Parents ask us this every day: "How old does my kid need to be?"
The honest answer is it depends on two things — age and confidence — and the right bike meets them where they are today, not where you hope they'll be in two years. Getting this right matters. Put a 5-year-old on a bike built for a 9-year-old and you'll spend six months watching them be terrified. Put a 9-year-old on a bike built for a 5-year-old and they'll outgrow it in one school term.
Here's how we think about age, size, and skill — matched to the actual bikes in our range so you can see where your rider fits.
The two questions that actually matter
Before you pick a bike, answer these two:
1. Can they already ride a balance bike or a pedal bike with training wheels off?
If yes, they're ready for a motor. Balance — the ability to stay upright while moving — is the one skill that can't be faked by a bike's features. Once they've got it, everything else (braking, steering, throttle control) can be taught.
If no, don't start with a powered bike. Buy them a $60 pushbike from Kmart, spend three weekends at the park, and come back when they've got balance sorted. We'd rather lose the sale than sell you a bike your kid can't actually ride yet.
2. How confident are they around speed and failure?
Some kids are wired for it. They'll fall, get back up, and ride harder. Others are cautious — they want to go slow, they hate surprises, they'll cry if they drop the bike. Both personalities can ride; they just need different bikes and different speed modes.
A bold kid can ride a bike that's a size up from their age bracket and be fine. A cautious kid needs a bike that's bang-on for their age, with the speed limiter dialled down until confidence builds.
With those two questions answered, here's the age-by-age breakdown.
Ages 2–6 — The balance bike years
Recommended bike: FXB03-12 Pro Cross Electric Balance Bike — $1,299
If your rider is aged 2-6 and already has balance, this is where they start. A 12-inch electric balance bike is the most fun a small kid can have on a motor.
The FXB03-12 has:
- Training mode at 10 km/h — the speed of a brisk walk. You can literally keep up with them on foot. Parents love this mode because you can let a 3-year-old rip and not panic.
- Mode 2 at 15 km/h — once they've got the hang of it, flip them up a mode. This is backyard track speed.
- Mode 3 at 20 km/h — top mode for when they're 5 or 6 and asking for more.
- No pedals, no chain — balance bike design. They steer with the bars, thumb the throttle, and the bike does the rest.
- Removable battery — charge it inside, ride outside.
What the FXB03-12 isn't: it's not a jumping bike, not a trail bike, not something a 7-year-old will still fit on. Outgrown in 2-3 years, which is normal for kids' bikes at this age.
Height guide: fits riders roughly 85-115cm tall. If your kid is on the tall side of 5, they might already be better suited to the 16-inch below.
Ages 3–8 — First "real" dirt bike
Recommended bike: FXB SX-E2 Pro Cross Electric Dirt Bike — $1,899 (currently $1,799 on sale)
This is the bike for kids who've outgrown a balance bike and want something that looks and rides like a real motocross machine. 14-inch wheels, proper dirt bike styling, three speed modes up to 40 km/h.
The SX-E2 is where a lot of kids fall in love with riding. It's the first bike where they're going faster than they can run. The styling matters — it looks like a grown-up bike, and at this age, that's half the magic.
What we'd flag: 40 km/h in Mode 3 is genuine speed. For a 4-year-old we'd leave it in Mode 1 (15 km/h) for the first three months. For an 8-year-old with confidence, Mode 2 (25 km/h) is the natural starting point.
Height guide: 105-135cm.
Ages 5–9 — The graduation bike
Recommended bike: FXB03-16 Pro Cross Electric Balance Bike — $1,799 (currently $1,299 on sale)
If your 5-9 year old has balance-bike skills and wants to step up, the FXB03-16 is where most parents land. 16-inch wheels, hydraulic disc brakes (not cable), three speed modes, proper suspension.
Why this bike specifically:
- Hydraulic brakes are a genuine safety upgrade over cable-pull brakes. Shorter stopping distance, less hand strength required, more predictable bite.
- 16-inch wheels roll over bumps that would stop a 12-inch wheel. Kids at this age ride rougher terrain.
- Three progression modes mean the bike grows with skill. Start slow, unlock speed as they earn it.
Height guide: 115-135cm.
Ages 7–12 — The serious moto bike
Recommended bike: FXB04-16 Pro Cross Electric Dirt Bike — $2,199 (currently $1,299 on sale)
This is where kids transition from "riding around" to "riding MX style." The FXB04-16 has the geometry and componentry of a full-size dirt bike, scaled down. Proper motocross stance, chunky tyres, genuine dirt-bike styling.
Kids at this age want to jump, ride berms, hit whoops. The FXB04-16's suspension and geometry can handle that in a way the smaller balance bikes can't.
What we'd flag: at this size, the rider's weight and skill start to matter more. A 7-year-old who's cautious might be better on the FXB03-16 above. A 7-year-old who's been riding since they were 3 will be ready for the FXB04-16.
Height guide: 120-150cm.
Ages 9–13 — Racing-style
Recommended bike: FXB06-20 Pro Electric Racing Bike — $1,899 (currently $2,099)
The FXB06-20 is our racing-style bike. Single-swingarm styling, 20-inch wheels, longer reach for riders who've stretched out a bit. This is the bike for kids who are riding seriously — 3 sessions a week or more — and want a bike that handles like a real machine.
Height guide: 130-170cm.
Ages 9–14 — Full-suspension dirt
Recommended bike: FXB01-20 Pro Cross Electric Dirt Bike — $2,499 (currently $1,799 on sale)
If the FXB06-20 is our racing bike, the FXB01-20 is our full-on dirt bike. Full suspension front and rear, proper motocross geometry, 20-inch wheels, the componentry to handle real trails and MX tracks.
This is the bike for kids who are doing technical riding — trails, MX tracks, jumps, rough terrain. If you're regularly taking them to a proper track or riding area, this is the one.
Height guide: 130-170cm.
Ages 12+ — The flagship
Recommended bike: FXB06-24 Pro Electric Racing Bike — $3,499 (currently $2,399 on sale)
The top of the range. 24-inch wheels, 55 km/h top speed, 36V 1500W motor, TIM hydraulic double-shoulder fork, FASTACE 190mm air shock — the componentry list reads like a real motorbike because it basically is one.
This is a teenager's bike. Tall teens, confident riders, kids who've already spent 2-3 years on smaller electric or petrol bikes and want something with serious pace.
Don't buy this as a first bike. It's too much bike for a kid who's still learning. Great second or third bike for a serious rider.
Height guide: 160cm+.
Signs they're ready (and signs they're not)
They're ready when:
- They can ride a non-powered bike confidently without training wheels
- They understand left hand = rear brake, right hand = front brake (or they can learn)
- They respect "stop when I say stop"
- They can physically reach the handlebars with a slight bend in the arms when seated
- They can flat-foot the ground or nearly so when seated (important for confidence)
They're not ready when:
- They can't balance on a non-powered bike yet
- They don't respond reliably to "stop" or "slow down"
- They're too short — feet don't reach the ground when seated, legs are straight reaching the bars
- They're only excited because their older sibling has one, not because they want to ride
"They'll grow into it" is the single most common mistake parents make. A too-big bike isn't just hard to ride — it's dangerous. Kids can't catch a falling bike they can't flat-foot, and every fall at this age knocks confidence.
Better to buy slightly small and upgrade in 2 years than to buy slightly big and watch them not ride it for 6 months.
The FXB range at a glance
| Bike | Age | Height | Price |
|---|---|---|---|
| FXB03-12 Pro Cross | 2–6 | 85-115cm | $1,299 |
| FXB SX-E2 Pro Cross | 3–8 | 105-135cm | $1,899 |
| FXB03-16 Pro Cross | 5–9 | 115-135cm | $1,799 |
| FXB04-16 Pro Cross | 7–12 | 120-150cm | $2,199 |
| FXB06-20 Pro | 9–13 | 130-170cm | $1,899 |
| FXB01-20 Pro Cross | 9–14 | 130-170cm | $2,499 |
| FXB06-24 Pro | 12+ | 160cm+ | $3,499 |
Currently a bunch of these are on sale — check individual product pages for live pricing.
Still not sure?
Honestly, the quickest way to get this right is to tell us your rider's age, height, and how much riding they've done, and we'll point you at the right bike. Email hello@ridefxb.au or call 0400 986 352. We'd rather spend 5 minutes on the phone with you than watch you buy the wrong bike online.
Factory direct means we're the people who built these bikes, not a middleman with a spreadsheet. Ask us anything.
