How to Measure Road Bike Frame Size

Measuring bike frame is critical for balancing and smooth riding experience. It’s more important when you’re making an expensive purchase for yourself, or for someone else. You have to look into many factors before finalizing a particular model. You need to measure the frame size of the bike at a certain part, and different bike types have different frame sizes, so you need to be sure about it.

Why measurement is so important? It’s simply to avoid the following:

• Getting an improper road bike.
• Having a bad posture that not only increases discomfort, but you also have a chance to fall badly.
• Improper body posture puts unnecessary pressure on muscles causing pains.

So, follow this guide to get the right-fit bike for you.

How to Know Road Bike Frame Size

Road bikes are available in the market in several different styles, sizes and designs.

• Road bike frames are constructed with steel, carbon or aluminum.
• Road bike tires also come in different sizes, such as 700c, 26 inches and 271/4 inches

Before you learn how to measure road bike frame size, you need to determine what type of road bike you’ll buy.

1. Classic Road Bike

These road bikes are found everywhere from road trips to triathlons. Classic road bike features a top tube (attaching the fork and the seat tube) that goes parallel to the road surface. The road paralleled position of the top tube provides stability and support to the frame.

2. Compact Road Bike

Compact road bikes are getting increasingly popular among commuter, urban and city style bikes. These road bikes are not much different than the classic version, except for the fact that their top tube slopes upward starting from the seat tube towards the head tube. This sloping offers better leg clearance and makes it easier for the riders to find the right fit.

3. Mixte Road Bike

This road bike type is quite different from the other two. It features a step-through frame having 2 tubes sloping downward from the head tube and running full length across the bike frame to the rear axle.

This particular design offers strength and sturdiness to the frame, especially the lower part of it. It also makes riding and balancing easier for starters who are willing to lose weight.

Good thing is, all these frames are measured the same way!

Road Bike: How to Measure

There are two major factors in choosing the right frame size:

• The height of the rider
• The leg length

Step 1: Measure the road bike frame

1. Locate the top of the seat tube. This is the point where seat post is held by the seat clamp.
2. Now, locate the center of the bracket where crank arms are held together (the front axle).
3. Measure C-T: it is the vertical distance from the top of the seat tube to the bottom bracket.
4. Note down the measurement in centimeter and inches. Keep in mind that the road bikes are normally measure in centimeters, so if you’ve recorded your length in inches, round it to the nearest half-inch.

After measuring the frame size, you can compare it with your height and leg length.

Step 2: Measure your height

The frame size gives you an idea about the height range. Do you know for a 56 cm road bike frame, how tall a rider should be? He should be between 171 cm (5’7”) and 181 cm (5’11½“).

Step 3: Measure the leg length

If you think, standing comfortably with the top tube of the road bike between your legs is the right way to size the frame, you may end up getting something uncomfortable. You need to know your leg length.

The leg length is the distance your crotch and the floor. Professionals call it bicycling inseam. Compared with the height, leg length measurement gives more accurate picture as to which frame size suits the rider.

Measuring leg length is quite easy but you’ll need a person to measure it for you. Follow these steps:

1. Take off your shoes and stand upright, with your feet apart (shoulder width). Your back should be against the wall, for accurate result.
2. Take a large book and place it between your legs in such a way that the spine should be firmly in contact with your crotch.
3. Your helper will measure the distance from the spine of the book to the floor.
4. Note down the length and compare it with the rider’s chart.

Buying Online?

People prefer to buy road bikes online to avoid extra cost. But they might make a blunder if they don’t know the proper frame size. If you’re an online buyer, follow these steps:

1. Measure your height and leg length beforehand.
2. Enter the measurements (in inches or centimeters) in this size calculator and press “calculate”.
3. Note down the road bike frame size.