24- or 26-inch mountain bike for a child? Choosing an MTB for forest tracks and trails
Your child is ready to leave the tarmac and try gravel paths or forest tracks. Should you look at a 24-inch mountain bike or move up to 26-inch wheels? Start with how the whole bike fits. Don’t choose by age alone. Your child’s height, inside leg length, riding confidence and the bike’s geometry all matter.
MTB stands for mountain bike, but the name covers different uses. A bike for family rides on forest roads is not automatically suitable for jumps or demanding trails. Check the intended use of the exact model in our mountain bike range.
24 or 26 inches: where should you start?
The number refers to the wheels, not the length or height of the frame. Two bikes with 26-inch wheels can fit very differently. Use age as a rough starting point, then compare the manufacturer’s sizing guidance and the bike itself.
| What to compare | 24-inch MTB | 26-inch MTB |
|---|---|---|
| Fit | Compare the rider’s height and inside leg length with the maker’s guidance. | Check frame height and reach as well as the maker’s height range. |
| Handling | Smaller wheels can be easier to manoeuvre when the whole bike fits. | On otherwise similar bikes, larger wheels roll over obstacles more easily. |
| When to consider it | The rider can reach the controls and start, turn and stop comfortably. | The frame and controls allow the rider to start, turn and stop confidently. |
Avoid buying a bike that is too big in the hope that your child will grow into it. They need a bike they can control now.
Five checks to help you get the fit right
- Measure height and inside leg length. Measure barefoot from the floor to the crotch, then compare both measurements with the manufacturer’s guidance.
- Check standover clearance. Your child should be able to stand over the frame with both feet on the ground and suitable clearance above the top tube.
- Check the reach. They should hold the bars without overstretching and turn them freely.
- Try the brake levers. Small hands need to reach the levers and apply the brakes effectively. Have the controls adjusted for the rider.
- Take a short test ride. Practise starting, stopping and turning somewhere suitable. Lowering the saddle will not fix a frame that is too long.
Between sizes? Compare the exact models rather than choosing by wheel size alone. There is no height range that works for every 24- or 26-inch bike.
Does a child’s mountain bike need suspension?
Not every forest ride needs a suspension fork. For smoother gravel and forest roads, a rigid fork can keep weight and maintenance down. On rooty or more uneven routes, a suitable suspension fork can help with comfort and control.
The suspension needs to respond properly to your child’s weight. An air fork must be set up according to its instructions; other types of fork also need to suit the rider. Do not choose by appearance or travel alone. A suspension fork is of little use if it barely moves under your child’s weight.
What else should you check?
- Weight: can your child handle the bike, lift it over a small obstacle and pick it up after a stop?
- Gears: useful low gears and a shifter they can operate matter more than the number of gears.
- Tyres: choose tread for the routes you ride. Set pressure within the tyre and rim limits, taking rider load and conditions into account.
- Intended use: check what the model is designed for. A recreational MTB is not automatically a jump or bike park bike.
The same checks apply when choosing a bike for a boy or a girl. Fit, control and the intended riding come first.
MTB or BMX for your child?
For longer forest rides, climbs and varied surfaces, the gears and riding position of a suitable MTB can be useful. If the main aim is skatepark riding, street tricks or learning BMX skills, compare our BMX bikes instead. In either case, match the exact model to the riding your child wants to do.
Assembly and checks before the first ride
A bike ordered online may need the pedals, handlebars or front wheel fitted. Follow the instructions supplied with the exact bike rather than assuming every model arrives in the same state.
RMDBike requires an initial service by a professional bicycle workshop before the first ride. Have the workshop complete or check the assembly, brakes, gears and settings. The workshop sets the price; keep confirmation of the work and follow the supplied instructions and warranty documents. This requirement does not limit your statutory consumer rights.
Read our important information before buying and using a bike before ordering and riding.
Keep the first forest rides manageable
Start with a short, easy route. Practise braking, turning and coming to a controlled stop before trying more technical terrain. Use a properly fitted helmet; choose gloves and protective pads to suit the riding.
After a muddy ride, clean the bike and check the drivetrain. Before the next ride, check tyre pressures, brakes and wheel fixings. Follow the bike’s inspection and maintenance instructions.
Two junior mountain bikes to compare
Here are two models from our range to help you compare. Their suggested height ranges are a starting point — check how the bike fits your child before buying.
- Dartmoor Hornet Junior 24-inch — a 24-inch option with an XS size listed for approximately 130–150 cm. £594.24.
- CTM Rocky Jump 26-inch — a 26-inch junior MTB with a 14-inch frame and an XS size listed for approximately 135–155 cm. £442.17.
The overlapping height ranges show why wheel size is only one part of the decision. Prices and stock can change; check the selected size on the product page. You can also browse junior mountain bikes. If you are unsure, tell us your child’s height, inside leg length, riding experience and usual routes so we can help compare the options.
Questions about 24- and 26-inch mountain bikes
24 or 26 inches for a child who is 140 cm tall?
Both may be worth comparing, depending on the model. Check the manufacturer’s sizing, standover clearance and riding position. A low, short junior frame with 26-inch wheels can fit differently from an adult 26-inch bike.
Can a child ride a 26-inch mountain bike?
Yes, if the frame and controls fit them. Compare junior geometry and equipment rather than assuming that any bike with 26-inch wheels will work.
Should I buy a bigger bike for my child to grow into?
Choose a bike they can control now. If they cannot reach the brakes, steer freely or stop confidently, extra room to grow is not a good trade-off.
Is suspension essential for forest rides?
No. A rigid fork can suit smoother tracks. For rougher routes, a fork that works properly under the child’s weight can be useful. Match the bike to the terrain and the rider.
