AUTHOR Ultrasonic 27,5 2021-22 - tripple butted alloy frame

AUTHOR Ultrasonic 27,5 2021-22Tripple butted alloy frame  |  RST F1RST air fork  |  SHIMANO Deore groupset

Ultralight junior racing special on 27.5 inch wheels. If you are looking for the best in given category for your rider, this is the right choice! Very light alloy frame made of triple butted tubes, shaped by hydroforming technology, which guarantees strong and very durable process with minimal weight. RST air fork, SHIMANO Deore components, 11 speeds, TEKTRO hydraulic disc brakes with excellent braking performance. A machine that will definitely not be bored on the race route, but will also be a perfect buddy on any trip!
AUTHOR Ultrasonic 27,5 2021-22
Interested in other model`s year?

Technical specification

Size14", 16"
Frametriple butted hydroformed alloy 6061 27.5"
Front forkRST F1RST 27.5 air, lock out (80 mm)
Head partsAUTHOR Integrated 1.5" tapered
Chain WheelPROWHEEL 32 teeth 165 / 170 mm cranks
Rear derailleurSHIMANO SLX
ShiftersSHIMANO SLX (11)
Free wheelSHIMANO M5100-11 11-51 (11)
ChainKMC X11
HubsAUTHOR Xenon 32 holes
BrakesTEKTRO Gemini disc hydraulic (6" rotors)
Brakes leversTEKTRO Gemini WS
RimsAUTHOR Xenon TRC 27.5 32 holes
Spokesblack stainless steel 2.0 mm
TiresCST B-Trail aramid 27.5" × 2.25"
HandlebarAUTHOR Flat Top bar 9° 620 / 640 mm
GripsAUTHOR kratton rubber
StemAUTHOR alloy
Seat postAUTHOR alloy (31.6)
Seat clampAUTHOR (34.9)
SaddleAUTHOR Champion Author Navigator
Weight11,5 kg / 16"

Geometry and sizes

Size 14" 16"
Min. figure [cm] 140 155
Max. figure [cm] 158 170
S/T c-t [mm] 356 406
S/T c-c [mm] 0 0
T/T h [mm] 550 575
T/T a [mm] 544 557
H/T [mm] 110 115
C/S [mm] 420 420
W/B [mm] 1052 1067
S/T ang. [°] 74 73.5
H/T ang. [°] 69 69.5
F/L [mm] 475 475
B/B drop [mm] 45 45
B/B width [mm] 73 73
Reach [mm] 0 0
Stack [mm] 0 0
F/R [mm] 43 43
Handlebars [mm] 0 0
Stem [mm] 0 0
Cranks [mm] 0 0
max min
AUTHOR Ultrasonic 27,5 2021-22

The recommended size and stature are just indicative. It is recommended to always consult your choice with the dealer.

  • S/T c-t - seat tube (center-top), length of the seat tube from the middle of BB parts to its peak
  • S/T c-c - seat tube (center-center), length of the seat tube from the middle of BB parts to an axle of the upper tube
  • T/T h - top tube horizontal, horizontal lenght of the upper tube
  • T/T a - top tube actual, real lenght of the upper tube
  • H/T - head tube, head tube lenght
  • C/S - chain stay, chain brace lenght
  • W/B - wheel base, wheelbase (front and rear axle lenght)
  • S/T ang. - seat tube angel, angle between the seat tube axis and an imaginary line connecting the axes of the front and rear wheel
  • H/T ang. - head tube angel, angle between the head tube axis and an imaginary line connecting axes of the front and rear wheels
  • F/L - fork length, fork length from the head parts bottom to the middle of the front wheel
  • B/B drop - bottom bracked drop, lenght between an imaginary line connecting wheels centers and BB parts, measured from BB parts
  • F/R - fork rake, distances between the head tube axis and fork axis measured at center of the front wheel, so-called. off set


AUTHOR Ultrasonic 27,5 2021-22


Product options

lime / blue14" = UA#42933200   16" = UA#42933201