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Best Kids Mountain Bikes

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Updated January 24, 2023

Whether you’re looking for the best mountain bike for a 12-year old boy or girl or a 5-6 year old just about ready to ride without training wheels, we’ve got you covered with our list of the best kids mountain bikes for sale today. We’ve researched, compiled reviews and compared key specs of the top youth mountain bikes, 24, 20, 16 and 26-inch sizes, focusing on safety features, ease of riding, and which bikes make the best learning platforms for bike treks across trails and mountain terrain. We looked at bikes for roughly 12-year old boys and girls, and at youth mountain bikes in general. Read on to find out some of the best bikes in the market too.

Our top pick, the Guardian Ethos, comes in 24” bike size, fits kids ages 10-12 and features “SureStop” dual circuit braking for safer stops. Read on for more of our top picks.

Top 5 Best Kids Mountain Bikes

 #1  Guardian Ethos Bike

Award: Top Pick

WHY WE LIKE IT: The Ethos kids 24 inch mountain bike has a lightweight steel frame making it easy to control, plus a patented single level brake system that’s great for beginners.

  • Safest
  • 7-speeds for easy hill climbing
  • Safe braking brake system for novices
  • More expensive than some
  • Lacks suspension travel

These Ethos kids mountain bikes are great for beginners and intermediate trail riders. Available as 20 inch or 24 inch mountain bikes, they are designed for girls and boys ages 8-12 and come with an included kick stand, adjustable seat height, 7-speed gears and a lightweight steel frame.

While they lack trail specific features of some kids mountain bikes like the Huffy (our #4 pick) the Guardian Ethos are all around great performing children’s bikes. They come with the patented “SureStop” feature which consists of a single brake level squeezing both front and rear brakes. An upgrade for the time when training wheels come off, these bikes are thoughtfully designed with kid-specific frame geometry allowing a lower center of gravity and lighter weight for better control. Speaking of control, check out the best electric bike for an easier ride.

 #2  Diamondback Cobra 20” Youth Mountain Bike

Award: Honorable Mention

WHY WE LIKE IT: This Diamondback hardtail is a great learning tool, with 40mm fork travel anda Shimano 6-speed gearing.

  • Also great intermediate riders
  • Steel frame with 40mm travel suspension fork
  • Powerful brakes
  • Too small for most 10-12 year olds
  • More complicated to operate than a single speed bike

A great thing about this Diamondback kids 20” mountain bike is that it’s generally beginner and intermediate friendly, with a low stepover height and wide tires, but it also makes a great learning tool for kids ages about 4-9. It has a Shimano 6-speed drivetrain with easy-to-learn trigger shifting, plus powerful brakes with both front and rear brake levers, so you can teach your kids good trail riding technique.

With a 20 inch fork, it fits kids ranging in height from about 44 to 54 inches. It weighs just under 29 pounds and is designed to be easy and forgiving to control. It also incorporates some durability focused features like a rear derailleur guard to help keep the chain properly connected. For adults who want a leisurely ride, we recommend the best adult tricycle. Another one of the best mountain bikes for kids is the Children’s Balance Bicycle Mountain Bike that’s made by Kids’ Road Bicycles. This balance bike comes in either 12 inch or 14 inch wheels. It also has multiple safety features like non-slip pedals, a fully-enclosed chain guard, and disc brake design that will give you a peace of mind when your child wants to go for a ride.

 #3  Guardian Original Kids Bikes

Award: Best lightweight

WHY WE LIKE IT: These aluminum frame kids mountain bikes are lightweight and come with Guardian’s SureStop braking feature, which prevents kids accidentally tripping just the front brake.

  • Best youth for safety
  • Aluminum frame weighs just 20 lbs
  • Versatile bikes for trail or road
  • More expensive than the Diamondback Cobra 20 inch
  • Lacks suspension

The Guardian Original children’s mountain bike line features a lightweight aluminum frame along with Guardian’s SureStop dual circuit braking system. This is designed mainly for beginners and helps prevent kids and those just learning to ride from accidentally squeezing just the front brakes. So while not ideal for aggressive riding where you might need independent front and rear braking, it’s a great safety feature for kids.

Available in 16, 20 and 24 inch kids mountain bike sizes, the Guardian Original is a versatile design that proves as capable on the road as it does on the trail. It’s not a full suspension mountain bike but the broad tires and aluminum frame do help it ride stably. This is great exercise for kids and if the older folks want some exercise they should read about the best recumbent bike for seniors.

 #4  Huffy Kids Dual Suspension Mountain Bike

Award: Best Budget

WHY WE LIKE IT: This inexpensive kids full suspension mountain bike is a great intro to trail riding for kids ages 5 to 9.

  • Also the best off-road
  • Shimano 6-speed
  • Fastest assembly of any 20 inch bike on our list
  • Bigger kids may outgrow it quickly
  • Heavier than the Guardian and not as easy for 5-7 year olds to ride

This Huffy kids mountain bike has a full suspension with front dual shocks and a rear spring so it soaks up bumps and dips in the trail. It has a 6-speed sprocket with indexed Shimano derailleur and twist grip shifting for easy gear changes, great for learning how to ride a multi-speed bike. It’s equipped with front and rear linear pull brakes for smooth stopping action.

A relative bargain among 20 inch kids mountain bikes, especially considering its sophisticated suspension, it has only a few drawbacks worth mentioning. It’s 5-10 lbs heavier than the 20 inch kids bike from Guardian, and lacks the Diamondback’s proven ruggedness and durability. To keep those tires inflated perfectly, you’ll also want the best portable air compressor.

 #5  Diamondback Tess 24 Inch Bike

Award: Best for 8-12 year olds

WHY WE LIKE IT: The Diamondback Tess is among the best 24 inch youth mountain bikes designed for 8-12 year old girls and boys with some bicycle riding experience.

  • Also the best off-road
  • Shimano 6-speed
  • Hi-Ten steel frame
  • Not as light or versatile as the Guardian series
  • More expensive than the similar Diamondback Cobra bicycles

This Diamondback youth mountain bike is primarily marketed for girls ages 8-12 and it has a number of features that make it an excellent learning bicycle for trails and advanced riding. It comes with a Shimano Tourney 21-speed drivetrain, giving it a very “big kids bike” number of gears. It also features sophisticated adjustable linear pull brakes and a durable, trail ready derailleur.

Thanks to a 40 mm-travel front fork it soaks up bumps well, even though it lacks the full suspension of mountain bikes like the Huffy Dual (our #4 pick.) A strong, yet light frame using Diamondback’s Hi-Ten steel helps maintain durability for longer trail rides or just reliable biking around the neighborhood. Also, check out the Pivot LES 27.5 Mountain Bike that has small and extra small frames to create a lower standover height, making this one of the best off-road bikes for young, little riders. It has a wheel size of 27.5 inches and is lightweight enough for young riders to lift and carry. With your kid ready to hit the road, make sure they bring along their best bike lock for safety.

How We Decided

In order to select the best kids mountain bikes on the market, we first looked at crucial safety features and we only included bikes that had front and rear brakes for balanced and quick stopping, a low step-over height and low center of gravity for safe, fun kids’ mountain biking. The easier to use dual-circuit single level brakes fitted to some children’s mountain bikes were a bonus.

We then included only models that were available in at least 20 or 24 inch sizes, since these allow kids ages 8-12 to progress comfortably and gain skill on a bike that feels appropriate in size. We wanted to include models appropriate for a first non-training wheels bike, as well as some mountain bikes that offered 12 year old kids some room to grow.

We only included youth mountain bikes with gears, using either trigger shift or grip twist shift. Kids’ bicycles with shock absorbing forks and full suspension were given extra credit. Though we’ve provided affiliate links to these products in our review, we still aspire to deliver honest, unbiased reviews of the best products on the market to our valued readers.

Best Kids Mountain Bikes Buyer’s Guide

Kids Mountain Bike Features to Consider

  1. Size
    You’ll want to make sure your kids’ mountain bike is the right size: comfortable enough to ride safely right away, but not so small that the kids will outgrow it in a month. The right size bike depends on the rider’s height and also on how comfortable and experienced they are. The typical size of the best mountain bike for a 12 year old boy or girl is generally considered to be around 24 inches, though some 11-12 year olds will prefer 26 inch bicycles.
  2. Frame
    Mountain bike frames are designed to be strong and lightweight, while giving plenty of room for wheel travel on bumpy trails. A kids mountain bike frame should have the same qualities, and in addition it should be well balanced and low enough that it provides ample safety and stability.
  3. Forks and Suspension
    If you’re looking for a youth mountain bike for serious trail riding, forks with suspension travel, ideally around 40 mm for a 20 to 24 inch bike, might be a good idea. A kids full suspension mountain bike is best for off road and rugged trail riding.
  4. Gears
    The best kids mountain bikes offer an opportunity to learn riding a bicycle with gears. Common drivetrain options include 6-speed, 7-speed and 21-speed. Finger trigger shifted gears are easier to use for beginners.
  5. Brakes
    Especially for mountain biking where you can run into steep hills and sudden obstacles, good strong brakes are a must for any bike for kids. Look for linear pull front and rear brakes with some adjustability and make sure the pads firmly grip the wheel or disc when the brake lever is pulled. There are different types of brakes on some bikes versus others, like v-brakes, hydraulic disc brakes, and mechanical disc brakes.

Kids Mountain Bikes FAQs

What is the best mountain bike for a 12 year old?

For a 12 year old between about 50 and 60 inches tall, the typically recommended mountain bike is a 24-26” “hardtail” such as the Diamondback bicycles on our list. For more dirt and downhill riding, consider a bike with full suspension like the Huffy Dual.

What is the best mountain bike for a 10 year old?

For a 10 year old with some bicycle riding experience, a 24 inch bike like the Diamondback Tess or the Guardian Ethos is usually a good fit.

What is a good inexpensive mountain bike for kids?

The Diamondback Cobra is a bargain among 20 to 24-inch kids mountain bikes. This hardtail has a quality fork with 40 mm of travel and a 6-speed Shimano drivetrain.

Should I get a hardtail or a full suspension mountain bike for kids?

Each has its pros and cons. A hardtail, meaning the front forks have suspension travel but there’s no rear shock or spring, is simpler, more durable and better for jumps. A full suspension mountain bike gives you the advantage of added control over bumps, especially when going downhill.
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