Buying a kids mountain bike - things you need to know

So your daughter or son has taken a liking to off-road riding and wants to get their hands on something larger and a bit tastier than their current bike. If you're considering buying a kids mountain bike (or even a small adult size if they're at that stage) take a moment to look through this post to make sure you're getting the best bike for your money.  In this article I'm going to be looking at 7 key areas you need to think about before parting with your hard earned money:

  1. Sizing of the bike
  2. Weight of the bike
  3. Budget
  4. Suspension vs rigid forks on a kids mountain bike
  5. Gearing - triple vs single
  6. Disc brakes vs v-brakes on a kids mtb
  7. Components (including tyres)

What age and height is the bike you're looking at suited for?

Remember that bike manufacturers size their products differently to one another, plus each child is an individual package too. Always check out the manufacturers size guidelines and carefully measure your child's inside leg, especially if you're buying over the internet.

Buying a kids 24 wheel mountain bike - Cube Kids Mountain Bike - 2017 range

It's always best to check the fit carefully before you buy and not rely on the age guides. For example, my eldest (a very tall young thing) had moved onto a child's 26" wheeled mountain bike aged 9, whereas my youngest will certainly be getting much more use out of the 24" wheel mountain bike.

Thankfully most brands provide some overlap between sizes, so the transition from 20 inch to 24 inch and 24" to 26" is easier to manage when it occurs.

Type of kids mountain bikes

It's very interesting to see how manufacturers view this sector of the market. Some invest heavily, with current trends in product design from the adult world spilling over and being utilised on the kids bike range. Others stick with the tried and tested triple chainset and v-brakes - a specification that happily does the job and tends to come at a cheaper price. It's when you start to look at disc brakes, a 1x10 narrow/wide chainset mounted onto a lightweight frameset and forks that the costs start to rise significantly.

How much should a kids mountain bike cost?

You can pick up a kids mountain bike from your local supermarket and pay less than £100. When I say pick up I don't mean that in the truest sense, as the reality is you'd probably give yourself a hernia. Sadly, kids bikes at this price are heavy and not built to withstand the rigours of mountain biking. They may look the part with 'suspension' front and rear, but that's where the resemblance to a mountain bike stops. A builder may have a use for the tubing though!

If your child is serious about going mountain biking then it makes sense to have the correct tool for the job. After all, you don't hammer nails in with a toffee hammer. It may look the same, but........ You get my drift.

A kids mountain bike doesn't have to cost a fortune

Yes, it is possible to break the bank and spend thousands of pounds on a kids mtb, but really these are tools suitable for a select few, already immersed in the sport and one day hopefully standing with a beaming smile on top of a podium. For the rest of us, decent kids mountain bikes exist for budgets that can't/won't/don't need to stretch that far. Take a look at our article of reasonably priced kids 26" and 27.5" mountain bikes to see the spectrum of what's available.

Gearing on a kids mtb

In junior sizes, mountain bikes will either come with a triple chainset or a single at the front, with a wide ranging cassette at the back.

Buying a kids 24" wheel mountain bike - rear cassette in monochrome

There is consensus that the single up front with wide-range cassette at the rear provides all the gears that you could need for the majority of situations and this is the way the majority of manufacturers seem to be moving. It's simpler, lighter, less cables, less thumb thingies to twiddle. It's also less confusing for younger riders, who only have to contend with one set of gears.   Note that most cheaper bikes will probably still sport a triple, with gear shifters for both hands.

Does a kids mountain bike need suspension?

This is an interesting question without an absolute answer as it will depend on several different factors. For example, where do you live and ride most of the time? What is your budget?

Guide to buying a kids mtb - Hoy Bonaly 24 in blue

The type of riding and terrain you encounter will have a bearing on what may suit best. If your child is doing mainly cross-country riding then rigid forks should suffice, whereas a technical downhill trail rider will probably be looking for a decent suspension fork.

Here's a few reasons you may want to go for rigid forks when looking at kids mountain bikes:

  • Riding with a rigid fork means that your child will have to learn to look for the most appropriate line on the trail rather than just riding over everything in their path. This can improve their bike handling skills at this young age - something that will be with them for ever;
  • Suspension forks add weight. Yep, even top end ones will usually weigh more than a rigid fork, something worth considering next time your child is plodding uphill;
  • Do they need suspension? If they're using their mountain bike to ride to school by road every day and then doing reasonably gentle cross country or forest park rides at weekends, then is really there a need to splash out on suspension?
  • Rigid forks don't really need any servicing - factor in time and costs for maintenance if you're going for suspension; and
  • Cost - a decent rigid fork will cost significantly less than an equivalent suspension fork. As with everything in life, you get what you pay for. Cheap suspension forks just don't work, fact. They add weight, height to the front end and not much 'goodness' at all.

So why go for suspension forks on a kids mountain bike at all?

Buying a kids mountain bike - suspension forks in monochrome

If you're child is regularly hurtling over rough boulder strewn landscapes, or frequently tackling red routes at trail centres then it may be worth considering some front end travel to improve the comfort of their ride. And lets face it, they're probably going to be moving onto more technical riding over the lifespan of the bike.

With a suspension fork they'll find it easier to keep up with you during this type of ride, as they can tackle harder features on the trail successfully.

Disc brakes vs v-brakes on a kids mountain bike

When you start to look at higher end kids mtb's then disc brakes start to make an appearance. Designed to make sure the bike stops very quickly, in all weather conditions and on all terrains, disc brakes will add cost and weight to the bike. They are worth considering if you child is:

a) doing technical or very fast downhill and

b) is a very competent rider, so knows how to use the disc brakes safely.

Remember that kids have cycled safely and happy with v-brakes for over a very long time, and it takes skill and experience to use disc brakes - if your child is a novice rider they may find the power of the brakes overpowering.


Manufacturers build a range of bikes that are then sent out to retail at chosen price points. To help achieve this (and be competitive with offerings from other brands) savings have to be made somewhere along the line. Often, a 'range' will have the same frame at its heart, but the quality of the groupset, wheels and other components will improve as the price heads north. Items such as the saddle, handlebar  grips and tyres can often be own brand or cheaper alternatives as the helps keep the overall price down.


One item that can make a real difference to the quality and comfort of a ride (apart from a comfy saddle!) is where the bike comes into contact with the ground - the tyres. A decent set of tyres, suitable for the type of riding your child does, will pay dividends.

Having tried climbing wet, muddy passes with tyres designed for gravel had my wheels spinning and me pushing in parts. Same location, same conditions but with appropriate tyres and not only did I have traction, but also a greater level of confidence in the bike and a bigger grin on my face.  If necessary, you can always upgrade a decent frame with better quality tyres.

What to look for when buying a kids mountain bike

So, to summarise, before you buy your kid their next mountain bike remember:

  1. Check the sizing is correct for them
  2. Check the weight - if it is too heavy it's not going to be any fun to ride
  3. Set your budget, remembering you get what you pay for at the very cheap end of the scale
  4. Decide whether they need suspension for the type of riding they'll be doing
  5. Look at the gearing and make sure it's not over complicated, but has a wide enough range of gears to get up hills
  6. Decide whether they have the skills to handle disc brakes
  7. Check the components such as tyres and saddles - but remember you can always upgrade these bits later

I hope you've found this article useful. I'd love to see what bike you end up buying - share your photos using #cyclesprog on Instagram or pop over to the Cycle Sprog Facebook page.

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Affiliate disclosure:  This post contains affiliate links - which means we get a small commission from anything purchased. This helps us to keep running the website, so thanks for your support!

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