Kid's Bike Sizing Guide

Kid's Bike Sizing Guide

Choosing the correct size of bike for your child as they grow is essential so they feel comfortable and so that they are operating the bike most efficiently and safely when riding. Along with choosing the correctly sized bicycle, having it set up right will also make the bike easier for them to handle. For the purpose of this guide we have decided to include some of the information from the buying guide as children grow at such different rates it would be a very approximate guide without some information surrounding why you may choose one type of kids bike over another. As a starter bike you could easily buy a Balance Bike or a 12" Wheel Stabiliser Bike but the reasons for buying each one would be different.

Balance Bikes:

2-4 years of age: Balance Bike (one size)

    Balance bikes are a relatively new product to the cycle market and have really taken off over the last 3 years. Balance bikes provide a great platform for your child to learn to ride a bike in a fun and safe way. As the bike comes without pedals it is propelled and stopped by your child's feet, as such riding a balance bike will teach your child the core fundamentals of balance, coordination and steering control. Balance bikes can also help your child 'skip' the stabiliser stage when they move to a larger bike. A bike equipped with stabiliser wheels does not require your child to actively balance where as a balance bike does from the outset. Balance bikes have been designed to function without pedals, brakes or the drive chain system and are very simple in design. The lack of moving drivetrain components means that there is minimal chance of your child being tangled up in the bike or hurt by sharp objects and they are great fun!

Stabiliser Bikes:

  • 2 - 4 years of age (2' 10" - 3' 02"): 12 inch wheel bikes
  • 3 - 5 years of age (3' 01" - 3' 05"): 14 inch wheel bikes
  • 4 - 6 years of age (3' 05" - 3' 08"): 16 inch wheel bikes
  • 5 - 7 years of age (3' 08" - 4' 00"): 18 inch wheel bikes

Children's bikes in 12" - 18" wheel size's see your child transitioning from a balance 'play' bike to a bike with bigger wheels, pedals, brakes and a single speed drivetrain. One of the key design factors for this age range is ensuring that the bike is both durable and lightweight as it needs to withstand the youthful exuberance of 2-7 year olds. Stabilisers come fitted to 95% of bikes with 12 - 18" wheels and can be removed if your child does not required them. These bikes often come with higher rise handle bars so the child can sit upright providing a good view of whats going on in front of them aiding control. Front and rear brakes will be fitted to all bikes in this category and they will come with flat grippy pedals to ensure that your child is well supported and weight is centred over the bottom bracket for ease of pedalling.

This size of bike is designed with a low stand over height, this means that in the event of a crash or a dismount there is less chance of your child being tangled up in the bike. The lower stand over height also makes it easier for your child to mount and dismount the bike.

Non Stabiliser Bikes:

    20 and 24 inch wheel bikes signify a transition onto more functional and better equipped cycles with geared drivetrains, stronger frames, bigger wheels. On mountain type children's bikes knobby tyres and suspension now make an appearance. These are the first wheel size's where you can buy a "Road Bike" for your child. You could also consider buying a BMX type bike for your child if they are interested in something more robust that they can do tricks and stunts on. BMX bikes are far more robust than other types of bikes and can withstand being dropped and thrown about far more than a conventional mountain type kids bike.

Mountain Bikes:

  • 6 - 10 years of age (4' 00" - 4' 05"): 20 inch wheel bikes
  • 8 - 12 years of age (4' 05" - 4' 09"): 24 inch wheel bikes
  • 20" wheel mountain bikes usually come with front suspension for control, stability and comfort. Some 20" wheel bikes have front and rear suspension however this is often overkill and provided at the expense of lightweight. 20" wheel mountain bikes have gears at the rear of the bike only, due to space constraints at the front because of the smaller frame size. Speed is managed by powerful and easy to pull brakes. Flat pedals on 20" wheel junior bikes come with a larger profile to accommodate a larger shoe size. This provides more stability and support.
  • 24" wheel mountain bikes usually come with front suspension for control, stability and comfort. Some 24" wheel bikes have front and rear suspension however this is often overkill and provided at the expense of lightweight. 24" wheel mountain bikes come with gears at the front and rear of the bike providing a greater spread and further increasing the usefulness of the bike. Speed is managed by powerful and easy to pull brakes. Flat pedals on 24" wheel junior bikes come with a larger profile to accommodate a larger shoe size. This provides more stability and support.

Road Bikes:

  • 6 - 10 years of age (4' 00" - 4' 05"): 20 inch wheel bikes
  • 8 - 12 years of age (4' 05" - 4' 09"): 24 inch wheel bikes
  • 20" wheel road bikes are very much a shrunk down version of an adult size road bike. 20" wheel road bikes have gears at the rear of the bike only, due to space constraints at the front because of the smaller frame size. Children's road bikes are lighter and faster than their mountain bike equivalents. If your child is showing interest in the sport of cycling (maybe they are a budding Bradley Wiggins or Laura Trott!) then maybe it would be a good idea to consider a road bike. Speed on a child's road bike is managed by powerful caliper type brakes. Flat pedals are provided for safety.
  • 24" wheel road bikes are very much a shrunk down version of an adult size road bike. 24" wheel road bikes come with gears at the front and rear of the bike providing a greater spread and further increasing the usefulness of the bike. Children's road bikes are lighter and faster than their mountain bike equivalents. If your child is showing interest in the sport of cycling (maybe they are a budding Bradley Wiggins or Laura Trott!) then maybe it would be a good idea to consider a road bike. Speed on road bikes is managed by powerful caliper type brakes. Flat pedals are provided for safety.

BMX Type Bikes:

  • 6 - 10 years of age: 16 inch wheel BMX type bikes
  • 7 - 11 years of age: 18 inch wheel BMX type bikes
  • 10 + years of age: 20 inch wheel BMX type bikes

BMX Bikes are compact heavy-duty stunt bikes that come with 16", 18" or 20" wheels and wide tires. The bike design has an upright handlebar position with a steep head angle for quick steering. The small nature of the bike makes it very agile and is ideal for jumping, tricks and stunts. A BMX bike is equipped with a single gear is most often used in a skate park or street environment. BMX bikes are very fashionable and popular at the moment. They should not be considered as a bike for long distance riding.

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