How are bikes measure and Buying guides

If you are thinking of buying a new bike, you may be confused due to the many different sizes. We’ll show you How are bikes measured? so that you can self find the perfect bike for you.

Every time we think of riding a bike, the first thing we should be concerned about is if the bike size is right for you? What is the intended use for sports, fitness, or riding on the roads? With these thoughts, MultiCultiMobility would like to share with you some information related to “How are bikes measured?” to help you choose the appropriate bike for yourself.

How are bikes measured?

Wheel size is the diameter from the axle to the tire. In general, the wheel size will be listed on the tire. For example, a mountain bike can be 26 x 2.2 inches – it means that the wheel is 26 inches, while the tire is 2.2 inches thick. Bicycle wheels are classified by size suitable for each type of bike (road bike, tour bike, mountain bike and bike motor cross). For example, the wheel for the bike motor cross will be smaller and thicker to suit the stunts.

Bikes for adults are typically measured based on their frame size primarily. Most bike manufacturers now measure frames from the center of the crank axle to the top of the seat tube. For regular road bikes, they are usually measured in centimeters. On the other hand, for mountain bikes, the size is usually measured in inches.

For children’s bicycles, it is usually measured by wheel size instead of frame size. Typically, bikes with smaller wheels are lighter and easier to handle. However, children often grow very quickly so they quickly become uncomfortable and difficult to ride over time. Manufacturers often set stable sizes for children’s bikes. They are typically available in 12-inch, 24-inch, or 26-inch wheel sizes.

How are bikes measured


How are road bikes measured?

The road bikes are produced to go on flat paved roads. They are often designed with small tires, light frames. The saddle is designed for the rider to lean forward. You can choose this kind of vehicle to travel long distances and need high speed. The frame of most road bikes is usually designed to be slender, and will not withstand too long with large loads on bumpy off roads.

How are mountain bikes measured?

Mountain bikes are off-road vehicles with large tires and shock absorbers designed for combat on rough roads. This kind of bike is not as fast as a road bike and the sitting position is also not as comfortable as a road bike. However, its ability to fight on rough roads is impeccable. Riding a mountain bike, you will have to sit higher because the handlebars are designed straight.

How are mountain bikes measured

How are mountain bikes measured?

What size bike do I need? 

To answer this question, you need to finish the steps as below:

  • Step 1: Measure body height and inseam

To choose a bike with the right frame, you need to measure your body height and foot length (Inseam), which is measured from the crotch to the ground. After measuring, you will use 2 correlating tables of bike frame size (one for mountain bike and one for road bike) with human stature to choose the right bike for you.

  • Step 2: Measure the bike frame

As noted above, the frame size should be appropriate for your stature. If you choose a bike with a frame that is too big, it will be very difficult and uncomfortable to ride. Conversely, if the bike has a frame that’s too small, you won’t be able to get the full stride to maximize pedaling power.

For road bikes, touring bikes and city bikes, if the distance between the crotch and the horizontal tube is 1 inch (1.6cm), it’s the right size bike for your stature. For mountain bikes, that distance should be larger.

Similarly, for children’s bikes, the best way to find the correct size bike is to let the child sit on the bike. If your child can completely put his feet on the ground and his arms reach the handlebars completely comfortably, then it is the right bike. In addition, when the child is on tiptoe, the distance between the crotch and the saddle about 25 to 50 cm is appropriate.

  • Step 3: See the saddle position of the bike

Some people like the saddle slightly tilted forward or backward, but most prefer a straight saddle because they don’t like the feeling of slipping forward or after riding. Normally, it will take some time and a few tries before you know what saddle is right for you. But basically, the saddle should be arranged so that your feet can rest comfortably on the pedal. When pedaling, your legs can be fully extended downwards, and your buttocks are held in place, not skewed to the sides.

  • Step 4: See the position of the handlebars

In fact, the position of the handlebars is very important, but many people do not pay attention. The wrong handlebars can lead to back pain, shoulder pain and wrist pain when pedaling. In addition, the handlebars are designed to match the size of the chassis, so there will be many different sizes. Regularly, for road bikes and touring bikes, users should choose a bike with shoulder-width handlebars.

If you want to straighten your back and be able to look around and not have to crawl into the bike, you can set the handlebars higher. In fact, such a slightly upright posture will reduce aerodynamics and slow down the vehicle speed, but the posture will be much more comfortable. However, no matter how you adjust, you should not over-adjust, otherwise, you may damage the vehicle layout or worse, damage the handlebars.

  • Step 5: Select the pedal

To ensure that when cycling, your feet can move smoothly with the pedals, you should consider choosing pedals without clamps or toe pedals. Normally, with a clamp pedal, you can rest assured that you will not slip off the pedal. The only downside of this pedal is that it is often bulkier than a regular pedal.

Pedals for each different vehicle are also different. Ordinarily, mountain bikes will use double-sided pedals, making the process of cycling on rough terrain easier.

What size bike do I need

What size bike do I need?

See more:

How are bikes sized?

After you have briefly understood the bike models, you should know how to choose the right bike size for you.

The fastest way to estimate is to stand upright, feet flat on the ground, chassis centered. For road bikes, the distance between the tube and your crotch should be from 2.5 to 5 cm. For mountain bikes, this distance should be wider, about the width of your hand.

Frequently Asked Questions

1. Should we choose a mountain bike with wheels of 26 inches, 27.5 inches or 29 inches?

The wheel is one of the important elements that make up the bike, which many people are interested in when buying a mountain bike. Because the wheel is the part that is in direct contact with the ground, it affects the speed of movement, grip, and ability to cross rocky terrain. Choosing the right pair of wheels helps you improve your cycling technique and get high results in competition.

26-inch wheels are lighter than those with 27.5-inch wheels and significantly lighter than 29-inch wheels. The lighter the bike, the easier it is to control and the higher speed helps you to reach the finish line faster. Moreover, the 26-inch wheels easily maneuver through complex terrains that constantly change, requiring skilled riders to quickly handle unexpected situations.

Should we choose a mountain bike with wheels of 26 inches, 27.5 inches or 29 inches

Should we choose a mountain bike with wheels of 26 inches, 27.5 inches or 29 inches?

The larger the wheel diameter, the lower the collision angle. The shallower the angle, the smaller the impact, and the easier it is to overcome large obstacles. Therefore, 29-inch wheels have a greater advantage than 27.5 and 26-inch wheels when going on steep rocky terrain.

Counting for the same rotation, the larger the wheel diameter, the farther the wheel rolls. This is the biggest advantage of the 27.5 and 29-inch wheels while 26-inch wheels are rated to have a slower travel speed.

Wheel diameter is directly related to the area of ​​the tire in contact with the road surface. The larger the tire contact area, the higher the grip on the road surface, which is also a drawback of the 26-inch wheels, so the ability to grip the road is worse than the 27.5 and 29-inch wheels.

The most important thing is to choose the right wheel diameter for your height.

2. If I am 1.65 meters tall, what wheel size should I choose?

If you are 1.65 m tall, it is not suitable for 29-inch wheels. Because if you ride on 29-inch wheels, you will struggle on the bike. You can only ride a bike with 26 or 27.5-inch wheels. Most of the 26-inch, 27.5-inch wheels are suitable for Asian people’s height.

3. How to choose a mountain bike according to your height?

After you have thoroughly researched the bike brand you want to buy, you should read the information related to height when buying that brand’s mountain bike. Because bike brands use different conventions for sizing bikes. For example, the Giant bicycle brand divides by size XS, S, M, L, XL while some other brands divide by the length of the stand tube 48, 49, 50, 51, 52.

For example: 

You are planning to buy a Giant brand Rincon, ATX, XTC mountain bike and you are 1.63m tall. This means you can ride both XS and S sizes. However, there are some specially designed bikes that require a different size chart.

Once you have determined your goal is to increase comfort or improve skills in the bike, this will ensure where you sit on the bike to maximize your cycling performance. The technician will help you locate the contact points with the pedals, saddle and handlebars adjusted to the correct posture.

How to choose a mountain bike according to your height

How to choose a mountain bike according to your height?

4. Should I adjust my bike size after buying them from the store?

You need to know that buying a pre-assembled car in a shop without making any adjustments is completely wrong. The reason is that everyone’s height is different, no one is the same, even twins. Before taking the bike out of the store – the bike you buy must be properly adjusted by a technician according to your height and body shape. At this time, do not forget what you read in this article.

Closing Points

Choosing a bike size depends on your bike type, height, riding style, and preferences. A well-fitted bike will be more comfortable, efficient and happy to ride. This topic “How are bikes measured?” provides you with general advice on choosing the right size. This is a guide only and we always recommend our client visiting the bike stores for a hands-on experience.

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