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12 inch bike tyres (most commonly with an ETRTO inner diameter of 203mm), are suitable for kids’ bikes, electric scooters, prams, pushers, buggies, and strollers. An affordable and practical option for replacing worn or damaged 12 inch bike tyres.
12 Inch Bike Tyres
Positz Essential Value Bundle of 2 Tyres 12 ½ x 2 1⁄4 (62-203) and 2 Thorn Resistant Tubes
(2)
$39.95
New
12 Inch Bike Tyres
Positz Essential Value Bundle of 2 Tyres 12 ½ x 2¼ (62-203) and 2 X-Tech Standard Tubes
$36.95
12 Inch Bike Tyres
12 Inch Bike Tyres are commonly used on young children’s bikes, balance bikes, prams, pushchairs, buggies, and some scooters. They're typically the first size of pneumatic (air-filled) tyres a child will encounter, offering a smoother ride and better traction compared to solid rubber alternatives. Whether you're replacing a worn-out tyre or upgrading for better quality, finding the correct size is essential.
Understanding 12 Inch Bike Tyre Sizing
12 Inch Bike Tyres in Australia are often labelled, and marketed, using inch-based measurements — for example, 12", 12½", or 12 x 1.75 — but these can be vague or inconsistent between brands. That’s because the "12 inch" figure refers to the approximate outer diameter of the tyre once it’s installed and inflated. It does not match the actual rim diameter.
To avoid confusion, manufacturers also use the ETRTO system, a system we at Mr Cycling World consider the gold standard (because it's accurate!) method of bike tyre sizing. For 12" bike tyres, the most common ETRTO number is 203, which refers to the inner diameter of the tyre in millimetres (ie. 203mm) - specifically where it fits onto the rim. The number that comes before it, for example 62, tells you the approximate tyre’s width once fitted and inflated in millimetres (62mm).
So while a 12" bike tyre might sound like it should fit a 305mm wheel, in reality, it sits on a 203mm rim. This misunderstanding is common — and it's why checking the ETRTO number on the sidewall of your existing tyre is the most reliable way to get the right fit.
Always check your existing tyre markings before buying, and match both the ETRTO diameter and width if possible.
If you're replacing tyres, there's a good chance you'll need a new inner tube as well. We stock a full range of 12 inch bike tubes to suit all common 12" bike tyre sizes — including straight and angled valve options.
All of our 12" tyres are stocked in our Adelaide warehouse and shipped fast, daily.