[This article was last updated on March 15, 2018]
There's probably never been more choice and quality in kids' bikes, from balance bikes for toddlers to scaled-down mountain bikes, BMXs and racing bikes for the budding Victoria Pendleton and Bradley Wiggins.
Children love to ride and a bike is one of those presents they will remember forever. It's an opportunity to get off the sofa and get outside having some fun; if you give them the right bike it can be the gateway to a lifetime of healthy exercise, exercise and adventure. Youngsters can start riding at any age from about three upwards, and can start on balance bikes even earlier.
So what do you need to know before you buy a bike for your child?
Kids' bikes are sized by wheel size rather than frame size, because the size of the wheels determines the proportions of the rest of the bike. The smallest kids' bikes have 12-inch wheels and are usually suitable for kids between three and five years old.
As with any bike, it's important it fits comfortably so that junior can easily stand across the frame, reach the pedals from the saddle and grab the handlebar without too much of a stretch.
In my far-off bike shop days I often encountered parents who wanted a bike for their child that was too big, so they could grow into it. If the rider to be was a boy I'd gently lift the front wheel to simulate a dismount on a slope and ask if they ever wanted to be grandparents.
Sloping frames and high resale values for good kids' bikes make this less of an issue than it was, but it's worth bearing in mind that a child's bike still needs to fit like an adult's, with an inch or two of top tube clearance, and more for mountain bikes.
It's even more important that kids' bikes aren't too heavy than it is for adults. A heavy kids' bike is relatively even more work for the rider than a heavy adult bike.
Kids' bikes used to be universally boat anchors, and very cheap ones still are. But there's been another revolution in the last few years, led by companies like Islabikes that have taken advantage of inexpensive manufacturing to produce bikes that were every bit as light as their grown-up equivalents.
Islabikes has been followed into the market by other kids' bike specialists and mass-manufacturers like Trek and Specialized have also raised their game with sensibly priced, light machines for young riders.
In the last decade or so, balance bikes - steerable toy bikes with no pedals - have revolutionised the way kids learn to ride. By allowing a child to learn to balance and steer a bike without the complication of pedalling, balance bikes make a child's first experiences with bikes simple and fun.
Balance bikes are available at a wide range of prices, from about £50 to £130. The most basic models don't have brakes but these days most have a rear wheel brake so junior's trainers don't get worn out stopping.
Bikes with 12, 14 and 16-inch wheels keep things simple with single gears and no complications. The big thing is to get a bike that fits, so your child can easily reach the ground, the handlebar's and the brakes. They are just starting out on their cycling experience and while they won't mind the odd fall when they are having fun, they will start to mind if it's more than the odd fall because they are too small to properly control the bike you've bought them. While it's quite hard to put children off cycling it's not impossible.
20-inch wheeled bikes
This is where you get into gears and sometimes suspension. Bikes for seven to nine year olds will take kids further afield, away from the garden and into parks and perhaps even to school.
You'll usually find six or seven gears to make climbing hills easier, with a twist-grip shifter for simplicity.
We're not convinced that a suspension fork is worth having at the typical £200-300 you'll pay for a good 20-inch kids' bike. Cheap suspension forks don't work very well, add extra weight and soak up budget the manufacturer could better spend on higher-quality parts to lighten the rest of the bike. Ironically the rigid version of some kids' mountain bikes will be lighter, nicer to ride and cheaper than the one with a suspension fork.
But kids, especially boys, seem to love those bouncy forks. If junior absolutely must have a suspension fork on his bike it's probably worth trying to make sure that the rest of the bike is as light as your budget will allow. Ideally you want to find one with a fork that can be locked out so they don't feel seasick when riding on pavements or tarmac.
The same comments apply to 24-inch and even 26-inch wheeled mountain bikes for kids as for 20-inch bikes.
You also find double and even triple chainsets on these bikes, but there's a school of thought that this is extra weight, complication and cost that the child can live without for another year or two. They may have other ideas, but if you need to argue your corner you can point to all those 1x9, 10, and 11 set-ups currently flavour of the month in mountain biking circles.
Road or mountain?
Small-wheel kids' bikes have flat bars and mountain bike styling, but once you get into 24-inch wheeled bikes you have the option of drop bars.
At this point you're definitely into try-before-you-buy territory. Some kids simply don't get on with drop bars, and more importantly with their brake/gear levers, so don't try and surprise your youngster with a road bike if you're not certain they'll cope.
Cyclo-cross style extra brake levers are a definite bonus on any drop-bar bike for a kid and in our experience children will thank you for them. One other note on brakes for all kids' bikes: always check that the brake levers are proportionate to the size of the child's hand that's going to be using them, and ideally that they are reach-adjustable too.
And don’t forget BMX
There’s a good shout for saying that the BMX is the ideal kids’ bike, it’s relatively light, simple and robust. That robustness means BMXs have great hand me down and/or re-sale value. More importantly from a kid’s point of view they’re fun to ride and are pretty much go-anywhere machines.
Add in the fact that there are all sorts of types of BMX riding you can do and that many towns and cities have a BMX track or some ramps for learning tricks and stunts on, or simply just ragging around with your mates and what’s not to like. As a sport BMX has been something of a breeding ground for champions both on the road and track in recent years, and of course in BMX too.
One of the other great things about BMX bikes for kids is that they’re a small wheeled bike anyway and the original BMXers were kids, so kids' BMXs really are proper scaled down versions of the adult ones. ‘Proper’ BMX bikes come with wheels as small as 12in, small enough for many four year olds. As with any other bike for a child it’s really important that you buy one that fits the child you’re buying it for. A full size BMX may have a 20in wheel, as do many children’s bikes, but that doesn’t make it a child’s bike.
Again, like other bikes with a BMX you get what you pay for. Because of its simplicity a cheaper BMX probably offers better value than a cheap mountain bike in terms of the quality of the frame and components.
As with mountain bikes it pays to keep it simple when buying a BMX for a child. Stunt pegs and the like may look cool/rad/sick but like cheap suspension forks on kids mountain bikes they just add weight and cost at the expense of performance.
…or BMX-style bikes
Some of the best kids bikes borrow a lot from BMX bikes and single speed dirt jump mountain bikes without quite being either. The Islabike Cnoc and Beinn models are good examples, so is the Raleigh Performance 16 (pictured). Simple, tough, one-geared bikes for children from five to nine years old that are generally even more versatile than a BMX often lighter too and which kids really seem to enjoy riding.
16 great kids' bikes
German outfit Puky's range of balance bikes starts from as little as £53 with their LRM balance bike and they offer a whole range including models with pneumatic tyres, kickstands and brakes. All of them are light and extremely durable - they really are built to last with a tough powder coat finish, but that functionality isn't at the expense of fun. The kids we know who've had them have really enjoyed using them and we'd go so far as to say they're a bit of a classic. Certainly if you want to give your child a fun start to a life of cycling £60 spent on the LRM is likely to be prove a very sound investment. Puky's website has a very useful guide to help you choose the right balance bike for your sprog. Like most other kids' bikes it really comes down to size.
Another great little balance bike. We love the simple lines of this balance bike from the Ridgeback range. The frame is 6061 aluminium which keeps the weight down and there's a proper sealed-bearing headset, unlike the bushings you find in very cheap balance bikes.
There's a V-brake at the back to slow things down and the cable is even routed internally. Who doesn't appreciate clean lines on their bike?
With this 5.79kg aluminium-framed first bike, Islabikes throws out the wheel sizing rules we were talking about above and offers a bike with 14-inch wheels for the youngest riders.
Islabikes' attention to detail is legendary and it's on show here with short-reach brake levers, small-diameter handlebars, and lightweight wheels. It all adds up to a luxury package for youngsters and if your sprog's not yet ready to fly solo it'll take stabilisers.
This Giant mini-mountain bike is a typical kids' 20-incher. Part of Giant's Liv women's range, it has an aluminium frame in Giant's own ALUXX alloy, wide-range seven-speed gears and V-brakes.
There is also a boys' version, the Giant XtC Jr. 20.
British brand Charge makes very well-regarded mountain bikes, town bikes and road bikes with a distinctly UK slant. Its recently added some very tasty looking junior mountain bikes. The Cooker 24 has 24-inch wheels, as the name suggests, on an aluminium frame to keep the weight down. There's a single chainring and seven-speed sprockets for uncomplicated shifting, and disc brakes for speed control.
We make no apologies for including another Islabike; Isla Rowntree really did rewrite the book on kid's bikes, and the Beinn 24 is a terrific flat-bar kids' bike.
It's surprisingly light and well-proportioned, well-made, well-designed and perfect for kids from seven to nine years old.
Perhaps the best thing about Islabikes is their almost cult-like following means they hod their value incredibly well. It's not unusual to see secondhand Islabikes for sale at only 10% less than new price.
Its sheer versatility makes the Worx JA24 one of the best kids' bikes we've ever tested. Not only does it look great, but you can choose road or knobbly tyres depending in whether your young 'un wants to ride tarmac or dirt.
Weight's kept down with an aluminium fork, and there are plenty of carefully-chosen details to fit young riders, including a particularly well-shaped handlebar.
The larger-wheeled Worx is also a blinder, with all the properties and features that make the 24-inch bike so good. Kids grow quickly, but moving up from the 24-inch to 26-inch Worx will be a seamless transition, and there's a 700C bike too for the next step up.
If your aspiring Wiggo or Vos just wants to go fast on the road, Scott's Speedster JR is perfect for your junior, er, speedster.
The Speedster JR 24 is as serious about the business of going fast as Scott's top end carbon fibre Foil models, and Scott's designers have obsessed over the details.
Proportional frame tube sizes ensure the bike looks like a scaled adult race machine, not a puppy with dog's paws. It also goes a long way to helping keep weight low. They've even removed the chainstay bridge.
The price is a lot of money for a kids' bike, but it the spec measures up with highlights like very light wheels, Shimano Sora gears and sidepull brakes and if you shop around you can get it for less than the list price.
What we were saying above about not needing suspension on a kids' bike? Here's the exception. The Hot Rock 24 is a proper hardtail mountain bike, scaled down. It has a coil-sprung SR fork and the aluminium frame keeps everything light. Specialized says it's as tough as an adult cross-country bike's frame.
Canyon has a range of three MTB-styled kid's bikes, of which this is the top model. With a good quality suspension fork, lightweight frame, wide-range gearing and hydraulic dis brakes, it's a proper modern hardtail mountain bike, scaled down for kids between 120cm and 153cm tall.
A drop-bar bike with 26in wheels, but unlike the Raleigh, Frog goes with chunkier tyres out of the box so that the Road 70 can handle trails and dirt roads as well as tarmac.
If it were an adult bike we'd be using lots of current hot cycling buzz words 'cross', 'adventure' or 'gravel'. In fact, it's some and none of those. It's just a kids' bike, built for kids to take on the sort of freewheeling, where-the-wind-blows sorts of rides they like to do.
Trek knows that adventurous kids will ride everywhere no matter what a bike's supposed to be for — remember dirt tracking on racers when you were a kid? The Kids' Dual Sport is a go-anywhere rigid 26-incher for roads and trails, though the dread word 'hybrid' is carefully avoided.
You get an aluminium frame and fork, triple chainset and disc brakes - the latter still a rarity on kids' bikes but a welcome confidence-booster for weaker junior digits.
The Islabikes Luath 700 Small is among the smallest and therefore easiest to access full-sized 700C-wheel road bikes.
Testers felt the ride was sporty and responsive: "not like I expect a cross bike to feel like" as one put it. The Luath changes direction easily, responding to a light touch, without feeling fly-away or skittish – just what young riders need in a fast road bike.
Descending seems to be a particular penchant of the Luath, gobbling up sweeping turns with an appetite only beaten by that of the growing rider. We put this down to good geometry, a relatively compact cockpit, a fork that gives the front end a planted feel, and grippy Kenda tyres.
And then there's the Islabikes Pro Series, almost certainly the highest-spec production kids' bikes ever made. Every detail has been minutely examined and when Islabikes hasn't been able to find off-the-peg parts for the job, they've designed their own. Weight has been kept to a minimum, with components like a titanium bottom bracket axle and an all-carbon fibre fork.
The range starts with the Cnoc 16 Pro Series for £799.99 and goes up to the Luath Pro Series with 24-inch, 26-inch or 700C wheels. They're not cheap, but the only other way to get a kid's bike anywhere near this good would be to have it custom built.
Our official grumpy Northerner, John has been riding bikes for over 30 years since discovering as an uncoordinated teen that a sport could be fun if it didn't require you to catch a ball or get in the way of a hulking prop forward.
Road touring was followed by mountain biking and a career racing in the mud that was as brief as it was unsuccessful.
Somewhere along the line came the discovery that he could string a few words together, followed by the even more remarkable discovery that people were mug enough to pay for this rather than expecting him to do an honest day's work. He's pretty certain he's worked for even more bike publications than Mat Brett.
The inevitable 30-something MAMIL transition saw him shift to skinny tyres and these days he lives in Cambridge where the lack of hills is more than made up for by the headwinds.