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Kids Bike Sizing Guide

Introduction

Learning to ride a bike is a huge milestone in your child's life, and we're here to set them up for success. Finding the right bike size for your child is crucial. When a bike is too big or too small, it can ruin their riding experience. It's all about making sure your kid feels comfortable and safe while riding. Our sizing guide will help you find the perfect bike for your young Rider!

Fitting your child to the perfect size bike can seem a bit tricky, but it is actually easy! Finding the perfect bike fit is:

INSEAM + EXPERIENCE = MINIMUM SEAT HEIGHT

You just need to know these 2 things about your Rider:

  • RIDER INSEAM = Your child's inseam, measured from the top of the crotch directly to the ground. (This is NOT a pant leg inseam measurement).
  • RIDER EXPERIENCE = Your child's ability, comfort and confidence levels while riding a bike.

NOTE: This guide is specifically about bike sizing. Beyond fit, you'll also want to make sure you're selecting the right style of bike to meet your child's riding interests. You can learn more about picking the right style of bike with our Choosing the Best Bike for YOUR Child Guide.

How to Size Your Rider

Rider Inseam

Start by measuring your Rider's inseam, following these steps:
  1. Have your Rider stand barefoot and flat footed against a wall with their feet shoulder width apart.
  2. Place a hardbound book in between their legs and raise it to the top of the crotch (as high as it will comfortably go).
  3. Holding the book in place, have your Rider step away from the wall.
  4. Measure the distance from the top of the book directly to the floor. That is your Rider's inseam.

TIP: We recommend repeating this measurement multiple times, as it can be a bit tricky to accurately measure.

NOTE: This inseam measurement is different than a pant leg inseam measurement.

    Rider Experience

    After measuring your Rider's inseam, it is now time to understand their riding experience.

    In determining your Rider's experience, you should consider their ability, comfort and confidence levels while riding a bike. Experience is important because new riders must be able to comfortably reach the ground while straddling the bike seat in order to best learn, while experienced riders may prefer the benefits of a larger bike (even if their heels are well off the ground).

    FIRST TIME RIDER (No Balance Bike Experience)

    If Under 4 Years OldThis is a Never Ever RiderWe strongly encourage starting your young Rider on a balance bike. Learn more with our Balance Bike Guide.

    If 4+ Years Old: This is a Never Ever Rider. In order to comfortably learn, their feet should be flat on the ground while straddling the bike seat.

    If your Rider is just learning to pedal and between bike sizes, we recommend erring on the side of a smaller bike. Being able to comfortably straddle the bike is so important when first learning to pedal.

    FIRST TIME RIDER (With Balance Bike Experience)

    Timid Riders: This is a Beginner Rider. In order to comfortably learn to pedal, their feet should be close to flat on the ground while straddling the bike seat. Due to their balance bike experience, they should comfortably learn to pedal from this position.

    Confident Riders: This is an Intermediate Rider. In order to comfortably learn to pedal, their heels should be 1-2 inches off the ground (while still keeping their toes on the ground) when straddling the bike seat. Due to their balance bike experience, they should comfortably learn to pedal from this position.

    If your Rider is just learning to pedal and between bike sizes, we recommend erring on the side of a smaller bike. Being able to comfortably straddle the bike is so important when first learning to pedal.

    SECOND (+) PEDAL BIKE RIDER

    If your Rider is already pedaling (without training wheels), they should be comfortable with their heels off the ground when straddling the bike seat.

    Timid Riders: This is an Intermediate Rider. They should be comfortable with their heels 1-2 inches off the ground (while still keeping their toes on the ground) when straddling the bike seat.

    Confident Riders: This is an Experienced Rider. They should be comfortable with their heels 2-3 inches off the ground (while still keeping their toes on the ground) when straddling the bike seat.

    TIP: Experienced Rider's will get more life out of their bike by starting with their heels off further off the ground, giving them more room to grow into the bike.

    NOTE: If your Rider's only pedaling experience is with training wheels, we recommend treating them as a FIRST TIME RIDER (with Balance Bike Experience).

    Finding the Right Size Bike

    Using your Rider's Inseam and Experience, you can now determine the right size bike for your child!

    To do so, we must translate your child's inseam measurement into an appropriate seat height by adjusting for their experience:

    INSEAM + EXPERIENCE = MINIMUM SEAT HEIGHT

    Starting with their inseam measurement, add the following "Experience Adjustments" (to account for their heels off the ground while straddling the bike seat) to determine the seat height they need:

    • Never Ever: 0 inches
    • Beginner: 0-1 inch
    • Intermediate: 1-2 inches
    • Experienced: 2-3 inches

    We know you want a bike that will last your child, so you'll want to shop for bikes where the lowest (minimum) seat height is near what your child needs. This will give them plenty of room to grow with their new bike!

    Now that you know what minimum seat height your Rider needs, you can start shopping around!

    Examples

    Never Ever Rider with an inseam = 14 inches
    Age = 5 years old

    Shop for pedal bikes with min. seat height = 14 inches

    Beginner Rider with an inseam = 15 inches
    Shop for pedal bikes with min. seat height = 15-16 inches

    Intermediate Rider with an inseam = 17 inches
    Shop for pedal bikes with min. seat height = 18-19 inches

    Experienced Rider with an inseam = 21 inches
    Shop for pedal bikes with min. seat height = 23-24 inches

    3 year old Never Ever Rider with an inseam = 12 inches
    Age = 3 years old

    Shop for balance bikes with min. seat height = 12 inches

    Bike Measurements

    Bike Weight

    Making sure your child has a lightweight bike is one of the most important things you can do to set them up for success!

    We recommend finding a bike that weighs less than 1/3 of your child's weight.

    Many kids bikes sold by large retailers weigh 30+ lbs. Imagine riding a bike that weighs as much (if not more) than you! The lighter the bike, the easier it will be for your child to maneuver, and the more they'll enjoy riding!  

    TIP: Keeping the bike lightweight is particularly important when a child is first learning how to pedal (although this of course varies by child and how you are planning to use the bike).

    Our Bike Measurements

    At Ready Set Pedal we standardize measurements across all brands to make sure you're comparing apples to apples (not apples to oranges or pineapples!). Our standardized bike measurements are:

    Ready Set Pedal Bike Measurements

    Seat Height: Measured from the top of the seat to the ground. This measurement is typically taken near the center of the seat. It is taken with the seat in both its lowest and highest position.

    Standover Height: Measured from the top of the top tube to the ground, passing directly by the front of the chainring.

    Brand-Specific Bike Measurements

    Most brands provide brand-specific sizing guides to help find the right size bike for your child. These recommendations can be helpful, but it's not always clear where they come from. For example, if a brand provides a "Standover Height," you don't necessarily know where that measurement was taken for that specific bike. (Does it refer to the saddle or top tube? Where on the top tube?) Additionally, it's not always easy to compare across brands using these measurements. (How does a bike that fits a child 45 inches tall compare to a bike with a standover height of 18 inches?)

    Our recommendation is to always start with our INSEAM + EXPERIENCE = SEAT HEIGHT approach. Once you have this baseline, you can layer in brand-specific recommendations as your research specific bikes.

    FAQs

    Is Fit/Size the Most Important Factor when Picking a New Bike?

    Coming soon!

    Should I Rely on My Child's Age or Height to Pick the Right Bike Size?

    We include age and height recommendations on most bikes for a general reference point. However, because children can vary so much in size, and inseams can vary so much with height, we highly recommend using INSEAM + EXPERIENCE = SEAT HEIGHT approach for the most reliable sizing.

    Should I Rely on a Bike's Wheel Size to Find the Best Fit?

    We include size recommendations by wheel size on most bikes for a general reference point. However, because bike designs and geometry can vary so much within the same wheel size, we highly recommend using INSEAM + EXPERIENCE = SEAT HEIGHT approach for the most reliable sizing.

    Does Standover Height Matter?

    Coming soon!

    Why Isn't My Child's Leg Fully Extending While Pedaling?

    Coming soon!

    Picking the Right Style of Bike

    This above guide is specifically about bike sizing. Beyond fit, you'll also want to make sure you're selecting the right style of bike to meet your child's riding interests. Important factors to consider include:

    • Bike Type (hybrid, mountain, road, etc.)
    • Bike Brakes (hand, coaster, disc, etc.)
    • Bike Geometry (wheel base, seating position, etc.)
    • Bike Specs & Components (gears, tires, etc.)

    You can learn more about picking the right style of bike with our Choosing the Best Bike for YOUR Child Guide.

    Any Questions About Bike Fit?

    Please contact us if there's anything we do to help you find the perfect bike fit for your Rider!

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