connecting the wheels and axles.

For a bicycle wheel, the tire and rim play an essential role, and they must be aerodynamic, durable, and light in weight. This affects the vehicle’s performance, acceleration, and handling.

Bicycle tires often have a width from 18mm to 25mm to minimize the road surface’s resistance. Besides, there is a smooth spine running along with the wheel on each tire not to create too much friction with the road surface, which increases the ride speed and increases tire durability.

You can purchase bike tires and bike wheels at a local bike shop. It will have various things for you, such as road tires, new tire, narrow tires, bicycle rims, measuring tape, fat tires, and so on.

Bicycle Wheel Size Explanation

16″ Wheels (ISO 305 mm)

16″ Wheels (ISO 305 mm)
16″ Wheels (ISO 305 mm)

16 inches is the smallest bicycle wheel size on the market today. This size is only used for adult bicycles when the rider requires compact dimensions. However, the stamina and quality of the bike will be significantly reduced. This size, however, is very suitable for children who are getting used to the bicycle.

When traveling on rough roads, a too-small wheel size can increase the frame’s impact and make your bike deteriorate quickly. Small wheels will make you feel uncomfortable when moving on gravel roads or even dangerous when encountering a plot hole.

What’s more, the smaller wheel circumference makes your cycle count more if you want to catch up with other bikes making the bikers consume more energy.

20″ Wheels (ISO 406 mm)

20″ Wheels (ISO 406 mm)
20″ Wheels (ISO 406 mm)

20 inches is the most common wheel size for BMX bikes. This is also the most popular size for folding bikes. This size wins the hearts of riders for its versatility and maneuverability. Stunning aerial jumps or fantastic techniques on the ground can be easily performed.

However, this size still has some shortcomings. Despite being more extensive than a 16-inch wheel, a 20-inch wheel is still affected by obstacles on the road such as rocks and gravel.

Small wheel sizes also require a unique bike frame size design to ensure a good driving posture. This will more or less affect the corner handling problem.

24″ Wheels (ISO 507 mm)

24″ Wheels (ISO 507 mm)
24″ Wheels (ISO 507 mm)

24 inches is a standard size in cruiser bikes or junior mountain bikes. This is also the preferred size of some riders with a larger body but loves the versatility of 20-inch wheels.

26″ Wheels (ISO 559 mm)

26″ Wheels (ISO 559 mm)
26″ Wheels (ISO 559 mm)

The 26-inch is the most popular size for mountain bikes for almost a century. This type of wheel is large enough to handle all kinds of terrain.

Nowadays, this type of wheel is increasingly used in vehicles that require stability when moving on complex surfaces such as gravel bikes or cyclocross bikes.

27.5″ Wheels (ISO 584 mm)

27.5″ Wheels (ISO 584 mm)
27.5″ Wheels (ISO 584 mm)

The 27.5-inch size offers many advantages over 26-inch wheels. The ability to overcome obstacles, more excellent traction and larger wheels help increase the number of turns to ensure momentum. In recent years, mountain cyclists are increasingly favoring this size of wheels.

29″ wheel (ISO 622 mm)

29″ wheel (ISO 622 mm)
29″ wheel (ISO 622 mm)

All the advantages of the large wheel mentioned above converge at 29 inches. Not only that, but the 29-inch wheel also enhances the benefit to the limit. 29” wheel is used popularly to road bike tires with a 622mm bead seat diameter.

However, due to the large size, it makes the force used for a one-time pedal more, causing more loss when climbing the mountain and losing the bike’s maneuverability.

Due to the larger bicycle rim size, the tire size is also wider. It is also true with mountain bike tire. These full-size wheels offer a better cycling experience and better ride quality.

For more information about Wheel Sizes, including mountain bike wheels, let’s watch a helpful video on:

Watch video: Wheel Sizes Explained | Kids Bikes, Mountain Bikes, & Unicycles

How To Measure Bike Wheel Size

How To Measure Bike Wheel Size
How To Measure Bike Wheel Size

So how do you know the size of your bicycle wheel? Here I will share some options that you can refer to measure your wheel size.

Option 1: Ask the bike shop

Ask the bike shop
Ask the bike shop

The first and easiest option is to ask a bike dealer at a bike store near you. Vendors will have specific specifications on the bike they sell. They will easily find out information regarding your wheel size quickly.

You can ask them to tell you your wheel size or advise you on the right wheel size to replace a new one.

Option 2: Check the printed parameters on the wheel

Check the printed parameters on the wheel
Check the printed parameters on the wheel

Most wheels today have a size parameter stamped on the tire. If you can’t look up your bike online, this is probably a pretty convenient option.

Each manufacturer will have regulations on how information is displayed on the tires, including mountain bike tires. According to ETRTO, a code will consist of 5 digits in the form of XX-XXX.

The first two digits represent the wheel width in mm. The last three digits represent the inner tire diameter in mm. For example, if your bike tire has the code 32-622, that indicates the tire’s width is 32mm, and the bike tire diameter is 622. Note that the tire’s diameter is very important.

Also, there is another rule that is Diameter x Width. For example, on the tire, you see the information 27 × 1.75. This means that the wheel diameter is 27 inches and the tire’s width is 1.75 inches.

For more information about Bike Tire, let’s watch a helpful video on:

Watch video: Bike Tires 101 : The basics of bike tire sizing

Option 3: Measure by yourself at home

Measure by yourself at home
Measure by yourself at home

If the two options above are not satisfactory, don’t worry. You can measure your wheel size with a few simple steps. The wheel’s size will be calculated by the wheel’s diameter together with the width of the tire. For the bike upright, bike tipping is needed. I will show you three methods to apply to your wheel sizing.

Method 1: Traditional method

Step 1: Fix the bike position
Fix the bike position
Fix the bike position

First, you stand the bike up to measure the most accurate wheel size. You can use a stand or lean the bike against the wall so that the bike position is upright. Do not let the bike lean on your body so that the measurement will be inaccurate.

Step 2. Measure the diameter
Measure the diameter
Measure the diameter

You use a ruler to measure the distance from the ground below the wheel to the wheel’s center. This will help you to calculate the radius of the wheel accurately. Then we need to multiply that value by two to get the wheel’s diameter. Most bikes are 26 to 29 inches in diameter.

For more information about Bicycle Parts, let’s watch a helpful video on:

Watch video: Bicycle Parts - wheel and tires size
Step 3. Measure the width
Measure the width
Measure the width

First, determine the width of bike tire and make sure your bike tire is inflated. Then use tape to measure the tire’s flat surface from side to side.

The tire size is highly dependent on the intended use. Large-width tires will often be used for challenging off-road trips to increase traction. Narrower treads give the rider a faster and smoother ride on flatter tracks. It is often in mountain bike tires. An additional information is mountain tires is so different to other bike tires, such as road tires.

Step 4. Remember the size you just measured
Remember the size you just measured
Remember the size you just measured

Once you have measured the tire’s diameter and width, the next thing you need to do is memorize them. You can remember the form Diameter x Width to facilitate buying the next bike tire or replacing a wheel in the future.

For example, if your measurement of the wheel diameter is 26 and the bike tire width is 1.75 inches, then 26×1.75 is the code you need to keep in mind.

Method 2: The ISO Method

Method 2 The ISO Method
Method 2 The ISO Method

ISO is the standard to define and evaluate bicycle wheel sizes used worldwide. ISO methods are considered the most reliable method because they give the most accurate measurement value.

According to ISO standards, the wheel’s size will include the bead seat diameter and the width of bike tire. All figures above will be given in millimeters, let;s round to the nearest inch. the diameter of the rim is also needed to calculate.

In case your ruler only measures in inches, measure and record the value in inches first. Then use a calculator to multiply the values ​​by 25.4 to get the measurements in millimeters.

Step 1. Measure the diameter
Measure the diameters
Measure the diameters

As with the traditional method, before proceeding with wheel sizing, make sure your bike is positioned upright. You can use a stand or lean against a wall or use a support device to prevent the tilting vehicle.

Then we use a ruler to measure from the center of the wheel to the tire’s inner bicycle rim to determine the rim’s radius.

Multiply that length by two to get the iso diameter. Finally, taking this diameter plus two times the tire’s width will get the diameter of the wheel.

Step 2. Measure the tire’s width
Measure the tire's width
Measure the tire’s width

This step is similar to the traditional method. We use the ruler to measure the tread’s surface from side to side. It is sometimes possible to use tires of different widths on the same wheel as long as the width difference is negligible.

Step 3. Take note of the measured parameters
Take note of the measured parameters
Take note of the measured parameters

According to the ISO standard, the wheel width is recorded first and then the iso diameter.

Let’s say you measure a rim diameter of 622mm and a bike tire width of 39mm. We will have 39-700. 700 is the wheel diameter measured from the tire’s outer edge from side to side.

It is calculated by the length of the rim radius of 622 plus the bike tire width of 38 times 2, which equals 78; we will have a wheel diameter of 700.

For more information about A Bike Tire Size, let’s watch a helpful video on:

Watch video: How To Read a Bike Tire Size

Method 3: Calculate the circumference of the wheel

Calculate the circumference of the wheel
Calculate the circumference of the wheel

We can understand that a bicycle wheel’s circumference is the distance outside the bicycle wheel circle.

The perimeter calculation will be necessary to calibrate the bike’s odometer. The change in wheel size will significantly affect your bike equipment’s data availability.

There are many ways to calculate the circumference of a bicycle wheel. Here are some techniques you can look for to get your wheel’s circumference at home.

Technique 1. Calculate by using circumference formula
Calculate by using circumference formula
Calculate by using circumference formula

First, we also measure the diameter of the wheel as usual. The diameter measurement procedure is the same as the two methods above. We also measure the wheel’s outer bicycle rim from end to end after fixing the bike’s upright position.

After determining the diameter, we multiply the wheel’s diameter by the number pi based on the circumference formula.

For example, we have a wheel diameter of 26 inches. We can calculate the wheel’s circumference as 26 multiplied by the pi as 3.14, which equals 81.64 inches.

Technique 2. Measure by a string
Measure by a string
Measure by a string

This is a fairly simple technique and does not require many tools. All you need is a piece of string.

You use the string to wrap evenly around the tire’s outer edge so that it forms a circle. Mark the point where the end of the line touches its starting point, then cut the rope.

Note that the string must be wound only one turn, and the winding line does not deviate, so the length of the cut string is accurate.

In the end, you need to measure the piece of string that you cut, and you’ll know the circumference of the wheel.

For more information about Measure Bicycle Wheel Circumference, let’s watch a helpful video on:

Watch video: How to Measure Bicycle Wheel Circumference For A Cycling Computer
Technique 3. Using a mark
Using a mark
Using a mark

This is also a pretty easy technique to help you measure your wheel circumference. You only need to use a drop of wet paint or tape to mark on your tires.

Then slowly roll your wheel in a straight line (super straight line) so that the mark on the wheel marks the road surface twice (determining the wheel’s radius). Then we measure the distance between them to get the wheel’s circumference.

For more information about measure your wheel circumference, let’s watch a helpful video on:

Watch video: How to measure your wheel circumference

BMX Wheel Size

Wheel Size (inches) Balance 12” 14” 16″ 18” 20”
Height (cm) 70-90 80-110 90-130 100-140 130-160 155-180

12 inches is the smallest wheel size for a BMX bike. This size is only used for children’s BMX vehicles. The size is suitable for kids just starting to get acquainted with bicycles.

This size ensures that your child’s feet can touch the ground for balance. Due to its small size, the bike frame size is re-designed to give the child the correct position and comfort while riding.

14” BMX Wheel Bikes

14” BMX Wheel Bikes
14” BMX Wheel Bikes

14-inch wheels are perfect for older babies between 90 and 1m30 in height. Suppose 12 inches is suitable for getting used to the BMX. In that case, the 14-inch wheel will be eligible for babies starting to learn simple charting techniques. 14-inch wheels will also help kids be more confident and comfortable riding on steeper and more challenging roads.

16” BMX Wheel Bikes

16” BMX Wheel Bikes
16” BMX Wheel Bikes

The 16 Inch is the most popular wheel size in the past among young riders. Before the size of 12 inches and 14 inches, 16-inch wheels were the manufacturer’s top choice.

16-inch fit wheels with rider height from 100 to 140 cm. 16-inch wheels are suitable for the rider who loves freestyle BMX.

18” and 20” BMX Wheel bikes

18” and 20” BMX Wheel bikes
18” and 20” BMX Wheel bikes

20 inches is the most popular size in BMX models. 18 inches is a great intermediate size for you to change the wheel from 16 to 20 inches. These wheel sizes are suitable for young people who love making a significant jump. 20-inch wheels give the rider a feeling of durability and flexibility when handling more demanding movements.

Conclusion

The information that I have just shared above will help you measure and choose the right bicycle wheel size for you. I hope you will have a great experience with your bike.

FAQs

What should I look for when choosing wheels for a road bike?

When choosing a wheel for a road bike, the first thing you need to consider is the wheel’s size. Road bike wheels usually have the size of 29 inches or 622mm rim diameter. You should also pay attention to some other factors such as bearing, wheel types, or spokes.

How do I find out my rim size?

We first measure from the center of the rim to the rim’s outer edge to get the rim’s radius. Then multiply the value by two ​​to get bead seat diameter. Next, we measure the rim’s width from the rim’s edge to the other edge of the rim.

What does a 26-inch bike mean?

A 26-inch bike means that the bike has 26-inch wheels.

The most popular wheels are 29 inches in size to ensure cornering grip and comfort. Some of the most famous road bike wheel series you can refer to are Zipp 303s Carbon, Vision SC 55, Hunt 36, Shimano Ultegra RS-700.

What is the diameter of a 20-inch bicycle wheel?

According to ISO, a 20-inch bicycle wheel will have a diameter of 451mm.

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About Jim Felt

Jim Felt, a man with a genuine love of speed. A man who designed his very first triathlon frame for Johnny O’Mara – the star of Motorcross at “The O-Show” – then got big successes in 1990. In 1994, Felt incorporated with Answer Products to launch his brand, starting a 7-year relationship until 2000. In 2001, Jim Felt relaunched the Feltracing brand in conjunction with Michael Müllmann and Bill Duehring. Our product lines were then expanded into a full line of commuter bikes, cruisers, MTBs, MBX, even road and tri bikes. The total number of models were up to 140 distributed in 27 countries.