When choosing a new bike, bike fit is undoubtedly the most important consideration. If the bike is too small, you will feel awkward and unable to stretch. If it’s too big, even reaching the handlebars can be challenging.

        Although cycling is a healthy sport, there are also many potential safety hazards, such as choosing the wrong size of the bicycle and hurting yourself for a long time. Yet most consumers don’t need shop experts to help them choose the right bike size when shopping for a new car. If you don’t know enough about the new car you want to buy, you’re not alone, because that’s the case with most people, and many people are reluctant to buy a new car online because they can’t test it out in person.

        Before you buy a bike, you need to measure some body size data. Bike dimensions are based on a person’s height and build, not weight. You’ll want to know your height, span height, torso length, and arm length — the basics. Be sure to take off your shoes before taking these measurements. With the help of a good cyclist and a soft tape measure, the measuring process is easier.

In this quick guide, we’ll guide you on how to measure so you can shop online with confidence.

Principles of choosing bicycle size

        While many bikes come in familiar sizes like S, M, L or XL, some don’t. These bikes are offered in inches or centimeters as a size unit (eg 18 inches or 58 centimeters).

 Frame size refers to the length of the frame’s riser tube. There are two methods of this measurement.

 “C-T” measures the length from the center of the BB bottom bracket to the end of the frame riser.

 “C-C” measures the vertical distance from the center of the BB bottom bracket to the center of the frame’s upper tube.

        There is currently no industry standard for collecting bike sizing or rider fitting, and most brands measure bike sizes slightly differently. Women and children (especially young girls) have shorter arms and longer legs than male cyclists. This means their suitability on bikes is slightly different, especially on road bikes. A simple rule of thumb for female riders and children is that if you are torn between two bike sizes, choose the smaller one. Smaller bikes are easier to control, and the seat height can easily be increased.

        Still, each bike brand should offer some specs based on its own measurements. To find a size chart, check out the brand’s website for their preferred standard.

 How to measure your bike size

       No matter what type of bike you want, pay attention to choosing the right frame size for your body. This is important, not only from a comfort factor, but also from a safety standpoint. In simple terms, for beginners, all you need is a soft tape measure to measure your bike. These measurements will help you find a frame size that works for you.

 If you want an exact size that fits you, you should go to your local bike shop first.

 Which size do I need?

       Learning how to measure a bike is half the job. You also need to measure three metrics to find the right bike size for your anatomy.

       Height: This is a critical first step. Most manufacturers have bike size charts that show the size of the bike for the rider’s height. Height alone doesn’t guarantee  a perfect fit, so we recommend taking the next two measurements as well.

       Inseam Length (Span Height): Stand with feet about 6 inches (15 cm) apart, as you would when riding a bike. Measure the length from the crotch to the soles of the feet. When using this method, it is easiest to have someone else measure with you. If you’re alone, use a hardcover book to help you measure: Wear cycling shoes and stand upright against a wall; sit astride the book and straighten your back; use a pencil to mark where the spine of the book meets the wall. Then, you can step away from the wall and measure the length of the mark to the floor. For accuracy, be sure to measure several times.

       Ideal seat height: For a safe ride, you need some clearance between your crotch and the top tube (for road/commuter/gravel bikes, about three fingers wide). For road bikes, the recommended minimum clearance is 2 inches (5 cm).

       For mountain bikes, you can get extra room with at least 4-5 inches (10-12.5 cm) of clearance. This helps avoid injury if you need to brake suddenly or jump out of your seat!

       First you need to determine the seat height, if it is a road bike, multiply your inseam length (span height) by 0.67. For mountain bikes, multiply the inseam by 0.59. Another measurement, standing height, will also be taken into account to find the correct bike size – see below.

Bike model and size

      Road bikes are more difficult than other bikes to choose exactly to fit sizing and require more measurements to hone the fit. In addition to the seat height stats, you also need to have enough horizontal length—often referred to as “Reach”—the position on a road bike that your feet rest on the pedals to allow you to stretch forward comfortably. The good news is that if you’ve found the right frame, you can fine-tune components like seat position (front to rear) and stem length for optimal ride comfort.

      Once you have a frame you like, you should also take it to your local bike shop. There, a professional mechanic at the shop can help you make some adjustments and replace some parts that don’t fit you (eg stem, handlebar, seatpost, etc.). Meanwhile, standing height is the most important thing when sizing a mountain bike or commuter bike. The stand-up height of the bike rack, or the distance from the center of the top tube to the ground, should be a little 2-5 inches less than your stride height, depending on the type of bike. MTB enthusiasts need 4-5 inches of clearance, while road bikes and commuters only need about 2 inches of clearance.

How to choose the right bike for you

     Different types of bikes have their own advantages and disadvantages, but there is no best or worst. The right bike is one that you find comfortable, functional, and enjoyable to ride.

      Choosing the right bike is a personal decision, so be sure to do your homework and have a realistic budget in mind. Bike prices have definitely risen in recent years, exacerbated by soaring bike popularity during the Covid-19 pandemic.

       The hardest part of the process is deciding which type of bike to buy. Once you’ve identified the type of bike that suits your needs, it’s time to focus on key metrics like fit, function, and comfort.