What size bike do I need?

Many factors determine the right bike size. These factors range from the type of bike you want to your height, riding style, and unique preferences.

You’ve probably seen a kid ride an oversized bike or a grownup ride a tiny bike. Maybe you’ve done it yourself. While it’s fun to ride the bike that comes to sight once in a while, you need to choose the right bike size if you are searching for an everyday bike.

The benefits of choosing the correct bike size range from improved comfort to more efficiency. The right-sized bike is also more fun to ride, and you don’t need to worry about injuries. Most importantly, you’ll be able to shop for a bike online and get the size right without testing it physically. Online shopping is on the rise today as people incorporate measures like social distancing brought about by the COVID-19 pandemic.

Without determining the right bike size for you, it will be hard to shop for the right bike online going forward. Our bike size charts and information below will make it possible to buy the perfect-sized bike today without visiting a bicycle shop physically.

We’ve gone through the trouble of discussing everything you need to know about bike size below, including providing bike size charts that make it easy to pick the right bike fast and easy depending on the variable/s in play. But first things first! You need to understand how bikes are measured.

How are bikes measured? How to measure bike size

Bikes are measured using seat tube length, which is the distance from the center of the bike’s bottom bracket (BB) or center of the bolt attaching the crank arms. The measurement can differ based on the bike brand. Some brands measure to where the seat tube and top tube meet while others measure from the middle section of the top tube.

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The measurement is usually given in centimetres or inches alongside descriptive sizes. For instance, mountain bikes are measured in inches or as small, medium, etc. Road bikes are measured in descriptive sizes i.e., small/medium/large, or centimetres. Hybrid bikes are measured in centimetres, inches, or descriptive sizes. It’s also worth noting that bikes get longer as they increase in size. The increase is relative to a bike frame size. However, different brands can have different-sized bikes (longer or shorter).

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Measuring your height

Now that you know how bikes are measured, it’s time to measure your height. As mentioned above, the best bike size for you will depend on several factors, including your height. Even if you know your height, there is a specific way to measure height when searching for the perfect bike size.

To do this, remove your shoes and stand against the wall and mark your height at the top of your head using a pencil. Your legs should be 6 to 8 inches (15 to 20 cm) apart when taking your height measurement. Proceed by measuring the height from the floor to the pencil mark. You can have someone to help.

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Important: If your height is within the size range, you need to consider your reach before making a bike size decision. You can determine your reach by measuring your ape index, which is: arm span minus height. If your ape index is positive, choose a long reach. If negative, go for a short reach.

How to measure your inseam

You also need your inseam measurement to get the right bike size for you. It’s worth noting that the inseam measurement used when buying jeans is different from the one used for bike sizing. The bike-one is at least 2 inches shorter.

To find your inseam length for bike-fitting purposes, start by removing your shoes and baggy trousers. Proceed by standing against the wall with your feet apart (6 to 8 inches). Place a book, spirit level, or anything else with a straight edge in your crotch. Pull it to the highest position to pressure when riding a bike. The straight edge should be parallel to the floor. Finish by measuring the distance from the floor to the top of the book or spirit level. Have someone to help to make the process easier. To get an accurate inseam measurement, repeat the process several times and use the average as your final inseam measurement.

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Accurate inseam measurement is important for comfort when you straddle. An accurate height measurement will ensure you get a bike that matches your upper body dimensions perfectly.

These measurements will only get rid of bikes that are too short or too tall for you. While the height and inseam measurements will edge you closer to finding your bike size, you need to make more considerations.

Stand over height

A bike’s standover height is the distance between the frame and the ground. The measurement is taken from the ground to the top-tube. For unmatched comfort, you should have a 2cm clearance between your and your bike’s frame.

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The clearance also prevents injuries when you need to get on the bike or jump off the saddle. In theory, standover height is simply the leg measurement minus two centimeters. You should measure your inside legs while wearing your cycling shoes to get your standover height.

The type of bike

The type of bike you want will also dictate sizing. Different bikes are made for different applications. For instance, mountain bikes are ideal for aggressive riding in mountain-like conditions. Such bikes need to be more maneuverable than the typical bike. It is better to pick a smaller size than you would when selecting a typical bike.

On the contrary, a cross country cyclist looking for a fast and flatter mountain bike may prefer a larger than normal size. In a nutshell, the “line” between right and wrong size may be blurred in some specific cases. However, there are some general sizing guidelines to consider based on the type of bike you want.

a. Road bike sizing

Road bikes are either sportive or racing. Sportive road bikes tend to have higher front ends and shorter top tubes for extra comfort. Racing road bikes tend to have lower front ends and longer top tubes for faster riding. There are other types of road bikes like cyclocross bikes, which are designed for more casual off-road riding. Other types include adventure road bike for a more adventurous ride (mix of roads, trails, and terrains). Adventure road bikes tend to be lightweight with a drop-bar.

In case you are wondering what road bike size is perfect for you, see our road bike size chart below. After taking height, inseam, and standover height measurement above, you shouldn’t have a problem selecting the perfect road bike for you.

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b. Mountain bike sizing

As the name suggests, mountain bike are for mountain-like or off-road riding applications. Typical mountain bikes come with a 25-inch wheel. However, there are other sizes available today i.e., 27.5-inch and 29-inch. The larger sizes offer more speed and better riding experience on bumps. Mountain bikes are measured in descriptive frame sizes i.e., S, M & L, or inches.

Here’s a mountain bike size chart to help you pick the perfect size for you based on your height, among other measurements.

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c. Hybrid/City/Commuter bike sizing

A hybrid, city or commuter bike is a bike designed for common applications like leisure riding or commuting. Hybrids incorporate the designs of other bikes. For instance, they look like mountain bikes but tend to have narrower and smoother tires. They may also look like road bikes with flat handlebars.

Here’s a hybrid bike sizing chart to help you get the right hybrid bike size for you based on your height, among other factors.

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d. BMX bike sizing

BMX bikes are popular for racing and/or performing tricks. They tend to be designed with one frame size. However, there may be variations in length. The wheel size can be changed to match a rider’s age or height. The style and size differences vary between the two main types of BMX bikes i.e., Freestyle BMX and Race BMX.

Here’s a BMX bike sizing chart to help you get the right BMX bike size for you.

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e. Kids bike sizing

When selecting kid’s bikes, you need to consider the models in specific age ranges and match those with your kid’s height to get the right bike size. Kid’s bikes are simply “small” versions of adult bikes measured mainly by wheel size.

Important: The perfect-sized bike for your kind is one that allows your kid to sit on their new bike with both feet touching the ground.

Here’s a kid bike sizing chart to help you choose the right kid’s bike size for your kid. You’ll need to measure your kid’s height accurately and consider other factors like their age and inside leg measurements.

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The above bike sizing charts and guides summarize everything you need to pick the best bike size for you or your child. Armed with the above information, you can buy any bike online and enjoy benefits like convenience and lower costs.

While gender can be a factor given the differences in men and women’s bodies, modern bikes are considered unisex. What’s more, bike fitting disparities based on gender can be fine-tuned once you’ve bought a bike with the right frame size.

For instance, you can adjust saddle height, handlebars, and stem to get the perfect size for you. Some bikes have crank arm and brake lever adjustments, among many other adjustments you may want to make. The above guide eliminates the trial and error method associated with buying bikes online.

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