The Radio Cobalt Expert Bike is a black BMX race bike with a lightweight frame, durable tires, straight handlebars, and single-speed gearing—ideal for entry-level racers. Photographed on a white background.

The Radio Cobalt Expert Bike is a teal BMX race bike with black handlebars, seat, and tires. Perfect for entry-level riders, its design is inspired by Radio Raceline, combining style and performance against a crisp white background.

Radio Cobalt Expert Bike / Metallic Yellow / 19.5TT

Radio Cobalt Expert Bike / Black / 19.5TT

Radio Cobalt Expert Bike with a black seat, black handlebars, and black tires.

A light blue Radio Cobalt Expert Bike from Radio Raceline with black handlebars, black seat, and black tires is displayed on a white background.

Close-up of a teal-colored bicycle frame with the word "Radio Cobalt Expert Bike" on it, featuring black handlebars and brake cables, and a visible section of the front tire. This BMX race bike is perfect for those seeking an entry level ride to kickstart their racing journey.

Close-up of the front part of a teal BMX racing bike, showing the handlebars, brake cable, and the Radio Cobalt Expert Bike model name on the frame from Radio Raceline.

Close-up of a black bicycle seat mounted on a teal Radio Cobalt Expert Bike frame with tire partially visible.

Close-up of a teal bicycle's rear section, focusing on the brake system, wheel, and part of the saddle. This entry level Radio Cobalt Expert Bike offers excellent balance and durability for new riders.

Close-up image of the rear wheel and gear mechanism of a teal BMX race bike, showing the chain, spokes, tire, and frame from Radio Cobalt Expert Bike.

Description

Radio Raceline has continued its upwards trajectory in the "ready to race" category of complete off-the-shelf race bikes. Every one of their bikes in the Cobalt range can go from the shop to the podium with ease, and is the perfect entry level race bike for your young rider.

This beast is stacked full of loads of epic Radio parts to ensure a ride like no other! Radio Raceline Cobalt Grips provide loads of grip for your hands, The Radio Raceline Cobalt Hubs laced up to double walled Radio Raceline A-M5 Rims, which means they can take a beating you shredder starts to send the jumpks. After all, every BMX kids just wants to jump stuff, and this bike will take that punishment as they learn the ropes of BMX racing.

With incredible paint and graphics, you’ll be able to spot a Cobalt on the track very easily. All cobalt bikes now feature full sealed front hubs and integrated headsets, making them simply unbeatable when comparing price to spec. the cobalt is one seriously unstoppable machine.

We sell loads of these complete race bikes, and for good reason, awesome build quality at this price point makes them extremely great value and will last a season or two before your racer grows into the next size.

Features

Ready to race off the shelf. Radio Raceline build the Cobalt range to go from the shop to the podium, which makes this a sound first race bike.
Alloy frame, 19.5" top tube. 6061-T6 alloy with a 73° head angle, 13.6" chainstays and forged dropouts with an internal chain tensioner.
Fully sealed hubs, double wall rims. CNC alloy Cobalt hubs on 28H A-M5 double wall rims, so the wheels take a beating once your shredder starts jumping.
Chromoly fork and bars. A Cr-Mo fork with 23mm offset and seamless 4130 bars at 5.75" rise and 24.5" width, while they learn the ropes of racing.
8.95kg with 42 x 16 gearing. A light bike with a 54.08" gear ratio on 165mm cranks, so a young racer can turn it over out of the gate.

Specifications

Size: 20" wheels
Frame: 6061-T6 alloy, forged dropouts with internal chain tensioner
Top tube: 19.5"
Chainstay: 13.6"
Head tube angle: 73°
Seat tube angle: 71°
Bottom bracket height: 10.8"
Fork: Cr-Mo, 1-1/8" butted steerer, hi-ten fork legs, 23mm offset
Headset: FSA No.28 integrated, sealed, 1-1/8"
Stem: Radio Raceline Cobalt top loader, 50mm extension, alloy
Bars: 4130 Cr-Mo, seamless, 5.75" rise, 24.5" width, 8° backsweep, 2° upsweep
Grips: Radio Raceline Cobalt, diamond knurling, closed end, flangeless, 130mm
Brakes: Radio Raceline Mini V-brake, rear
Brake lever: Radio Raceline Junior, rear
Cranks: Radio Raceline Cobalt 3pc, forged alloy, 165mm
Bottom bracket: Radio Raceline, BSA square taper, sealed
Chainring: Radio Raceline, 42T, alloy
Chain: KMC Z6, 1/2" x 3/32"
Pedals: Radio Raceline Cobalt Pro, alloy
Front hub: Radio Raceline Cobalt, CNC alloy, fully sealed, 28H, 3/8" crmo axle
Rear hub: Radio Raceline Cobalt, CNC alloy, fully sealed, 28H, flip flop, 3/8" crmo axle
Rear cog: ATA freewheel, 16T, 1/2" x 3/32", crmo
Rims: Radio Raceline A-M5, double wall, 28H, alloy front and rear
Tyres: Arisun XLR8, 20" x 1-3/8"
Seat: Radio Raceline Cobalt Pro combo seat
Seat post: Radio Raceline, 25.4mm, alloy
Seat clamp: Radio Raceline, forged alloy
Gearing: 42 x 16, 54.08" ratio
Weight: 8.95kg

Assembly information

Your bike ships mostly assembled in the box. Finishing it takes most people 10 to 20 minutes with basic tools, and the video above walks through every step.

Fit the handlebars and line them up with the front wheel
Fit the front wheel, pedals and seat post
Check the brakes and tyre pressure before the first ride

Tools: Allen key set and a 15mm, 17mm or 19mm spanner for the pedals and axle nuts (bikes can vary between these three sizes). A socket is needed if installing pegs.

Rather have it done? Ask us about extra assembly before you order, or any local bike shop can finish the build for a small fee.

Radio Cobalt Expert Bike

Name: Radio Cobalt Expert Bike
Brand: Radio
SKU: RABK232-26-BLK
Price: 899.99 AUD
Availability: InStock
Rating: 5.0 (1 reviews)

Brand: Radio SKU: Click to copy the SKU and show the pick location

$899.99 AUD

Or 4 payments of $224.99 AUD with

Recommended Rider Height:

130-170cm

Colour - Black

Top Tube Length - 19.5

Race frames are sized by class, and the class you ride is set by rider height rather than age.

Size	Rider height	Top tube
Micro (18" wheels)	Under 120cm	16.25"
Mini (20" wheels)	110 to 140cm	17 to 18"
Junior	120 to 150cm	18.25 to 18.75"
Expert	130 to 170cm	19.5 to 19.75"
Expert XL	145 to 170cm	20 to 20.75"
Pro	150 to 175cm	20.25 to 20.75"
Pro XL	165 to 180cm	21 to 21.25"
Pro XXL	170 to 185cm and up	21.5 to 21.85"
Pro XXXL	175cm and up	22"
Pro XXXXL	180cm and up	22.5"
Cruiser (24" wheels)	175cm and up	21.5" and up

Heights overlap between classes on purpose. Where you land in two, a growing rider is usually better on the larger, and a rider who wants the bike to turn faster on the smaller. Some brands label the Pro size Pro L, with the same fit.

How to measure

Stand your rider against a wall in the shoes they ride in, heels flat, and mark the top of their head. Measure from the floor to the mark.

Between two sizes and still growing? Take the larger size.
Racing gates and wanting the bike to turn faster? Take the smaller size.
Top tube is the number that actually changes the fit, so compare it against the bike they ride now.

Not sure? Send us their height and we will tell you what we would put them on.

Read the full buying guide