Bicycle Sizing

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Bicycle Sizing

Do you know the right bike size for you? No? Help is here. Bicycle sizing is an essential factor when buying a new bike because it will determine your comfort as you ride the bike. Don’t worry, mountain bike sizing is not rocket science – just a few easy pointers, and you are good to go!

Did you know...?

Bicycle Sizing

Did you know that riding a bicycle of the wrong size can compromise your health and performance?

For example, riding a bicycle that is too big for you will cause muscle and joint aches as you strain to grip the handlebars and touch the pedals. Riding a bicycle that is too small for you will compromise your ability to pedal with long, powerful strokes.

In short, bicycle sizing is ultra-important. Don't neglect it.

Bicycle Sizing Methods

There are several methods to determine the right bicycle sizing. Let's take a look at some of these methods, but first, let's clear up one term: "Inseam".

"Inseam" is a term used both for tailoring and for selecting the right bicycle size. In the world of bicycle sizing, it is the distance from the bottom of the crotch to the lower ankle.

Method 1: The Simplified Bicycle Sizing Guide

  • Stand over the frame (with bike riding shoes on) with both feet on the ground
  • The height of the bicycle top tube should be below your crotch by the following measurements:

Bicycle Crotch to top tube height
Racing, touring or hybrid bike About 1"
Mountain bike About 2"

Method 2: Bicycle Frame Size (= Seat Tube Length)

The frame size (this is the length of the seat tube) = inseam x (0.65 to 0.67)

Note: You can also use a bicycle sizing chart to calculate the right frame size.

Method 3: Top Tube to Bottom Bracket

The distance from the top tube to the bottom bracket

  • Road bikes: inseam x 0.67
  • Mountain bikes: inseam x 0.67 - (4" to 5")

Method 4: Seat to Bottom Bracket

The distance from the seat to the bottom bracket = inseam x 0.88

Method 5: The Knee Position

Note: This method can serve only as a rough guide to the right bicycle frame size.

  1. Sit on your bike.
  2. Adjust the seat height so that you feel comfortable.
  3. Place the center of each foot above the center of the pedal.
  4. Rotate the pedals so that both are at the same height.

Your forward knee should be just above the center of the front pedal, that is on the same horizontal plane.

Did you know...?

Did you know that bicycle frames made specifically for women usually have shorter top tubes?

This is because women are genetically predisposed towards shorter torsos. If you're female and have had trouble finding a bike frame that fits your size, you might want to look into bicycles with frames designed specifically for your gender!

Tips For a Better Bicycle Sizing

Bicycle Frame Size

Having the right bicycle frame size is the most important factor when buying new bicycles. A bicycle with a frame size that is too small or too large is uncomfortable to ride.

Rule Of Thumb - One of the quickest ways to check the frame size is to stand over your bike with both feet on the ground. The ideal distance should be an inch or so from the frame to your crotch.

The Complete Guide - For a complete guide on selecting the right bicycle, you are invited to visit my page about how to choose the right bicycle frame size.

Mountain Bike Sizing

For mountain bike sizing you can use sizing charts. This will give you an idea of the exact frame size that your bike should have.

Rule Of Thumb - Sizing charts are based on the distance between the top of the seat tube and the middle of the bracket at the bottom. For mountain bike sizing, a bike frame of 3.9" to 4.7" (10 to 12 cm) is required.

The Complete Guide - For a complete guide on selecting the right mountain bike, you are invited to visit my page about mountain bike sizing.

Road Bike Sizing

Road bikes are always around 10 centimeters higher on the frame size than the mountain bike sizing, so just use that same scale and add 10 centimeters to the frame size depending on your height.

BMX Bike Sizing

I'm afraid that for BMX there's not much to choose from since pretty much all BMX bikes come with the same geometry, 10-20mm Bottom Bracket height, around 71°-74° head angle, 15-inch chainstay. They are all made for one specific thing.

Kids Bicycle Sizing

Kids need to have the correct bike size at all times so that they can ride safely.

If you buy a bicycle for your kids, do not buy a bicycle that they would grow into. That might lead to accidents.

Bicycle Sizing Calculator

I can recommend this bicycle size calculator, containing:

Bicycle Frame Size Calculator

Bicycle Saddle Height Calculator

Bike Measurement Tool

Measuring a Road Bike

Measuring a Mountain Bike

Measuring a BMX Bike

How to Measure a Kids Bike

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