Best kids 20″ wheel mountain bikes for 5 and 6 year olds

If you're desperate to start mountain biking with your child, then the move up to a 20 inch wheel bike marks a turning point in your cycling life!

20 inch mountain bikes are thankfully becoming more popular all the time as manufacturers realise kids are wanting to get out on the trails from a really young age.

In this article, we take a look at some of the best kids 20" wheel mountain bikes that are currently on sale in the UK for kids from around 5 or 6 years of age.

If you're not sure if your child will need gears and/or suspension, read our article Buying a kids mountain bike – things you need to know.

If your child is going to be riding on all types of surfaces, such as grass, tarmac and road, then an MTB might not be suitable for them, so please take a look at our article on the best 20" wheel hybrid bikes for bikes that are more all round.

Cycle Sprog is a reader-supported website. When you buy through links on this page we may earn an affiliate commission.

How much does a 20" wheel 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" wheel 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" wheel 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.

The best 20 inch kids mountain bikes

Kids mountain bikes come in all price ranges, so we've tried to cover a wide variety in this article.

A word of warning - there are some very cheap, very heavy MTBs that claim to be full suspension but don't actually work out on the trails.

You're better off getting a bike with no or front suspension that is fun and safe to ride out on the trails.

BTwin Rockriders are the in-house brand of kids mountain bikes at Decathlon, and they come in a range of prices and specifications.

They're suitable for kids between 120 and 135 cm in height.

The BTwin Rockrider ST 100 is the most basic 20 inch kids mountain bike and is a single-speed steel framed mountain bike, suited for gentle riding on or off road.

The next level up is the Rockrider ST 120, which is similar to the ST 100 but comes with 6 gears so means hills become easier.

The Rockrider ST500 20 adds in front suspension to make the bumps on the trail smoother, but will add weight to the bike (this model weighs in at 12.4kg)

These BTwin Rockriders offer a really good value entry level mountain bike that should provide plenty of scope for fun during summer riding on green and blue grade MTB trails.

However if you're looking for something to handle more challenge rides the Rockrider ST 900 is the top specification mountain bike in BTwin’s 20″ wheel mountain bike range.

With a lightweight aluminium frame, front suspension, 6 speeds and grippy tyres and front disc brake this is a great value bike for introducing your child to the joys of mountain biking.

It weighs in at 10.5 kg which is a considerable weight saving over the ST500, making it easier for your child to ride and for you to carry /lift on to a bike rack.

Price range: £159.99 - £299.99

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Cube are a German bike brand, so you know you're getting precision engineering and an attention to detail with these bikes. Our own Cycle Sprogs have been lucky enough to ride some of their larger top of the range Cube MTB's so we're fans of their bikes!

Their 20 inch mountain bikes are sized for kids 111 - 124cm tall with an inseam of 49 - 57cm.

Cube realise that kids aren’t always the most careful or thoughtful so features of their bikes include a modulator on the front brake to stop them slamming on too quickly, plus an easily replaceable derailleur hanger – the bit that changes the gears that gets damaged when kids drop their bike on the floor gears side down (TOP TIP –  teach them to lay their bike down derailleur side upwards!).

Their entry model 20" wheel kids MTB is the Cube Acid 200. This bike 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 £429

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Orbea are highly regarded bike builders from Basque Country. We like the fact that they take kids bikes seriously, and are creating some fine examples of 20" wheel mountain bikes that are scaled to suit young riders.

They have two 20 inch mountain bike models to fit kids 110-135cm tall. The Orbea MX is their regular range, and the Laufey their premium range.

Each bike has multiple specification variations in each (so it can get a bit confusing but we'll do our best to explain!)

The Orbea MX 20 Dirt is best described as the base model in the MX range. It has an aluminium frame with rigid steel fork, v-brakes, 7 speeds (14-34T / 36t) and 2.2" wide tyres.

If you want front suspension then you need the MX 20 XC which is specified with a coil sprung fork giving 40mm of travel.

For kids also riding to school the MX 20 Park is the Dirt fitted with lights, kickstand, mudguards and narrower (1.75") reflective tyres.

The Orbea MX Team is an upgraded version of the Dirt, with 8 speeds (11-34T / 32t) and a lighter weight aluminium rigid fork.

If you're looking for a top of the range 20" mountain bike, the entry level Orbea Laufey 20 is the H30. This kids MTB has a rigid aluminium fork, hydraulic disc brakes, 9 speeds (11-36T/32T) plus upgraded saddle, seatpost and drive train over the MX range.

The Orbrea Laufey H20 gives you an air fork with 80mm of travel, dropper seat post, upgraded stem, tubeless ready wheels and Schwalbe Rocket Ron foldable 2.25" wide tyres.

And top of their 20" wheel mountain bike range, with an air fork with 100mm of travel and upgraded headset, sits the Orbea Laufey H10.

Price range: £415 - £1,149

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

They've now introduced a couple of larger wheel sizes to the range, with the HÜTTO being the 20 inch model.

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.

Aimed at kids aged roughly between six and eight and a half, Black Mountain uses its EPOK growing frame design so it can start off in small pedal bike mode and be extended to large pedal bike mode as your children grows.

Price range: £499 - £699

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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.

Price range: £670 - £810

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The Trail 20 is Cannondale’s aluminium-framed mountain bike offering for children aged 5-8 years old.

The Trail 20 kids mountain bike features front suspension, courtesy of a SunTour XCT-JR 20, a 7-speed twist shifter and 1.95" multi-surface tyres.

The higher spec version of this bike is the Cannondale Trail Plus 20w featuring a rigid fork, mechanical disc brakes and grippy, oversized tyres to soak up bumps and grip the terrain.

Price range: £400 - £480

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Prevelo is a mountain bike brand which is highly regarded in the US and these bikes are now available in the UK.

The Prevelo kids mountain bike Alpha Three offers 9-speeds which is the most out of any 20 inch MTBs we've listed here. The geometry keeps the rider low, which will help your child keep their balance and be in control on the trails.

This kids MTB comes with a lightweight aluminium frame, v-brakes and a rigid fork.

The other 20 inch mountain bike in Prevelo's range is the high performance Prevelo Zulu Three, which includes front suspension, hydraulic disc brakes and 10-speed drivetrain.

Price range: £549.95 - £1099.96

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The best kids 20" 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.


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 🙁


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


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…


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

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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