Author Ultrasonic 27.5

2026 YouthRoad youth Manufacturer page

Fork travel: 80 mm
Wheels: 27.5″
Gear range: 455%
Weight: 12.5 kg 27.6 lb · Reference configuration not specified
Frame: Aluminum
Brakes: Hydraulic disc

Rider height by size (cm)

Size guide

14" 140–158
16" 155–170

Components

15 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 27.5" Not identified

Suspension

1 part

Fork
- RST

Drivetrain

5 parts

Cassette
- Shimano CS-LG400-11 11 speeds
CS-LG400-11
Chain
- KMC XGlide 11 speeds
Crankset
- Prowheel
Rear derailleur
- Shimano Cues RD-U6000 11 speeds
RD-U6000
Shifters
- Shimano Cues SL-U6000
SL-U6000

Brakes

1 part

Brakes
- Tektro HD-M530
HD-M530

Wheels and tires

5 parts

Front hub
- Author
Rear hub
- Author
Rims
- Author
Spokes

black stainless steel 2.0 mm Not identified
Tires
- CST

Cockpit and contact points

5 parts

Handlebar
- Author
Pedals

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

Sizes and geometry

2 sizes Open in the geometry plotter

Enter your height to highlight matching ranges.

Size 14"

Table

Reach 385mm

Stack 575mm

Wheelbase 1052mm

Head angle 69.0°

Seat angle 74.0°

Every size is drawn to the same scale, in millimeters. Explanatory schematic on an assumed 27.5″ wheel; exact published values are in the table below.

Size Reported by the manufacturer

Complete manufacturer geometry table 2 published sizes

Complete manufacturer geometry by size
Measurement
Reachmm	385	403
Stackmm	575	582
Top tube lengthmm	550	575
Seat tube lengthmm	356	406
Head tube lengthmm	110	115
Head tube angle	69°	69.5°
Seat tube angle	74°	73.5°
Chainstay lengthmm	420	420
Wheelbasemm	1052	1067
Front centermm	636	651
Bottom bracket dropmm	45	45
Fork rakemm	43	43
Stack/reach ratio	1.49	1.44

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
Bicycle weight: 12.5 kg

27.6 lb

Suspension

Suspension configuration: Hardtail
Front travel: 80 mm

Drivetrain

Derived by Bikelake

Front chainrings: 1
Smallest chainring: 32
Largest chainring: 32
Smallest sprocket: 11
Largest sprocket: 50
Lowest gear: 17.6 in
Highest gear: 80.0 in

Wheels and brakes

Wheel configuration: Same size
Brake type: Hydraulic disc

Fit and controls

Seatpost: Rigid seatpost
Shifting: Mechanical

Additional specifications

Fork spring: Air
Tire width: 2.25″
Wheel material: Aluminum
Wheel size: 27.5″

Gearing

Estimated speeds at 80 rpm

Lowest gear: 6.7 km/h
Highest gear: 30.6 km/h

Total gear range 455%

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