Best 20 inch kids mountain bikes for 5-6 year olds

Scouring the best 20 inch kids mountain bikes for your young shredder?

This is the ultimate guide to finding the perfect mountain bike for children aged 5 to 8 years, helping them build confidence on the trails and enjoy the thrill of off-road cycling.

As kids grow more capable, a quality 20-inch MTB opens up a world of adventure, from local greenways to more challenging blue and red-grade singletrack.

We've reviewed and compared the top bikes on the market, from lightweight premium models with air forks to affordable options with reliable components.

Whether you're looking for a 20 inch wheel mountain bike with front suspension, disc brakes, or a lightweight frame, our in-depth analysis will help you make an informed decision and get your child on a bike that's safe, fun, and built to last.

Finding the best kids 20 inch mountain bike using this guide

At the start of this guide we list our quick picks - the best 20 inch kids mountain bikes available right now in the UK. These are our top three brands, perfect if you're after a fast recommendation.

We then move straight into our full list of the best 20 inch kids mountain bikes currently available, with insights into which riders each model will suit best.

Next, we share our top tips for buying a 20 inch kids mountain bike, covering everything from frame size and geometry to weight and intended use, so you know exactly what to look for.

And finally, if you’d like an in-depth look before making your decision, our complete buying advice section gives you all the detail you need to choose with confidence.

best 20 inch kids mountain bikes: a photo of a little girl riding the blue bike on a lake district hill on a sunny day

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Quick picks: best 20 inch kids mountain bikes for parents in a hurry

If you haven’t got time to scroll through this whole list, then here are our top three recommendations for 20 inch kids mountain bikes, covering a range of budgets.

Decathlon's Rockrider line is a great starting point if your child is keen to head off-road. With a choice of wheel sizes and models to suit different ages and riding ability, the range makes it easy to find a first mountain bike that fits both your budget and your child’s needs.

These bikes offer reliable performance on trails and tracks without being overwhelming or breaking the bank.

Plus with Decathlon’s “Second Life” buy-back scheme, you can trade in the bike when it’s outgrown, making this a practical and sustainable choice for family mountain biking.

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  • Best mid-level kids 20 inch mountain bike: - Cube Acid 200 - £399.00

The Cube Acid 200 brings the feel of a full-sized mountain bike into a kid-friendly package.

This is a brilliant choice if your child is ready to move beyond neighbourhood rides and start experiencing real off-road cycling.

It's a bike that’s tough, reliable, and confidence-inspiring from the very first ride.

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The Orbea Laufey 20 H30 takes everything to the next level: lightweight aluminium frame, 100mm suspension fork, simple 1x drivetrain, and powerful hydraulic disc brakes.

This bike is built for kids who want to tackle real mountain bike trails with confidence.

If your child is itching to go beyond family rides and really push their limits, the Laufey 20 H30 is a capable, confidence-boosting choice that’s as fun as it is tough.

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Best kids 20 inch mountain bikes

When it comes to 20 inch wheel mountain bikes, quality and price can vary significantly.

In this guide, we've selected a range of bikes to suit different budgets and abilities.

A word of advice: be cautious of very cheap, heavy kids mountain bikes with "full suspension." These often perform poorly on trails. For a safer and more enjoyable ride, we recommend choosing a bike with no suspension or a quality front suspension fork.

Btwin Rockrider 20 range

Best budget 20 inch kids mountain bike

best 20 inch kids mountain bikes: The Btwin Rockrider MTB 20 EXPL 900R on a blank background

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  • Price: £199.99

If your child is curious to try a bit of mountain biking but you don't want to fork out a lot of money, then Decathlon's Btwin Rockrider range is a great place to start.

They come in a choice of wheel sizes and model types (100, 500 and 900), so you can usually find something that suits your budget.

They're not the lightest bikes, but they're decent quality for this price point, and are designed with child-friendly components and geometry.

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Cube Acid bikes

Best mid-range 20 inch kids mountain bike

best 20 inch kids mountain bikes: Cube Acid 200

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  • Price: From £399

The Cube Acid 200 has an aluminium frame and steel fork, v brakes, 7 speeds (13-34T / 36t) and 2.1" tyres. It weighs in at 9.5kg.

For cycling to school, the Cube Acid 200 All Road gives you front and rear lights, a front hub dynamo to power them, kickstand and snap on mudguards. This adds 1.2kg.

An upgrade to the Cube Acid 200 Disc gives a lighter weight aluminium fork plus hydraulic disc brakes, which will give better stopping power in wet weather.

One cancels the other out weight wise, and this remains a 9.5kg bike. There's also a Cube Acid 200 Disc All Road version with the same accessories as before.

If you're looking for something a bit lighter/faster, then Cube Acid 200 SLX has v-brakes and an aluminium fork plus 9 speeds (11-42T / 32t). It weighs in at just 8.2kg.

Price: from £399

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Read more about the Cube Acid 200

Cannondale Trail 20

Best rigid 20 inch kids mountain bike

Best 20 inch kids mountain bikes: a Cannondale Trail in pink seen from the side

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  • Price: £420.00

The Cannondale Trail 20 is built with a lightweight and strong aluminium frame, making it easy for a child to control and manoeuvre.

The frame's design has a low top tube, which means it’s easy for kids to get on and off, boosting their confidence.

To handle bumpy trails and uneven paths, the bike features a Suntour front suspension fork.

The bike is equipped with a user-friendly 7-speed gear system that uses a twist-shifter, which is particularly easy for small hands to operate.

For reliable stopping power, the bike uses Promax V-brakes, which are simple and effective for children to use.

The Cannondale Trail 20 is a well-rounded and dependable bike, making it a good choice for parents who want to encourage their child's cycling adventures on a variety of surfaces.

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Read more about the Cannondale Trail 20

Orbea MX 20

Best 20 inch kids mountain bikes: Orbea MX 20 Dirt

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  • Price: from £479.00

Orbea, based in the Basque Country, have a strong reputation for building quality bikes, and their 20-inch mountain bike range reflects the same attention to detail as their adult models.

Orbea 20 inch mountain bikes come in two ranges: the MX and Laufey.

The MX line up includes the MX 20 Dirt is the entry-level option, with an aluminium frame, rigid steel fork, V-brakes, 7-speed gearing and wide 2.2" tyres.

The MX 20 XC adds a coil-sprung fork for 40mm of travel, while the MX 20 Park adapts the Dirt with lights, kickstand, mudguards and narrower reflective tyres for school and city use.

At the top of this range, the MX Team upgrades to an aluminium rigid fork and 8-speed gearing for a lighter, more versatile ride.

The Laufey range steps things up further. The entry-level Laufey H30 comes with a rigid aluminium fork, hydraulic disc brakes and 9-speed drivetrain.

The H20 introduces an air fork with 80mm of travel, dropper seatpost and tubeless-ready wheels, while the flagship H10 pushes this to 100mm of travel with additional high-end components.

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Read more about the Orbea MX 20 Dirt

Specialized Riprock 20

Best 20 inch kids mountain bikes: a blue specialized riprock 20

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  • Price: £500.00

You're likely to know about Specialized, they are one of the largest bike brands making adult bikes for most budgets- but we are really impressed with their kids range too.

The Specialized Riprock 20 is built with young riders in mind, combining high-quality materials and thoughtfully designed components to create a bike that’s both durable and capable.

The A1 Premium Butted Alloy frame is lightweight yet robust, featuring internal cable routing for a clean look and added protection and is compatible with a dropper post which offers a touch of future-proofing if you’d like to upgrade at a later date.

Equipped with C-STAR hydraulic disc brakes and 160mm rotors, the bike delivers impressive stopping power and brake leavers are adjustable for small hands. The microSHIFT 9-speed drivetrain makes cycling uphill easy and  trigger shifters makes changing gear easy for little hands.

Read the glowing Specialized Riprock 20 review here.

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Woom OFF 4

Best 20 inch kids mountain bikes: A black and silver woom OFF 4 leant against a stone wall

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  • Price: from £670.00

woom bikes is a range of premium quality Austrian kids bikes which includes hybrid bikes, a city bike, an e-bike and mountain bikes.

The woom OFF 4 is a 20″ wheeled lightweight kids MTB for children from 6 to 8 years (56 and 66cm inside leg).  It weighs in at just 7.8kg due to its lightweight aluminium frame and carbon fork.

The nine speed gearing is provided by SRAM X5 shifters and rear derailleur, with an 11-32T cassette matched to a 28t chainset.  woom have obsessed over things like crank arm length to ensure the optimum riding experience.

The woom OFF 4 is fitted with Promax hydraulic disc brakes and chunky 2.25″ Schwalbe Rocket Ron tyres.

Upgrade to the woom OFF AIR 4 and your kid gets to enjoy the benefit of an air suspension fork with 60mm of travel.

Read our glowing woom OFF 4 review here.

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Read more about the Orbea MX 20 Dirt

Carrera Blast

Best cheap 20 inch kids mountain bike

best 20 inch kids mountain bikes: A side view of the Carrera Blast mountain bike

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  • Price: Now £283 Was £315

The Carrera Blast is a good entry-level 20 inch wheel mountain bike from a convenient and accessible retailer.

While Halfords stock a number of cheaper models, these have ineffective suspension systems are very heavy and not ideal for genuine trail riding. The Carrera Blast, however, stands out as the best option in the Halfords range for a budding young mountain biker.

It features a front suspension fork to absorb bumps and a dependable 7-speed Shimano gear system with easy-to-use Revoshift shifters.

The V-brakes provide strong, reliable stopping power, and its off-road tyres are versatile enough for park paths and light trails.

In short, the Carrera Blast is a solid, reliable choice that offers a balance of quality and price for a child's first proper mountain bike.

If you have a daughter who would prefer something a little more feminine, then be sure to check out the Carrera Luna mountain bike as well.

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Read more about the Carrera Blast

Black Mountain HÜTTO

Best 20 inch kids mountain bikes: Black Mountain HÜTTO Trail 20 inch

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  • Price: from £599

Black Mountain is really taking the kids bike market by storm with their "growing bikes".

They have an innovative two-size frame, which does require you to be happy to tinker with a bike, and means if you get your child on this bike at the smallest available sizing you'll get loads of use out of it.

The 20 inch wheel HÜTTO is Black Mountain's largest bike, and come in different specifications depending on what type of riding your child is going to be doing.

The premium specification HÜTTO Trail (pictured) comes kitted out with disc brakes and front suspension, which is perfect if you're planning on tackling a lot of off-road riding.

All models come equipped with 7 speed SRAM Twist shift for hills.

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Top tips: choosing the best 20 inch mountain bike

  1. Size: 20" mountain bikes are typically designed for children aged 6 to 8 (around 115–135cm tall), but sizing can vary depending on the brand and the bike’s geometry. Always measure your child’s height and inseam before buying to make sure the bike will be a good fit.

  2. Price: While it might be tempting to pick the cheapest option, low-cost bikes are often heavy and poorly built. Spending a bit more usually means your child gets a bike that’s lighter, easier to ride, and far more durable.

  3. Weight: A lightweight frame makes a huge difference when kids are tackling off-road trails. Heavy bikes are harder to control uphill, over roots, or around corners—and you might end up carrying it at some point too! Look for aluminium frames rather than steel, and check the bike’s overall weight before buying.

  4. Get a bike, not a toy: Some bikes may look exciting with bold designs or gimmicky features, but if they’re poorly made, they’ll put your child off riding. A proper kids’ mountain bike should be designed with quality components and child-specific geometry to make riding safe, comfortable, and fun.

  5. Brakes and gears: Most 20" mountain bikes come with multiple gears to help kids handle different terrain. Look for simple shifting systems—such as 1x drivetrains with a single front chainring—so they can focus on riding rather than worrying about complicated gear changes. Strong, child-friendly brakes are also essential, especially for trail riding.

  6. Suspension or rigid: At this age, many bikes come with a front suspension fork, but not all of them are worth the extra weight. A good quality suspension fork can make riding rough trails more comfortable, but cheaper versions often add bulk without much benefit. For lighter riders or those sticking to smoother tracks, a rigid fork may actually be the better choice.

  7. Buy back schemes: Some retailers, like Decathlon, offer buy-back or trade-in schemes, so you can upgrade to the next size when your child outgrows their 20" bike. This can be a great way to keep costs down and ensure they always have a well-fitting ride.
best 20 inch kids mountain bikes: A boy seen from behind riding a 20 inch mountain bike along a gravelly path

How much does a kids 20 inch mountain bike cost?

Kids mountain bikes cost more than regular bikes, so be careful if you're buying a cheap mountain bike for less than £300.

For under £300 you can buy 20 inch mountain bikes which are suited to riding green and blue grade trails, and you can also find second hand bargains too.

However at this price point please be wary of badly made, heavy bikes. This is why we say a standard kids bike can often be much better value for money.

Once you spend £300 the quality of 20" mountain bikes starts to increase, and the bigger name brands often have entry level models in the £300 - £500 price range.

Between £500 and £800 the quality increases with bikes aimed a serious young mountain bikers. All these bikes should be capable of handling red grade trails.

If you have the cash you can keep spending to get the exact specification you want for your trail partner, with several MTB brands having 20" wheel offerings at more than £1,000.

Our 20 inch kids mountain bike reviews

At Cycle Sprog, we’re specialists in testing and reviewing kids’ mountain bikes, so our 20 inch kids MTB recommendations are based on hands-on experience and expert knowledge.

Below you'll find links to some of our reviews of the best 20-inch mountain bike for kids, focusing on quality, fit, and trail-ready performance.

If you’re unsure whether a 20-inch bike is the right choice, or you’d like to compare with other sizes, visit our Kids bike review page where you’ll find detailed reviews of the best bikes for every age and wheel size.

Best kids 20 inch wheel mountain bikes

So there you have it. A great selection of kids 20-inch wheel mountain bike brands that will have them tearing up the trails in no time.

This is just a  selection of what is currently available, so if you feel another bike or brand should be added to the list, please do drop a comment in the box below and share your thoughts.

Comments

David Marshall

I was very close to pulling the trigger on a Vitus 20plus but in the end have gone for a Bergamont Bergamonster Plus which is very similar in spec and with a 12% discount at Hargroves Cycles came in cheaper than the Vitus. I’ve immediately converted it to trigger shift with an £8.95 shifter from Amazon and it seems spot on.

Ruta Petrauska

Does somebody knows what the weight of Saracen Matnra 2.0 is? I have looked everywhere and can’t find anything 🙁

Karen

Hi Ruta – Saracen choose not to publish the weights of their bikes (they’re not alone in this, Giant are currently the same). If you contact them directly via their website they may choose to share this info with you. Karen

Ruta

Thanks! It’s just annoying that one can not find the weight of a bike, even when you search everywhere for a week. Some places says 7,1, some 8, some 8,2 or 8,5 kg – but these are all places you can’t really trust on. Maybe someone here has this bike at home and can weight it for the rest? I really would like to order it, but wat to know exact weight before it…

keith

I have had the same query.It is a critical piece of information in a chids bike.Why can Saracen not provide the information with the caveat “approximate” then I won’t be able to sue them form millions and millions of pounds(no, I wouldn’t)

Steve Burkett
Karen

Hi Steve, Thanks so much for taking the time to point that error out – I’ve updated it to reflect the forks are 40mm of travel. Glad you found the article helpful, Karen

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