How To Choose A Kids Mountain Bike – Tips For Buying The Right Kids Bike

From balance bikes to proper mini super bikes, kids’ bikes have come a long long way. With so many options out there, in this article i’ll try and help you navigate that minefield so you end up with the right bike for your little person.

The fitment, comfort and usability of the bike will make a big difference in how capable it is on proper terrain but also it’ll make a massive difference to how much the kids actually enjoy riding them

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Kids’ bikes these days are so good, it makes me seethe with jealousy. Back in my day, you road a heavy BMX, with brakes that didn’t work and that was that. Nowadays getting the right kids’ bike is more important than getting the right one for a grown-up.

Also if you’re reading this article you’re probably into riding bikes yourself, so you want the kids to ride it, love it, and get hooked.

For this article I’ve used Commencal bikes as my example to enable me to talk you through the ins and outs when buying a mountain bike, what you can get and what you need to consider.

Fun First
Bike Types
Things To Look For
Kids Components
Balance Bikes
Starter Bikes
Kids’ Mountain Bikes
Junior Mountain Bikes
Full Suspension

In a hurry? If you don’t have much time use the links below to quickly find the best kids bikes discussed in this article. You can be assured we only choose the best products…
Balance Bike – 
Starter Bike –
Kids Mountain Bike – 
Junior Mountain Bike – 
Full Suspension Bike – 

Fun First

Before we get into the sizing, the features and much much more, the first thing to remember, is that riding a bike should be fun.

The bikes shouldn’t be a struggle to ride. They shouldn’t be heavy, ill-fitting, too big, have adult-size components or even heavy gearing on them. If they are, it could mean that your kids aren’t going to enjoy riding them as much as they otherwise would.


Contrary to what many people believe, age doesn’t determine size of bike, height does. Just like it does for you and me and most kids’ bike brands will help you navigate their range based on height rather than age.

Getting the right sized bike for your child is really important so your child can ride confidently and comfortably. It’s important to be able to get both feet on the ground so that kids can develop their skills quickly and have a lot of fun.

We previously wrote an article on ‘What Size Bike Does a Child Need’ which includes a helpful sizing chart. You can view this article here.

Here’s how you can measure up, get your child standing in their socks against the wall with their back straight and their heels on the ground. Put a book on their head so it touches the wall. Mark with a pencil where the bottom of the book touches the wall.

Measure from the floor up to the mark then match their height with the manufacturer’s recommended sizes on their website to make sure they’re safe and comfortable.

Some brands also use the inside leg measurement to help size your kid’s bike correctly. Again, get your child to stand in their socks against the wall with their back straight. Place a book between their legs as if they were sat on a saddle.

Move your child away from the wall and measure from the floor to the top of the book. Below is the size comparison charts we’ve created to help.

Kids Height Comparison Chart

Kids Height
(Feet & Inches)
Kids Height
2’9″-3’1″85-90 cm10 inches
3′.1″-3′.3″90-100 cm12 inches
3′.3″-3′.7″100-110 cm14 inches
3′.7″-3′.8″110-115 cm16 inches
3′.8″-4′.0″115-120 cm18 inches
4′.0″-4′.5″120-135 cm20 inches
4′.5″-4′.9″135-145 cm24 inches
5′.0″ or above145 cm or above26 inches

Kids Inseam Comparison Chart

Kids Inseam
Kids Inseam
12″-14″30-35 cm10 inches
14″-17″35-42 cm12 inches
16″-20″40-50 cm14 inches
18″-22″45-55 cm16 inches
20″-24″50-60 cm18 inches
22″-25″55-63 cm20 inches
24″-28″60-72 cm24 inches
28″ or above72 cm or above26 inches

It can be really tempting to buy a bike that’s too big for your child so they can grow into it but there’s two real reasons to try and avoid that. The first one is that having a bike that’s too big is going to be harder to handle, it will also mean getting on and off the bike will be more difficult.

The second reason is that many bike manufacturers, Commencal included, have designed the range with different sized wheels making it possible to leapfrog one if needed.

Commencal have got the Ramones 14, 16 and 20 inch models. You can go straight for the 14, miss out the middle one and go to the 20 next if desired. Some bike brands even design bikes that grow with the child.

Armed with this info, you can get on to the manufacturer’s websites and look for the bike that fits. We’ve created a list of manufacturers we’d recommend below;

  • Commencal
  • Frog
  • Pinnacle
  • Black Mountain
  • Ridgeback
  • Specialized Riprock
  • Saracen 
  • Cube

See our article where we pick our best bikes available from these manufacturers here

Bike Types

This brings us on to different types of bikes. You’ve got balance bikes, starter bikes, kids’ mountain bikes, and junior mountain bikes.

Commencal’s range is fully-focused on the off-road, 100% mountain bikes from the 12 inch balance bikes, up to 14 inch.

Then you’ve got 14, 16, 20 and 24 inch starter mountain bikes and then on to the junior mountain bikes, these are proper hard tails and they come in 20, 24 and 27.5 inch wheel options.

Then to finish off the range they offer some real bangers, proper full suspension trail bikes. They come in 20, 24 and 27.5 inch wheel options.

Commencal use pro racers like Amaury Pierron and Myriam Nicole to develop their adult bikes and just like that, within the walls of the Commencal offices, there are plenty of parents.

They use their kids to help develop these bikes and they say that they concentrate a lot on the ergonomics and geometry of the bikes to make sure they’re great for off-road riding.

Other kids’ bikes are available, things like E-bikes, road bikes, BMX and all-purpose bikes and you can read on which is best suited for your kids here in a previous article we wrote.

Things To Look For

Whichever type of bike you go for, there are some key hallmarks that mark out a real bike as appose to a bicycle-shaped object. The first one is lightweight frames and components.

Lighter means an easy and more effortless and fun ride. Aluminium is king for kids’ bikes.

Ergonomics for kids

There are plenty of components that are really designed around kids, things like the smaller diameter handlebars, shorter reach brake levers so little hands can reach them.

Shorter cranks and a narrow Q factor so the pedals are closer together. All make up a bike that is designed for kids to ride.

Comfortable and confident geometry

Kids’ bikes are designed to be more upright just so they’re not stretched out as much. this makes it more comfortable for them and they also have low-bottom brackets which have a centre of gravity making the bike super stable.

Kids Components

If you go to your local hardware superstore or even supermarket, you’ll probably see some very bright, stick-it-up cartoon themed bikes, or at least they look like bikes, but they’re actually bike-shaped objects.

When you see a proper kids’ bike from a repeatable bike manufacturer, you’ll see a massive difference. You’ve got aluminium frames and components which will make the bike much more capable.

The use of proper kids components that are designed specifically to suit the ergonomics are the real hallmark of a proper kid’s mountain bike.

Commencal say that the cockpit is really important to suit smaller hands, things like the size of the bars, the levers, the grips and the shifts, it’s all designed to make it really usable by kids.

Contact points, the saddle, handlebars and grips should be the right size for little bodies. In the case of bars and grips that means having a smaller diameter so that little hands can get grip easier.

Brakes should be designed specifically to be closer to the bars for a shorter reach. Some will have a noticeably lighter action too, making braking almost effortless for little hands.

Crank length is also in proportion for correct saddle height and to get a low bike with plenty of crank clearance from the trail. The same for it’s paddle height, the lower the better.

The narrower the Q factor, the horizontal distance between cranks, the better. This means that smaller rider’s legs will go up and down efficiently as they pedal, rather than being bowed outwards.

Balance Bikes

90-110 cm height, 2-3 years approximately, with 12-14″ wheels

No need for pedals when you’re this young, kids on balance bikes can just use their feet, scoot along and really get used to riding a bike and getting their balance.

Also, when they get a bit better, they can start putting their feet up on that little platform. They’re designed for two to three year olds. When my kids were this age they absolutely loved their balance bikes.

There are also different wheel-size options if you require. You can get these in 12 or 14 inches.

Balance bikes actually take away the need for a kids’ bike with stabilizers because kids will learn how to ride on the balance bike. They’ll learn how to lean in to corners and things like that. Then hopefully when they go to pedals it should be a bit easier.

Narrow bars, upright position and the commencal range in particular even comes with knobbly tires. If you really fancy doing it, you can even stick a disc brake on the back. You should set the saddle height so that the kid’s feet are flat on the floor, still with a bit of bend in the knee.

There’s even a balance bike world championships out there you need to check out.

You should expect to pay somewhere between the range of 80 to 200 bucks for a brand new balance bike and you can view the range I’ve discussed in this article here.

Balance Bike Vs. Training Wheels

Balance bikes versus bikes with stabilizers or training wheels. Many people now go straight to balance bikes, they are great for getting kids to learn how to make speed with their feet and balance on a bike.

Whereas stabilizers do help kids get up to speed quicker and get them used to pedalling faster, you’ve got that massive leap of faith when you take your stabilizers off and the kid has to do it all for themselves.

So, nowadays you’ll probably find that most people tend to go towards balance bikes. I think they’re a great way of kids learning how to fall off at a slow speed.

Although I have heard from some parents that their kids love their balance bike so much they’re reluctant to start pedalling, but every kid’s different.

You can still use the training wheels to help develop when teaching to pedal and we’ve written a very helpful article on how to teach your kids to pedal, following the steps I took with my kids and you can view this here.

Starter Bikes

95-120 cm height, 3-5 years approximately, with 14-16″ wheels

These are the first bikes you’ll find with pedals on them. They’ll be single speed for simplicity so kids don’t have to learn about gears at the same time.

They will also have an upright position so kids aren’t scrunched up and they can see where they’re going.

With saddle height you need to get the kid sat on the saddle with one foot on the floor and with the pedal on the other side at the bottom, make sure the knee is slightly bent, but make sure they can really touch the floor confidently.

Most of these bikes will have a chain guard to make sure that the chains are all hidden away. Away from interested fingers where kids might start putting them.

Also, many brands will have larger versions available. The Ramones Commencal range, comes in 14 and 16 inch wheel sizes. So a bigger frame, bigger wheels, same simplicity.

Kids’ Mountain Bikes

115-150 cm height, 5-10 years approximately, with 20-24″ wheels

Onto Kids mountain bikes, now they’ve jumped up a bit in size but they’re more recognizably a mountain bike shape.

Most of these bikes are probably going to be rigid, although you can get options with suspension forks, it will probably be an air suspension fork, so they’re lighter and they’re easily adjustable with changing riding weight.

We’ve also now gone from one gear to many which will open up the terrain you can ride these on.

Commencal have the Ramones 20 and 24 inch wheel frames, both are seven speed bikes. These kids’ mountain bikes start at about 350 bucks up to about a thousand.

Junior Mountain Bikes

145+ cm height, 10 years plus approximately, with 26-27.5″ wheels

These are proper mountain bikes designed for proper riding. Also, a couple of these might be a good option for smaller adults that can’t fit an adult bike.

The Meta Junior range are really good quality bikes with parts from brands you’ll recognize. On the smaller wheeled bikes you’ve got manitou junior suspension forks, going up in travel to the Junior bike, a 27.5 inch wheel bike with rock shocks recon forks on them.

You also get Sram gears on all these bikes.

The Meta Hardtails are available in 20, 24 and 27.5 inch wheel size, so a big range of height difference in riders.

Full Suspension

Commencal have also created probably the coolest bikes I’ve ever seen and that’s the Clash range. There 20 inch Clash especially, it’s a very small big-hitting bike.

Up to the Junior bike, absolutely no compromise made here either. A 27.5 inch wheeled bike, 160 mil travel front and rear, you get big brakes, Sram guards, the 200 mil front router and 180 rear.

This bike could do some pretty big, pretty impressive riding.

Even the suspension internals have been designed to give kids the best stuff, scaled down to suit them.

As Commencal explain themselves, the Kinematic is designed to fit very low-weight riders, by using a very high ratio they can have decent air pressure in the shock and standard hydraulics. Without this, it would be impossible to have a bike made for kids.

Expect prices to range from about 600 bucks up to 2500 bucks. Yes, that’s a lot of cash but you won’t find many bikes in your life that keep their value as well as a good kids’ bike.

As soon as yours grows out of it, someone else’s will probably grow into it.

Hopefully you’ll find this information useful if you’re going to buy a proper kids’ bike. If you want to see any of the bikes mentioned in this article please click on the links above.

The Warburton Family

Everything we write is tried and tested. We research everything before putting it out to the world. Thanks for reading :-)

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