Kids’ bikes are all about having fun, making memories, and giving your child the kind of freedom only found on two wheels. Whether your lil' rider is ready for their first bike ever or a bigger size, we’re here to help.
In this guide, we’ll cover:
Trek kids’ bike buyer’s guide
What are the best bike sizes for kids?
The right bike size depends on your child’s age and height — just don’t size up thinking they’ll grow into it. A bike that’s too big can slow learning and hurt confidence, while the right fit helps kids feel comfortable and build skills faster.
Kids’ hybrid bikes
These bikes are awesome for all-around riding. They are designed for comfort and confidence on every ride, whether on roads, light gravel paths, or even detours through the lawn. They're typically equipped with tires designed for traction on a variety of surfaces.
See kids’ hybrid bikesKids’ mountain bikes
Some kids’ bikes have rugged styling but are still meant to be ridden on pavement. True youth mountain bikes are built specifically for off-road riding. They have parts designed to handle bumps, rocks, and dirt — like knobby tires and suspension forks.
See kids’ mountain bikesKids' bikes are measured by wheel size
Adult bikes are measured by frame size, but kids’ bikes are measured by wheel diameter. Sizes range from 12" to 26".
Age and height help determine a size bracket
Your child’s age and height will help guide you to the right wheel size. Measure your child, then check out the sizing guidelines below to find their wheel size.
Inseam helps find the best fit
Once you have an idea of wheel size, consider measuring your child’s inseam, too. Knowing this will help you find a bike that’s comfortable for them to hop on and off.
Kids’ bike size chart
Size brackets are wide and tend to overlap, plus all bikes fit differently (even if they’re the same wheel size), so head down to your local bike shop with your child for some fun test rides!
Pro tip: If your child is older than 12 and/or taller than 4’ 8" you can start looking at adult bikes.
Bikes for 13+ year olds
A lot of older, taller kids can fit on the smallest adult bikes. When you go looking for an adult bike, remember that they are sold by frame size and not wheel size!
Shop bikesHow should a kids’ bike fit?
A bike that fits well is easier for learning to ride, and ultimately more enjoyable for your child from day one. Below are some visual fit cues that’ll help you decide whether or not a bike fits your child properly.
Seat height
It’s important to have your child’s seat set at the right height. Generally, for balance bikes and for their first non-training wheel bike, your child’s feet should be flat on the ground while they’re seated. For training wheel bikes and kids comfortable on pedal bikes, only their toes should touch the ground.
Knee position
Knee position is directly related to seat height. When kids are just learning, they should have more bend in their knees so they can easily put their feet on the ground. As they feel more comfortable, you can raise the seat up so they can get full leg extension for better pedaling.
Standover height
You’ll want to make sure your child can easily stand over the bike with their feet on the ground, and with an inch or two between them and the top tube of the bike. This helps them feel confident stopping and getting on and off the bike.
Foot position
When kids are starting to learn on a balance bike, their feet need to touch the ground so they can propel the bike. For training wheel bikes or pedal bikes, your child will be most comfortable with the ball of their foot resting flat on the pedal.
Frequently asked kids’ bike questions
What’s the best kids’ bike?
There are lots of kids’ bikes to choose from, so narrowing down your options can be hard! The main thing is to ensure the purpose and features of the bike match your child’s skill level. For example, most young kids will likely only ride short distances. They benefit from a simple, hybrid-style bike without unnecessary features. As kids get older and gain more skills, they’ll be able to choose from bikes with more features.
Pro tip: Girls’ bikes and boys’ bikes are essentially the same, they just might have different colors or graphics.
What's with these different kids’ bike brakes?
As kids gain riding skills, the bikes available to them will have more brake options. You want to start them off with no brakes (balance bikes) or a coaster brake (the kind of braking that engages when you pedal backwards) because it’s intuitive to put your feet down or pedal backwards to stop. Once they are comfortable stopping themselves using these brakes, and have more developed muscles in their hands, they can upgrade to hand brakes. Some kids’ bikes even have coaster brakes and hand brakes so kids can start getting comfortable with them sooner.
Should a kids' bike have gears?
Not at first! It’s more important that kids learn how to balance and pedal properly. This is why beginner bikes typically have just one gear. As they gain bike handling skills, confidence, and hand strength, you can upgrade them to a kids’ bike with a few gears. This will help them get comfortable with shifting, which they’ll of course need to know how to do as they continue to ride more complicated bikes.
Want a kids’ bikes with training wheels?
Training wheels are a great way to get kids comfortable riding. They’re a good choice for kids who are too big for a balance bike or simply need a bit more time to gain confidence.
Pro tip: When teaching your child to ride, remember that the emphasis should be on balance, not pedaling. As soon as your child is comfortable with removing their training wheels, it’s time for them to roll!
What accessories are essential?
Definitely a helmet! It’s important for your kid’s on-bike safety, and it teaches them that riding safer matters. We also recommend front and rear lights on every ride to help them stand out, and you can add fun stuff like baskets and handlebar bags.
We want your kids to enjoy cycling just as much as you do, so we put the same amount of dedication and know-how into their bikes as we do yours. Each one of our kids’ bikes are made with:
• Durable, high-quality materials and assembled by a professional mechanic
• Smaller diameter grips for better control
• Reliable alloy linear pull brakes for quick adjustments
• Smaller 51mm cranks optimized for kids
• Easy add kick stands
• Easily adjustable seats to grow with your kid
Plus, all Trek stores offer a kids’ trade up program. So, when your little one hits a growth spurt, their bike can grow with them at less cost to you.
More helpful programs
Love it or we will take it back
Learn about our 30-Day GuaranteeNICA youth league
Learn more about youth mountain bikingGreat rides near you
Find family routesKids' trade-up program
Learn moreAlready know which bike is right for your kiddo?
Shop online and get it shipped right to your doorstep, then we'll walk you through the final assembly below.
