Before we get started, a quick hello from me. If you’ve been around the blog for a while, you’ll know me as Miss Frugal. I’m helping out a bit more while Mum takes some time to rest, and I’m learning the ropes of blogging as I go. This post came about after a chat at work with someone who’s trying to buy a bike for their daughter for Christmas and feeling completely stuck between sizes. It’s one of those purchases that sounds simple but turns out to be anything but. We spent ages on Google and CHat GPT learning everything we needed to know and I now feel like the World’s biggest expert.
If you’ve got a bike-mad child, you’ll know how awkward the timing of growth spurts can be. One minute the current bike still fits “well enough”, and the next you’re wondering whether to stretch to an adult bike or find something that sits in between. That’s exactly what we were talking about at work — the worry of buying something too small that won’t last, or something too big that feels unsafe.
That “in-between” option is often a 24-inch bike, and it’s a size that quietly solves a lot of practical and financial headaches. Brands like Bobbin Bikes design 24-inch bikes to give children a real step up in independence and performance, without the cost or complexity of jumping straight to an adult model.
When you get the size right, a 24-inch bike can last for several years, which often works out cheaper than rushing through two badly sized bikes that never quite feel comfortable. It’s best thought of as the final children’s bike before adulthood — big enough for riding to school, clubs and friends’ houses, but still built around a child’s body rather than a scaled-down adult frame.
Why the 24-Inch Size Matters
When we talk about a 24-inch bike, we’re referring to the wheel size, not the frame. Most sizing guides suggest this size suits children with an inside leg of around 20 to 25 inches, which usually covers the later years of primary school.
Age charts often say something like “8 to 12 years”, but anyone who’s stood at the school gates knows how unreliable age is when it comes to sizing. Inside leg measurement is far more honest because it tells you whether your child can actually straddle the bike, pedal comfortably and still get a foot down quickly if they need to stop.
This is where the 24-inch category really comes into its own. It bridges the gap between smaller kids’ bikes and compact adult frames. You start to see features like multiple gears and stronger wheels, but the reach, standover height and controls are still designed for shorter riders.
For a lot of families, this means buying one bike that genuinely lasts rather than constantly upgrading. A child can go from riding around the street to tackling longer routes on the same bike, instead of being pushed onto a heavy adult bike they struggle to control.
Getting the Fit Right (and Keeping It Safe)
The best place to start is with a tape measure, not a price tag. Measure your child’s inside leg from the floor to the crotch, without shoes, and compare it to the bike’s recommended range. If they’re roughly in that 20 to 25 inch band, you’re looking at the right size.
Then comes the real-world test. With the saddle set at a sensible height, your child should be able to sit with a slight bend in the knee at the bottom of the pedal stroke and still get the balls of both feet on the ground when they stop.
Handlebar height and reach matter just as much. If their elbows are slightly bent and they’re not stretching forward or hunching over, the bike will feel far more comfortable and controllable, especially on longer rides.
One thing that really helps from a budget point of view is adjustability. A decent range of saddle height and adjustable handlebars can easily add an extra year or two of use. As your child grows, raising the saddle gradually allows the bike to grow with them instead of forcing an upgrade just because they’ve had a sudden summer growth spurt.
Safety-wise, look for brakes that are strong but easy for small hands to use. Well-set-up V-brakes or disc brakes with child-sized levers make a big difference. Tyres with decent tread help on wet school runs or muddy paths, and a sturdy but not overly heavy frame makes everyday use much easier.
Some 24-inch ranges, like Bobbin’s kids’ bikes, strike a really nice balance between child-friendly fit and grown-up styling. That feeling of riding a “proper” bike can be a big confidence boost and often encourages kids to ride more regularly.
Knowing When It’s Time to Move Up
At some point, even the best 24-inch bike will start to feel small. The signs aren’t always obvious at first. You might hear complaints about knees hitting the handlebars, notice the saddle can’t be raised any higher, or realise they look cramped in photos.
Technically, it’s time to think about an adult bike when the seat post is close to its maximum height and your child still can’t get that slight bend in the knee at full extension. If they’re hunched over the bars or brushing their knees on tight turns, they’ve probably outgrown the frame.
Moving to an adult bike isn’t just about wheel size. Small adult bikes often have longer frames, different gearing and components designed for heavier riders, so it’s worth trying a few options in person if you can.
A good tip is to let your child test ride both their current 24-inch bike and a small adult bike on the same route. Ask which one feels easier to start, stop and look around on. Comfort and control matter far more than moving up a size just because friends have bigger bikes.
If the adult bike still feels like a stretch, there’s no harm in sticking with the 24-inch bike for another season. A confident rider on a slightly smaller bike is far safer than a nervous rider on one that doesn’t quite fit yet.
Final thoughts
From a frugal point of view, a well-chosen 24-inch bike can be one of the best-value purchases in a child’s cycling journey. It covers the years when they ride the most and, when sized by inside leg rather than age, can see them through several growth spurts.
By focusing on fit, adjustability and safety, it’s possible to buy once and get years of use out of a bike. And when the time eventually comes to move up to an adult model, your child will already have the confidence and skills that come from riding something that truly fits.
Another post done with no emojis. Don’t tell Mam!
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