The single biggest mistake with kids' bikes is buying by age instead of by size. Here's how to pick the right wheel size for your child, what actually matters on a children's bike, and what good ones cost.
Kids' bikes by the numbers
Walk into any shop and the bikes are labelled 'ages 5–8' — but kids the same age can differ by 20 cm in height, so those labels are close to useless. What matters is the wheel size, matched to your child's leg length, plus a bike light enough for them to actually handle. Get those two right and everything else follows.
“Buying a size up 'to grow into' is the most common — and most expensive — mistake parents make. An oversized bike is harder to control, so kids ride it less.”
Size by wheel, not by age
Kids' bike sizing
| 12" | 14–16" | 20" | 24" | 26" / S adult | |
|---|---|---|---|---|---|
| Child height | 85–100 cm | 100–120 cm | 115–135 cm | 130–145 cm | 145 cm+ |
| Rough age | 2–4 yrs | 4–6 yrs | 6–9 yrs | 8–11 yrs | 10+ yrs |
| Approx. inseam | 35–42 cm | 40–50 cm | 48–60 cm | 58–68 cm | 66 cm+ |
Specs: BikeBuy editorial · composite of major kids' bike charts
View data table
| Wheel size (inch) | |
|---|---|
| 2–4 | 12 inch wheel |
| 4–6 | 16 inch wheel |
| 6–9 | 20 inch wheel |
| 8–11 | 24 inch wheel |
| 10+ | 26 inch wheel |
What actually matters on a kids' bike
Weight is king. A bike that's a big fraction of your child's body weight is a handful to steer and pedal — lighter bikes genuinely get ridden more. After that: brakes they can reach and squeeze (short-reach levers matter for small hands), simple gearing (a single gear is fine until about 20″; too many gears just confuse), and a low, easy standover so they can stop and put both feet down with confidence. Skip the heavy 'suspension' forks on cheap bikes — they add weight and do nothing.
New vs used for a growing child
- Used saves a lot — kids outgrow bikes in 1–2 years, so second-hand makes sense
- A lightly-used quality bike beats a new heavy big-box bike at the same price
- Good kids' bikes hold value — you can resell when they grow
- Check used bikes for rust, seized brakes and worn tyres
- You may wait to find the right size second-hand
- New means a warranty and a shop to set it up safely
Balance bike or training wheels?
A balance bike — no pedals, feet on the ground — teaches the one thing that's actually hard about cycling: balancing. Kids who start on one from around age two typically skip training wheels entirely and pedal off first try. Training wheels, by contrast, teach kids to lean on the stabilisers and delay real balance. If you're starting from scratch, start with a balance bike.
What good kids' bikes cost
Popular kids' bikes, live from the tracker
Lowest current offers across SA retailers, by wheel size.
Kids' bikes: common questions
What size bike should I buy for my child's age? +
As a rough guide: 12″ for ages 2–4, 14–16″ for 4–6, 20″ for 6–9, 24″ for 8–11, and 26″ or a small adult bike from about 10. But fit to your child's height and inseam — they should be able to sit and put a foot flat on the ground.
Is a balance bike better than training wheels? +
Yes, for most kids. A balance bike teaches balancing directly, and children who use one from about age two usually skip training wheels and pedal away on their first proper bike. Training wheels tend to delay real balance.
How much should I spend on a kids' bike? +
Roughly R1 500–R2 500 for a first 12″ pedal bike, R3 000–R5 000 for a 20″, and R4 000–R6 500 for a geared 24″. Because kids outgrow bikes fast, a good used bike is often the smartest buy.
When should my child move up a bike size? +
When they've outgrown the current one — knees hitting the bars, saddle already at its highest, or they look cramped. Don't rush it: a bike that's too big is harder and scarier to ride, which slows their progress.
Are cheap supermarket kids' bikes okay? +
They'll work, but they're heavy, often poorly assembled, and quickly worn. A lighter bike from a proper bike shop — new or used — is easier for a child to ride and much safer, and it holds resale value.
Measure your child, match the wheel size to their height, and prioritise a light bike with brakes they can reach. Start beginners on a balance bike, and lean on the used market since kids grow so fast. Check the full sizing chart in our bike sizing guide, and browse kids' bikes in the marketplace.
