Ideal for a young rider around primary-school age who wants an easy, low-maintenance geared bike for neighbourhood rides, school runs and shared paths.
If you’re looking for a kids’ bike that keeps things simple without feeling basic, the Radius Trailraiser 3 hits a really practical sweet spot. You get a 20-inch alloy frame, low stand over height and junior-specific geometry that help young riders get on and off easily, feel balanced at low speed and build confidence as they start riding further from home.
What really sets this bike apart is the Shimano Nexus 3-speed internal hub. For many families, that means less fuss than an exposed derailleur setup and an easier way for kids to learn when to change gear on bike paths, around the neighbourhood or on smooth gravel. Paired with the coaster rear brake and short-reach front brake lever, braking stays intuitive for riders who are still developing hand strength and coordination.
This is the sort of bike we’d recommend for everyday Australian riding where the goal is reliability, easy ownership and a comfortable fit rather than trail-bike aggression. The 560mm riser bar, adjustable quill stem, slick 20 x 1.75 tyres and centre kickstand all add up to a bike that’s straightforward, tidy and well suited to regular family use.
Shimano Nexus 3-speed hub
Internal gearing keeps shifting simple and tidy, with fewer exposed parts to knock out of adjustment.
Low stand over 6061 alloy frame
Makes it easier for kids to hop on, stop safely and feel more confident as they learn.
Junior-specific geometry
Balanced handling helps younger riders steer predictably and stay comfortable on everyday rides.
Front hand brake plus coaster rear brake
A familiar, confidence-building setup that lets kids use both foot and hand braking as their skills grow.
Short-reach brake lever
Better suited to smaller hands, so front braking feels easier to control.
560mm riser bar and adjustable quill stem
Gives an upright riding position and useful fit adjustment as your child grows.
20 x 1.75 slick tyres
Roll smoothly on pavement and hard-packed paths, making the bike feel easier to pedal.
Kickstand and double chainguard
Practical everyday extras that help with parking and keep clothing away from the chain area.
Frame & Fork
Drivetrain
Brakes
Wheels & Tyres
Cockpit
General
Radius Junior geometry
We set this bike up with junior-specific geometry to give young riders balanced handling and a confident fit as they build skills.
Low stand over height
The low stand over makes it easier to hop on and off, helping kids feel secure when starting, stopping and manoeuvring.
Shimano Nexus inner 3 speed shifting
The internal 3-speed hub keeps shifting simple and tidy, with low-maintenance gearing that suits everyday rides on paved and gravel paths.
Steel straight blade fork
The straight blade fork gives the bike a sporty look and responsive steering for fun, easy handling.
Youth specific short reach brake lever
The short reach lever is easier for smaller hands to use, so braking feels more controlled and comfortable.
Junior specific saddle and grips
The junior saddle and grips help keep rides more comfortable, whether it's the school run, family cruising or local path adventures.
Great for
Maybe not for
Radius places its 20-inch geared bikes in the 7–10 years range. As always with kids’ bikes, overall height, confidence and inside-leg clearance matter more than age alone, and the low stand over plus adjustable quill stem give a bit more room to grow.
vs Giant ARX 20
The ARX 20 is a lighter, more performance-oriented 20-inch kids’ bike with an aluminium fork, youth-specific fit details and a stronger focus on efficient pedalling and wider-range gearing.
vs Specialized Riprock 20
The Riprock 20 is a much more trail-ready kids’ bike with hydraulic disc brakes, 8-speed gearing and mountain-bike geometry aimed at real off-road riding.
vs Liv Adore 20
The Adore 20 is an easy-riding 20-inch kids’ bike with a low standover frame and coaster brake, but it stays single-speed and is aimed more at first pedal-bike confidence than progression into geared riding.
A sensible first geared bike
For plenty of kids, 3 internal gears is the sweet spot. It gives enough range for gentle rises and longer rides without the complication of a derailleur, trigger shifter and multiple sprockets hanging off the back.
Best on paved and smooth surfaces
The slick 20 x 1.75 tyres and rigid fork make this bike feel easier to pedal on bike paths and around the neighbourhood, but they also tell you what the bike is for: everyday riding rather than rough trail use.
Good fit adjustability matters at this age
The quill stem gives more adjustment than many kids’ bikes, which is handy when a rider is in between sizes or having a growth spurt. That can help you get longer use before the jump to 24 inches.
Braking setup suits developing skills
A coaster rear brake keeps stopping intuitive, while the short-reach front lever helps kids start learning proper hand braking with better control.
Radius is an Australian-designed bicycle brand within the Apollo Bicycles stable, focused on accessible bikes for kids, families and recreational riders. The range centres on practical designs, approachable fit and everyday value rather than specialist racing or high-performance categories.
The brand is known for building entry-level and family-friendly bikes with comfort-focused layouts, easy handling and a broad spread of wheel sizes. Radius also highlights Australian design, value for money and a limited lifetime warranty as core parts of the brand offering.
