Stay smaller if…
- They're a first-time rider — smaller is more confidence-building
- They're a cautious kid by nature
- Their inseam is at the bottom of the next size's range
- You want a bike they'll master fast, not grow into
Sizing Guide
Pick the right size. Once.
Three minutes, one tape measure, no guessing. Here's how we match an Aussie kid to an Aussie bike — and what to do when they're between sizes.
01How to measure
Three numbers. That's it.
We size by inseam first because it's what matters most when feet need to touch the ground. Height tells us how the bike will feel as they grow into it. Skill level tells us how much bike to actually give them.
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01
Inseam
Stand them barefoot, against a wall. Measure from the floor up to the top of the inner thigh — not the waist. A book between the legs (spine up to the crotch) gives you the number with no fuss.
Most important for the Ride 10" and Rippa 12". -
02
Standing height
Total height, head to floor. We use this as a sanity check against inseam — long-legged kids might fit a bigger size comfortably even when inseam says otherwise.
Useful for spotting between-size kids. -
03
Skill level
Have they ridden before? If yes, what kind? A confident pump-track five-year-old needs a different bike to a five-year-old just learning to balance. Be honest with us — we'd rather get this right.
Tilts the recommendation up or down a size.
02Find their bike
Tell us their numbers.
Height, inseam, skill level. Three numbers, one bike. Skip ahead to the matrix below if you'd rather see the full size chart.
Enter the numbers. We'll match the bike.
Recommendations are guides, not gospel. Between-sizes guidance and the full size matrix sit just below if your kid's on the edge.
03The size matrix
Find your size.
Numbers below are riding-fit guides — the inseam where most kids ride confidently, not the absolute minimum or maximum.
| Bike | Age | Inseam | Height | Best for | Shop |
|---|---|---|---|---|---|
| Zippi Ride 10"The original | 2–8 | 34–50 cm | 85–128 cm | First-timers, training wheels included | Shop |
| Rippa 12"First Rippa | 2–6 | 38–52 cm | 90–120 cm | Confident toddlers, balance-bike grads | Shop |
| Rippa 16"Pump-track ready | 5–10 | 50–65 cm | 110–140 cm | Skate parks, bush trails, growing kids | Shop |
| Rippa 20"Big kid energy | 8–12 | 58–72 cm | 125–150 cm | Confident riders, longer rides, real speed | Shop |
| Rebel 20" ProThe step-up | 8–13 | 60–78 cm | 130–160 cm | Trail-ready kids stepping past pump tracks | Shop |
| Rebel 24" ProThe flagship | 12–15 | 75–90 cm | 150–178 cm | Teens stepping into proper e-bike territory | Shop |
Inseam ranges overlap on purpose — kids fall between sizes and that's fine. If your kid's number sits in the overlap, the next section helps you decide which way to go.
04Between sizes?
Stay or size up?
The most-asked question at Zippi HQ. Here's the call we'd make if it was our kid — because for two years it was.
Size up if…
- They've already got balance dialled on a smaller bike
- They're tall for their age with long legs
- They're going to outgrow the smaller size in 6 months
- You're happy to wait a few weeks for them to grow into it
Honest take: if your kid is genuinely between sizes and you're stuck, go smaller. A bike that fits today gets ridden today. A bike that's too big sits in the garage waiting for legs that haven't arrived yet.
05When they outgrow it
When do they need the next size?
Most kids get two to three years out of a Zippi. The bike doesn't wear out — the kid grows. Here's how to tell when it's time.
Signs they've outgrown it
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Feet flat on the ground when seated
If they can stand the bike up between their legs with feet planted flat, they've outgrown the inseam. They're not balancing — they're walking it.
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Knees hitting the handlebars
Their riding position is bent. Look at them from the side — if their knees are coming up toward the bars, the frame's too small.
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Asking for speed they can't get
They've maxed out mode 2 and want more. The current bike can't physically deliver — time to move up the range.
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Riding gets shorter, not longer
They used to do laps; now they do five minutes. Often a cramped fit problem, not a motivation problem.
Not the end of the bike
Built to be handed down.
When your kid outgrows their Zippi, the bike isn't finished. We hear from families on their second or third rider on the same frame — big brother to little sister, cousin to cousin, neighbour to neighbour. Our frames are built durable enough to outlast the kid riding them. Spare parts ship from Tasmania when something eventually wears out.
06Sizing FAQ
Stuff parents actually ask.
How long will my kid get out of one size?
Two to three years for most kids. Adjustable seat posts give you a decent runway, and our frames are built durable enough to outlast the kid riding them — ready for the next one in line.
What if my kid is between two sizes?
Read the section above — the short version: a bike that fits today gets ridden today. Sizing up only makes sense if they're already a confident rider or about to hit a growth spurt.
Can my kid ride a Zippi if they can't pedal yet?
Yes — all six Zippi bikes are throttle-only. No pedalling involved on any of them, including the Rebel Pros. The throttle limiter on every bike lets you cap the top speed while they learn.
Are the seats and handlebars adjustable?
Yes on every model. Both seat post height and handlebar height adjust with hand tools. We err on the side of generous adjustment range so the bike grows with the kid.
What if I get the size wrong?
Email us before it's ridden and we'll sort an exchange. Once it's been ridden it can't come back, but we'll do everything we can to help you find the right setup.
Do training wheels affect sizing?
Not really. Training wheels (included free with the Ride 10", available as an optional add-on for the Rippa 12") just give a smaller kid more confidence on day one. Sizing is still about feet-to-floor inseam reach.
07Still not sure?
Tell us your kid's numbers. We'll match the bike.
Real humans — on the other end of an email, in our Tasmanian warehouse. We've sized thousands of Aussie kids by now. Send us their age, inseam, height, and a sentence about their riding so far.
