A Fit Bike Co Misfit 18 Inch youth BMX bike in black with a brown seat, thick tires, and a gold accent on the right handlebar grip, displayed on a white background.

Close-up of the Fit Bike Co Misfit 18 Inch Bike in olive green, featuring a vibrant tiki face graphic on the head tube—an ideal choice for young BMX riders.

The Fit Bike Co Misfit 18 Inch Bike is a green youth BMX with yellow handlebars and tires, black seat, pedals, and front fork, plus a lightweight frame—all shown on a white background.

Close-up of a Fit Bike Co Misfit 18 Inch Bike tire mounted on a wheel, with "FITBIKECO/2.3" visible on the sidewall.

The Fit Bike Co Misfit 18 Inch Bike features a black frame with "FITBIKECO." branding, a brown seat, black handlebars with orange grips—perfect for kids seeking a stylish and high-performance BMX ride.

A side view of the Fit Bike Co Misfit 18 Inch Bike, a green youth BMX with black handlebars, seat, and wheels, tan sidewall tires, and yellow handlebar grips.

Close-up of the black Fit Bike Co Misfit 18 Inch Bike showing crank, chainring, pedal, and rear wheel—highlighting key details of this youth BMX model.

Description

FIT have kept the MISFIT line moving with team rider input and constant prototype testing, and the heart of it is carefully dialled geometry and proportionate sizing for young riders. For 2026 the 18" gets a lighter frame and a CNC-machined integrated head tube with threaded gyro tabs.

The fork has been lightened too, with a reduced 31mm rake and a welded insert that makes tensioning the headset easier. With more 18" bikes hitting the streets, FIT have moved to a larger 14mm x 170mm rear axle so pegs can go on.

Features

Sized right for younger riders. FIT build the MISFIT around dialled geometry and proportionate sizing, developed with team rider input and years of prototypes.
Lighter frame and fork for 2026. Less weight to lift and throw means a young rider gets more out of every session.
Wider 14mm x 170mm rear axle. Upgraded so the bike takes pegs, because plenty of 18" riders are now grinding on them.
CNC-machined integrated head tube. Threaded gyro tabs are built in, and the welded fork insert makes tensioning the headset easier.
Short reach lever, low tension springs. The U-brake is set up with a linear cable so smaller hands can pull it and stop without a fight.

Specifications

Size: 18"
Frame: Cro-Mo top and down tube
Top tube: 18"
Fork: Cro-Mo steerer, 31mm offset, welded insert
Headset: CNC-machined integrated with threaded gyro tabs
Stem: Mini top load
Bars: 2-piece, 8" x 27"
Brakes: U-brake with low tension springs, linear cable
Brake lever: Short reach
Cranks: Tubular Cro-Mo 145mm
Bottom bracket: Mid sealed
Sprocket: Fit Bite 24T
Pedals: Nylon platform 9/16"
Front hub: Unsealed, 36H
Rear hub: Sealed 9T cassette, 36H, 14mm x 170mm axle
Rims: 32mm single wall, 36H front and rear
Tyres: FIT OEM 2.3"
Seat: Flatter, more padded integrated combo, 25.4mm
Note: 14mm x 170mm rear axle to suit pegs

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.

Fit Bike Co Misfit 18 Inch Bike

Name: Fit Bike Co Misfit 18 Inch Bike
Brand: Fit Bike Co
SKU: FTBK104-26-BLK
Price: 949.99 AUD
Availability: InStock

Brand: Fit Bike Co SKU: Click to copy the SKU and show the pick location

$949.99 AUD

Or 4 payments of $237.49 AUD with

Colour - Gloss Black

Top Tube Length - 18

An 18 inch bike suits a rider of about 122 to 147cm, usually 7 to 11 years old, on an 18 to 18.5 inch top tube. It is the last step before a full size 20 inch.

Rider height	Wheel size	Top tube
60 to 91cm	12"	12 to 12.5"
81 to 106cm	14"	14 to 14.5"
96 to 122cm	16"	16 to 16.5"
122 to 147cm	18"	18 to 18.5"
147 to 157cm	20"	19.75 to 20.25"
157 to 168cm	20"	20 to 20.5"
168 to 175cm	20"	20.25 to 20.75"
175 to 183cm	20"	20.5 to 21"
183 to 190cm and up	20"	20.75 to 21.5"
160cm and up	22"	21 to 22.25"
160cm and up	24"	21.75 to 22"
160cm and up	26"	22 to 23"

Sizes overlap on purpose, so personal preference comes into it. If your rider is near 147cm and still growing, look at a 20 inch instead: it is the size they will keep riding.

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 an 18 and a 20? Take the 20. It is the size they will keep riding, and an 18 gets outgrown quickly.
They should be able to stand over the top tube with both feet flat on the ground.

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

Read the full buying guide