Author Ultrasonic 27.5

2019 YouthRoad youth Manufacturer page

Fork travel: 80 mm
Wheels: 27.5″
Drivetrain: 1 × 11 32t / 11–46t
Gear range: 418%
Weight: 11.8 kg 26.0 lb · Reference configuration not specified
Frame: Aluminum
Brakes: Hydraulic disc

Rider height by size (cm)

Size guide

14" 140–158
16" 155–173

Components

16 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 26" Not identified

Suspension

1 part

Fork
- RST

Drivetrain

5 parts

Brakes

1 part

Brakes
- ProMax

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

Sizes and geometry

2 sizes Open in the geometry plotter

Enter your height to highlight matching ranges.

Size 14"

Table

Geometry diagram unavailable

The drawing needs reach and stack, which the manufacturer did not publish. Available facts remain in the table.

Size Reported by the manufacturer

Complete manufacturer geometry table 2 published sizes

Complete manufacturer geometry by size
Measurement
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

Not published by the manufacturer: Reach, Stack, Bottom bracket height, Standover height, Trail, Stack/reach ratio, 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: 11.8 kg

26.0 lb

Suspension

Suspension configuration: Hardtail
Front travel: 80 mm

Drivetrain

Derived by Bikelake

Front chainrings: 1
Smallest chainring: 32
Largest chainring: 32
Rear sprockets: 11
Smallest sprocket: 11
Largest sprocket: 46
Lowest gear: 19.1 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: 7.3 km/h
Highest gear: 30.6 km/h

Total gear range 418%

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: 19.1–80.0 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 2019 builds

Differences across 2019 builds
Specification	This bicycle Author Ultrasonic 27.5	Author Ultrasonic 24	Author Ultrasonic 26
Frame
Bicycle weight	11.8 kg	9.8 kg	10.5 kg
Fork material	Not informed	Aluminum	Aluminum
Suspension
Suspension configuration	Hardtail	Rigid	Rigid
Front travel	80 mm	Not informed	Not informed
Drivetrain
Rear sprockets	11	9	11
Largest sprocket	46	36	42
Lowest gear	19.1 in	21.3 in	19.8 in
Highest gear	80.0 in	69.8 in	75.6 in
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″