Best Bike For 4 Year Old: Sonic Nitro Junior BMX Review

Best Bike For 4 Year Old
best bike for 4 year old

Product Name: Sonic Nitro Junior BMX Bike

Product Description: Because of their compact size, lightweight design and rigid frame, BMX bikes are great for 4 year olds who are transitioning from smaller training and balance bikes. A BMX bike is easy to handle and introduces them to new riding skills. In a couple of years, they will be ready to get on a heavier mountain bike and hit the trails. The Sonic Nitro Junior Boys BMX is the best bike for 4 year olds. We love its bright yellow finish, the decals and the overall sporty styling that looks really cool. In terms of features, our favourites include the adjustable handlebars, child-friendly brake levers and the all-terrain tyres.

Availability: OnlineOnly

  • Design
  • Performance
  • Safety


4-year olds can be pretty choosy about what they want. Finding a good quality bike that meets their style requirements can be tricky. But I think the Sonic Nitro fits the bill.


  • Sturdy and durable construction
  • Cool BMX design with a bright yellow finish
  • Easy for kids to ride
  • Ideal for all kinds of terrain
  • Easy to assemble


  • No training wheels included
  • A bit heavy

What Are You Buying?

1. 16” BMX Bike with Adjustable Steering and Saddle

16” is just about right for 4 year olds. They are too tall for 12” and 14” bikes but are not yet ready for an 18” or 20” size.

But if you have a 4-year old who is tall for their age (check if their inseam is 22” or longer), you can go two sizes up to 18”.

But most kids will be good with this 16” size. For the perfect fit, you can adjust both the saddle and handlebar.

2. Cool Styling

Even without the bright yellow paint and the punchy graffiti, this bike would still look awesome thanks to its sporty BMX design.

The long slanted top tube combined with the BMX-style front fork gives the bike a unique cool style that your kid will love.

3. Calliper Brakes

Both wheels are fitted with calliper brakes linked to child-friendly levers on the handlebars.

I personally prefer simple calliper brakes on kids’ bikes.

They are reliable in all weather conditions, they are easy to maintain, they are easily adjustable and if they start to wear out you can replace the pads in a pinch.

4. Knobbly All-terrain Tyres

This bike is designed to be ridden in all kinds of terrains from gravel to grass and even mud. The knobbly 1.95” tires provide a strong grip especially on wet and slippery surfaces.

5. Good Quality Construction

The bike comes with a 10” steel frame. The steel does make it a bit heavy (12.5kg) but it also makes it more durable and hardier than lightweight aluminium frames.

As many parents have attested, this bike can take a beating without breaking or snapping. It works great whether they are riding on smooth pavement or rough and muddy trails.

How Easy Is It To Use?

You have to assemble the bike when it arrives. But it should take you no more than 15-30 minutes. Part of the bike is already assembled for you.

This is a single speed bike so kids should have no trouble getting used to it. There are no gear changes to make.

Something else I love is the use of calliper brakes on both wheels. Many kids’ bikes tend to have a calliper brake at the front and a coaster brake at the rear.

Coaster brakes are hard for younger kids to learn to use. With calliper brakes, they just need to press the lever.

What Accessories Are Included?

Other than the parts you need for the bike and the tools to assemble them, no other accessories are included.

There is no bell, training wheels or bonus water bottle. But these are things you can easily add yourself.


  • Sturdy and durable construction.
  • Cool BMX design with a bright yellow finish.
  • Easy for kids to ride.
  • Ideal for all kinds of terrain.
  • Easy to assemble.


  • No training wheels included.
  • A bit heavy.

Anything Else You Should Know?

This bike is meant for kids who have already learnt how to balance on a bike and control it.

If this is your child’s first ever bike, you may want to start with a cheap balance bike. Once they learn how to balance and steer, they can move on to this bike.

Alternatively, take off the pedals and ask them to scoot along with their feet until they develop balance.


4-year olds can be pretty choosy about what they want. They have reached an age where they demand cool stuff that they can show off to their friends.

Finding a good quality bike that meets their style requirements can be tricky. But I think the Sonic Nitro fits the bill.

Where to Buy

Leave a Reply