How To Find The Right Size Of A Mountain Bike Frame

There are many factors to consider when purchasing a mountain bike, and making sure you get the right size of frame is the most important. The type of riding you do, your body measurements and your fit preferences all need to be considered when choosing the size of your bike. Ultimately, this will ensure your comfort, safety and performance when riding off-road. There are four easy steps to help you find the right size of mountain bike frame.

Step 1

Understand the different mountain bike sizes. Frames are generally measured in inches, from the center of the crank to the top tube where the seat post begins. This measurement corresponds to your inseam, so know your measurement before shopping. To do so, use a tape measure and measure the distance from your crotch to the ground. Record this number in inches and take it with you when shopping.

Step 2

Check the clearance. Once you have a mountain bike that fits your inseam and interests, do a straddle test. Put one leg over the bike and straddle it with both feet resting flat on the ground. To avoid personal injury, you want to be sure to have 2 to 5 inches of clearance between the top tube and your crotch. Make sure you are wearing your mountain bike shoes when doing this because they count toward your overall leg length.

Step 3

Sit on the seat with your feet on the pedals. This will help you test your seat height and leg extension. Your seat should be high enough so you only have a slight bend in your knees when your legs are fully extended toward the ground. If you are using clipless pedals or cages on your pedals, test your seat height with these in place. Seat heights can be adjusted, so this generally does not make a difference in the frame size you choose, but it is important in the overall fit.

Step 4

Test the mountain bike thoroughly before purchasing it. You should feel in control and have full range of motion with your legs. You also want to make sure you can easily reach the gear adjustments and brakes. Ask the salesperson to make adjustments accordingly. Comfort and ease of movement when riding on trails and navigating uneven terrain are extremely important.

Tips and Warnings

Here is a convenient sizing chart from Mountain Bike World to help you determine the best bike size: XS 14"-15" S 16"-17" M 18"-19" L 20"-21" XL 22"-23"