How To Measure A Bike

Are you trying to put your bike on the market but have no idea how big it is? Knowing your bike’s dimensions is important for listing it on an online marketplace or if you are looking for a new bike that is the same size. Or maybe you need to know if you can fit it in your car for next week’s road trip! Regardless of the reason, here’s the best way to measure your bike…

Bicycle Frame Sizes

A bicycle’s size refers to its frame size. Bikes come in different sizes to better suit different body types. Frame sizes can range anywhere from 18″ to 25.5″ (46 to 64 cm). Choosing a bike frame that is correct for your height will allow for maximum comfort and safety while riding.

Bikes will sometimes be listed as small, medium, or large.

In this case, small bikes are for those under 5’4″ (164cm). These frames will be between 18″ and 20.5″.

Medium bikes measure 20.5″ to 22″ and are meant for people between 5’5″ and 5’9″.

People who are 5’10” (178cm) are taller will want to buy a large bike, whose frame will range from 23″ to 25.5″.

Bike Sizing

Click here to calculate what size bike is best for you.

Parts Of Your Bike

To measure your bike frame, you must first locate the different parts of your bike.
Bike Frame Parts
Top Tube: This tube is located between the handlebars and seat of your bike. It affects how you can reach the handles while sitting on the bike.

Seat Tube: The seat tube bridges the gap between your seat and your pedals. It is measured to the center of the crankshaft, which is the mechanism the pedals are attached to.

Head Tube: The head tube is found between your handle bars and front wheel. It is measured until the point where the forks attach to the wheel.

How To Measure Your Bike Frame

Bikes are most commonly measured by their seat tube length. There are two different methods of measuring the seat tube.

Center-to-Top method begins with the section where the seat post enters the seat tube, and ends at the base. The base is round part at the bottom, which holds the axle.

Center-to-Center method is common among European manufacturers, and involves measuring from the center of the top tube to the center of the seat tube.

Another way to measure your bike is by the top tube. To find the length of the top tube, begin with the center of the seat tube and end at the center of the head tube.

The video below clearly goes through the required steps you need to take:

Measure Your Inseam

The best way to determine which bike size is best for you is by measuring your inseam. Because you should be able to stand comfortable straddling your bike, your inseam measurement will determine how tall your bike can be.

With a tape measure, either measure a pair of pants that fits you well, or your body. Start from the crotch and extend the tape measure all the way down to the inside of your foot. This is your inseam.

Once you have your inseam measurement you will need to do some simple math to determine the correct bike size. Once you have measured your inseam, multiply it by .67. The resulting number is the height you should look for in a seat tube. To find the estimated length of the top tube, subtract 4″ from this result.

Bicycle Wheel Sizes

Bike Wheel Sizes

Bike wheels typically come in three sizes.

26″ is the most common wheel size, often found on road bikes.

27.5″ is most typically found on older bikes and on hybrid bikes. This size can also be referred to as 650B.

29″ or 700c are heavy-duty wheels often found on mountain bikes.

How To Measure Your Bike Wheels

Bike Tire Size

If your bike has tires on it, you shouldn’t have to measure the wheels. The wheel measurement is listed on the side of the tire with the diameter first and the width following it.

If you can’t find the tire size listed or you don’t currently have tires, it’s not too hard to measure them yourself.

You can measure the diameter by stretching a tape measure from one end of the wheel straight across to the other, making sure to get the largest measurement you can find. This will tell  you the tire size you need to purchase.

You can also measure the circumference by wrapping the tape measure around the bead seat (the outside of the rim, where the tire rests).  After measuring the circumference, convert it to millimeters. 1756mm is a 26″ tire, 1979mm is a 27″ tire, and 1954mm is a 29″. Find a more in-depth list of wheel measurements here.

Now that you know how to measure your bike, maybe you’re in search for a new bike to replace your old one. If so, you can check out our review of the 12 hybrid bicycles we think are the best on the market right now to see if you can find something that suits your needs!

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