How to Determine Bike Frame Size

How to Determine Bike Frame Size
Just as important as wearing the proper size shoe, choosing the correct bike frame size can make your daily rides efficient and enjoyable or arduous and intolerable. There are several ways to determine the proper frame size for your height and body dimensions. Here's how to make sure you're buying a bicycle with the appropriate frame size.
 

Instructions

Difficulty: Moderately Easy

Step 1
Strand with your legs on either side of the top tube. There should be 1 to 2 inches between the bottom of your crotch and the top tube. This is a very rough estimate of the proper frame size. There are better and more accurate methods to use.
Step 2
Stand with your back against a wall. Slide a book between your legs until the top edge of the book is against the bottom of your pubic bone. Make a mark on the wall along the top edge of where the book touches the wall. This is your "inseam" measurement. Repeat the process several times to ensure its accuracy.
Step 3
Measure the distance between the top of the seat tube and the center of the bottom bracket. This is called the "center to top" method of measuring a bicycle frame. Multiply the distance by .65 and divide the result by 2.54 to convert centimeters to inches. This is the size frame you should buy. Example: 90cm inseam x .65 = 58.5 divided by 2.54 = 23-inch frame size.
Step 4
Measure the distance between the center of the top tube and the center of the bottom bracket. This is called the "center to center" method of measuring a bicycle frame. Multiply the distance by .67 and divide the result by 2.54 to convert centimeters to inches. Example: 90cm inseam x .67 = 60.3 divided by 2.54 = 23.7-inch frame size.
Step 5
Mount a bike with the suggested frame size and take it out for a spin. Riding bikes with a series of different frame sizes is the best way to determine which frame size is right for you.
 

Tips & Warnings

 
Use measurements as a guideline, not an absolute measurement. Always test ride a bike before you buy it.
 
Use measurements as a guideline, not an absolute measurement.
 
Always test ride a bike before you buy it.
 
Avoid choosing a frame size that is either too large or too small for your body. Buy your bike from a dealer that will let you exchange the frame, if necessary.
 
Avoid choosing a frame size that is either too large or too small for your body.
 
Buy your bike from a dealer that will let you exchange the frame, if necessary.

Article Written By Allen Smith

Allen Smith is an award-winning freelance writer living in Vail, Colo. He writes about health, fitness and outdoor sports. Smith has a master's degree in exercise physiology and an exercise specialist certification with the American College of Sports Medicine at San Diego State University.

Don't Miss a Thing!

All our latest outdoor content delivered to your inbox once a week.

FREE UPDATES

Subscribe

We promise to keep your email address safe and secure.