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Versatility without compromise
Handcrafted road bike designed by you

Handcrafted Bikes designed by you

Handcrafted carbon fibre bikes fitted to you, designed by you and built for you. Crafted in Ireland, by our master frame builder, using the highest quality carbon fibre. FiftyOne will draw out, from your soul, your dream bike and make it a reality.

About us

Based in Dublin, Ireland, FiftyOne Bikes is a manufacturer of hand-built custom road bikes and factory-built gravel bikes. Every bike is made to our exacting standards and designed to the especially textured understanding we have of the needs of each individual rider.

FiftyOne Bikes was founded in 2016 by former international rider Aidan Duff, in response to the disappearance from top-end race bikes of the custom options that he had always enjoyed during his career.

Explore. Race. Shred. Tour.

The Assassin is a progressive gravel bike with a massive breadth of ability. Its adjustable geometry creates capability in place of compromise, allowing you to tailor the handling to how you ride. It’s exceptionally light, responsive and comfortable. In short, Assassin is the answer, whatever question your gravel riding asks.

Choose a bike for you

Frameset
EKAR 1x ENVE
EKAR 1X
SRAM FORCE AXS
GRX 800 2X
GRX 815 Di2 1X
GRX 815 Di2 2X
SRAM RIVAL 1X
GRX 600 1X

Spec

Frame

Frame material

BB

Fork

Headset

Handlebar

Stem

Seatpost

Front Derailleur

Rear Derailleur

Shift/brake levers

Brakes

Crankset

Cassette

Wheelset

Tyres

Saddle

3,499.00

Assassin Frameset

Assassin w/ variable geometry system, Fender and Rack Mounts, 12x142mm Thru-Axle

Toray Unidirectional pre-preg carbon T1100, 800 & 700 Fibres, High-modulus/high-strength performance layup

Trident w/ variable geometry system

FSA - 1-1/8 ( 45°/45° : 6/42mm) X 1-1/2 (36°/45° : 8/52mm)

7,499.00

EKAR ENVE

Assassin w/ variable geometry system, Fender and Rack Mounts, 12x142mm Thru-Axle

Toray Unidirectional pre-preg carbon T1100, 800 & 700 Fibres, High-modulus/high-strength performance layup

EKAR PRO-TECH T47 Threaded

Trident w/ variable geometry system

FSA - 1-1/8 ( 45°/45° : 6/42mm) X 1-1/2 (36°/45° : 8/52mm)

ENVE Gravel bar

Enve Stem

Enve Seatpost

None

Campagnolo Ekar 13 12-44T

Campagnolo Ekar Ergopower controls

Campagnolo Ekar flat mount hydraulic Disc w/ campagnolo 160mm rotors

Campagnolo Ekar 13s 38T

Campagnolo Ekar 13speed 9-42T

Campagnolo Shamal carbon disc

Michelin tyre power gravel 700 X 47c blk tlr

WTB SL8 cromoly black

6,499.00

EKAR 1X

Assassin w/ variable geometry system, Fender and Rack Mounts, 12x142mm Thru-Axle

Toray Unidirectional pre-preg carbon T1100, 800 & 700 Fibres, High-modulus/high-strength performance layup

EKAR PRO-TECH T47 Threaded

Trident w/ variable geometry system

FSA - 1-1/8 ( 45°/45° : 6/42mm) X 1-1/2 (36°/45° : 8/52mm)

Easton EA50ax flared to 16°

Zipp Service Course

Zipp Service Course 27.2

None

Campagnolo Ekar 13 12-44T

Campagnolo Ekar Ergopower controls

Campagnolo Ekar flat mount hydraulic Disc w/ campagnolo 160mm rotors

Campagnolo Ekar 13s 38T

Campagnolo Ekar 13speed 9-42T

Campagnolo Shamal carbon disc

Michelin tyre power gravel 700 X 47c blk tlr

WTB SL8 cromoly black

6,799.00

SRAM FORCE AXS

Assassin w/ variable geometry system, Fender and Rack Mounts, 12x142mm Thru-Axle

Toray Unidirectional pre-preg carbon T1100, 800 & 700 Fibres, High-modulus/high-strength performance layup

Enduro T47 Threaded Dub

Trident w/ variable geometry system

FSA - 1-1/8 ( 45°/45° : 6/42mm) X 1-1/2 (36°/45° : 8/52mm)

Easton EA70ax flared to 16°

Zipp Service Course

Zipp Service Course 27.2

None

Sram X01 axs

Sram Force eTap axs

Sram Force axs hrd flat mount w/ Centerline X Rotors (160mm)

Sram Force 1 axs 38T

Sram XG 1275 10-52T

DT Swiss DTG18 700c

WTB Riddler 45 x 700c (tan)

WTB SL8 cromoly black

4,999.00

GRX 800 2X

Assassin w/ variable geometry system, Fender and Rack Mounts, 12x142mm Thru-Axle

Toray Unidirectional pre-preg carbon T1100, 800 & 700 Fibres, High-modulus/high-strength performance layup

Enduro T47 Threaded 24mm

Trident w/ variable geometry system

FSA - 1-1/8 ( 45°/45° : 6/42mm) X 1-1/2 (36°/45° : 8/52mm)

Easton EA50ax flared to 16°

Zipp Service Course

Zipp Service Course 27.2

Shimano GRX RX810

Shimano GRX RX810 Medium cage shadow+

Shimano GRX RX810

Shimano GRX Flat Mount Hydraulic Disc w/ Shimano 160mm rotors

Shimano GRX RX810 48/31 11speed double

Shimano SLX M7000 11-34 11-speed

DT Swiss DTG18 700c

Pirelli Cinturato Gravel H classic 700 X 45c skinwall

WTB SL8 cromoly black

Contact us for availability

GRX 815 Di2 1X

Assassin w/ variable geometry system, Fender and Rack Mounts, 12x142mm Thru-Axle

Toray Unidirectional pre-preg carbon T1100, 800 & 700 Fibres, High-modulus/high-strength performance layup

Enduro T47 Threaded 24mm

Trident w/ variable geometry system

FSA - 1-1/8 ( 45°/45° : 6/42mm) X 1-1/2 (36°/45° : 8/52mm)

Easton EA50ax flared to 16°

Easton EA50

Easton EA70

Shimano GRX RX815

Shimano GRX RX815 short cage shadow+

Shimano GRX RX815

Shimano GRX Flat Mount Hydraulic Disc w/ Shimano 160mm rotors

Shimano GRX RX810-1 40T 11speed double

Shimano HG800 11-34 11speed

DT Swiss DTG18 700c

Pirelli Cinturato Gravel H classic 700 X 45c skinwall

WTB SL8 cromoly black

Contact us for availability

GRX 815 Di2 2X

Assassin w/ variable geometry system, Fender and Rack Mounts, 12x142mm Thru-Axle

Toray Unidirectional pre-preg carbon T1100, 800 & 700 Fibres, High-modulus/high-strength performance layup

Enduro T47 Threaded 24mm

Trident w/ variable geometry system

FSA - 1-1/8 ( 45°/45° : 6/42mm) X 1-1/2 (36°/45° : 8/52mm)

Easton EA50ax flared to 16°

Easton EA50

Easton EA70

Shimano GRX RX815

Shimano GRX RX815 short cage shadow+

Shimano GRX RX815

Shimano GRX Flat Mount Hydraulic Disc w/ Shimano 160mm rotors

Shimano GRX RX810-2 48/31T 11speed double

Shimano HG800 11-34 11speed

DT Swiss DTG18 700c

Pirelli Cinturato Gravel H classic 700 X 45c skinwall

WTB SL8 cromoly black

Contact us for availability

SRAM RIVAL 1X

Assassin w/ variable geometry system, Fender and Rack Mounts, 12x142mm Thru-Axle

Toray Unidirectional pre-preg carbon T1100, 800 & 700 Fibres, High-modulus/high-strength performance layup

Enduro T47 Threaded GXP

Trident w/ variable geometry system

FSA - 1-1/8 ( 45°/45° : 6/42mm) X 1-1/2 (36°/45° : 8/52mm)

Easton EA50ax flared to 16°

Easton EA50

Easton EA70

None

Sram Rival 1 long cage

Sram Rival 1

Sram Rival 1 hrd flat mount w/ Centerline X Rotors (160mm)

Sram Rival 1 38T

Sram XG 1150 Eagle 10-42T

DT Swiss DTG18 700c

WTB Riddler 45 x 700c (tan)

WTB SL8 cromoly black

Contact us for availability

GRX 600 1X

Assassin w/ variable geometry system, Fender and Rack Mounts, 12x142mm Thru-Axle

Toray Unidirectional pre-preg carbon T1100, 800 & 700 Fibres, High-modulus/high-strength performance layup

Enduro T47 Threaded 24mm

Trident w/ variable geometry system

FSA - 1-1/8 ( 45°/45° : 6/42mm) X 1-1/2 (36°/45° : 8/52mm)

Easton EA50ax flared to 16°

Zipp Service Course

Zipp Service Course 27.2

None

Shimano GRX RX812 Long Cage Shadow+

Shimano GRX RX600

Shimano GRX Flat Mount Hydraulic Disc w/ Shimano 160mm rotors

Shimano GRX RX600 40T single 11speed

Shimano SLX M7000 11-42 11 speed

DT Swiss DTG18 700c

Pirelli Cinturato Gravel H classic 700 X 45c skinwall

WTB SL8 cromoly black

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