SIKA HEAD ON
SIKA SIDE SHOT
SIKA 45
SIKA HEAD SHOT CLOSE UP
SIKA BARS
SIKA REAR STAYS
SIKA HEAD TUBE
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ROAD

The new definition of the modern performance road bike

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GRAVEL

Versatility without compromise

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CUSTOM

Handcrafted road bike designed by you

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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.

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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.

Learn More >       Watch a Video >

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.

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Choose a bike for you

Download Assassin geo chart >

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  • SIKA SHIMANO ULTEGRA DI2

    7,500.00 € – 9,450.00 €
    Select options This product has multiple variants. The options may be chosen on the product page

  • SIKA SHIMANO DURA ACE DI2

    9,750.00 € – 12,000.00 €
    Select options This product has multiple variants. The options may be chosen on the product page

  • SIKA SRAM FORCE AXS

    8,250.00 € – 10,050.00 €
    Select options This product has multiple variants. The options may be chosen on the product page

  • SIKA SRAM RED AXS

    10,450.00 € – 12,500.00 €
    Select options This product has multiple variants. The options may be chosen on the product page

  • SIKA FRAMESET

    4,499.00 €
    Select options This product has multiple variants. The options may be chosen on the product page
  • Out of Stock OG-2

    OG-2 LIMITED EDITION

    4,499.00 € – 8,499.00 €
    Contact us for availability

  • Framesets

    3,499.00 €
    Select options This product has multiple variants. The options may be chosen on the product page

  • EKAR 1x ENVE

    7,499.00 €
    Select options This product has multiple variants. The options may be chosen on the product page
  • Sale

    EKAR 1X

    Original price was: 6,499.00 €.Current price is: 4,499.00 €.
    Select options This product has multiple variants. The options may be chosen on the product page
  • Sale

    GRX 800 2X

    Original price was: 4,999.00 €.Current price is: 4,499.00 €.
    Select options This product has multiple variants. The options may be chosen on the product page
    • Compare
    Framesets
    EKAR 1x ENVE
    EKAR 1X
    GRX 800 2X
    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)

    Contact us for availability
    Contact us for availability

    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

    Original price was: 6,499.00 €.Current price is: 4,499.00 €.

    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

    Original price was: 4,999.00 €.Current price is: 4,499.00 €.

    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

    WTB Riddler 45 x 700c (tan)

    WTB SL8 cromoly black

    Original price was: 4,499.00 €.Current price is: 3,999.00 €.

    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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