Author Ultrasonic 24

2026 YouthRoad youth Manufacturer page

Suspension: Rigid
Wheels: 24″
Drivetrain: 1 × 8 32t / 11–40t
Gear range: 364%
Weight: 9.7 kg 21.4 lb · Reference configuration not specified
Frame: Aluminum
Brakes: Rim brake

Rider height by size (cm)

Size guide

12" 125–140

Components

11 of 18 identified

Parts found in a manufacturer catalog show their brand, model and key numbers, and the steps show how precisely they are identified: brand, series, model, or the exact product. The info button has every detail and the text the manufacturer published.

Frame and fork

1 part

Frame

triple butted hydroformed alloy 6061 24" Not identified

Suspension

1 part

Fork

alloy 6061 24" Not identified

Drivetrain

5 parts

Cassette
- Shimano CS-HG400-8 8 speeds
CS-HG400
Chain
- KMC Z8.3 8 speeds
Crankset
- Prowheel
Rear derailleur
- Shimano Acera
Shifters
- Shimano Acera

Brakes

1 part

Brakes
- Tektro

Wheels and tires

5 parts

Front hub

QUANDO, 24 holes Not identified
Rear hub

QUANDO, 24 holes Not identified
Rims

alloy, 24 holes Not identified
Spokes

black stainless steel 2.0 mm Not identified
Tires
- Kenda Small Block Eight

Cockpit and contact points

5 parts

Handlebar
- Author
Pedals

plastic Not identified
Saddle
- Author
Seatpost
- Author
Stem
- Author

Sizes and geometry

1 size Open in the geometry plotter

Enter your height to highlight matching ranges.

Size 12"

Table

Reach 359mm

Stack 463mm

Wheelbase 965mm

Head angle 70.0°

Seat angle 73.0°

Every size is drawn to the same scale, in millimeters. Explanatory schematic on an assumed 24″ wheel; exact published values are in the table below.

Size Reported by the manufacturer

Complete manufacturer geometry table 1 published size

Complete manufacturer geometry by size
Measurement
Reachmm	359
Stackmm	463
Top tube lengthmm	500
Seat tube lengthmm	305
Head tube lengthmm	110
Head tube angle	70°
Seat tube angle	73°
Chainstay lengthmm	400
Wheelbasemm	965
Front centermm	566
Bottom bracket dropmm	25
Fork rakemm	45
Stack/reach ratio	1.29

Not published by the manufacturer: Bottom bracket height, Standover height, Trail, Front travel, Rear travel, Crank length, Handlebar width, Stem length, Stem angle, Seatpost length and Dropper post travel.

Specifications

Frame and fork

Intended fit: Unisex
Frame material: Aluminum
Fork material: Aluminum
Bicycle weight: 9.7 kg

21.4 lb

Suspension

Suspension configuration: Rigid

Drivetrain

Derived by Bikelake

Front chainrings: 1
Smallest chainring: 32
Largest chainring: 32
Rear sprockets: 8
Smallest sprocket: 11
Largest sprocket: 40
Lowest gear: 19.2 in
Highest gear: 69.8 in

Wheels and brakes

Wheel configuration: Same size
Brake type: Rim brake

Fit and controls

Seatpost: Rigid seatpost
Shifting: Mechanical

Additional specifications

Tire width: 1.95″
Wheel material: Aluminum
Wheel size: 24″

Gearing

Estimated speeds at 80 rpm

Lowest gear: 7.4 km/h
Highest gear: 26.7 km/h

Total gear range 364%

Technical details and class reference

These speeds describe the gearing at the selected cadence, not how fast you can ride.
Calculated from published gear-inch values and their wheel-size assumptions.
These gearing values describe the bicycle, not a selected frame size.
A 100% range means one ratio; 500% means the highest ratio is five times the lowest.
For e-bikes, motor assistance cutoff is not represented.

Gear-inch range

Lower gear-inch values travel less distance per pedal revolution; higher values travel farther.

This bicycle: 19.2–69.8 gear inches

Lineup changes

The published facts that differ across this family's builds and from the same model a year earlier. Missing information never counts as zero.

Differences across 2026 builds
Specification	This bicycle Author Ultrasonic 24	Author Ultrasonic 26	Author Ultrasonic 27.5
Frame
Fork material	Aluminum	Aluminum	Not informed
Bicycle weight	9.7 kg	10.8 kg	12.5 kg
Suspension
Suspension configuration	Rigid	Rigid	Hardtail
Front travel	Not informed	Not informed	80 mm
Drivetrain
Rear sprockets	8	Not informed	Not informed
Largest sprocket	40	48	50
Lowest gear	19.2 in	17.3 in	17.6 in
Highest gear	69.8 in	75.6 in	80.0 in
Brakes
Brake type	Rim brake	Hydraulic disc	Hydraulic disc
Other specifications
Suspension	Rigid	Rigid	Hardtail
Tire width	1.95″	2.1″	2.25″
Wheel size	24″	26″	27.5″
Fork spring	Not informed	Not informed	Air