Anemoi Mk2 Extension System (Dual Riser Stack)

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Build Guide Install Guide


Introducing the Anemoi Mk2 Extension system – the evolution of cycling extension excellence. Building upon the original Anemoi extensions that set the industry standard, we've taken innovation to the next level with our latest iteration.

In response to the ever-changing UCI regulations and the evolving needs of triathletes, we've gone back to the drawing board to refine and optimise the original Anemoi design. The result is Anemoi Mk2 – a product that stays true to the essence of its predecessor while introducing ground-breaking features and advancements.

With Anemoi Mk2, we continue our commitment to evolution, not revolution.

For guidance on how to select your components, please consult our Build Guide.

Technical Specifications


The Anemoi aero extensions have been tested to ISO standard ISO 4210-5:2014, the safety standard for bicycle steering components. The full test report is available here.


Extension body: 492g
Arm rests: 171g (single-sided)
Foam padding: 22g
Handgrip: 94g
Adjustable angled riser: 96g
Computer mount: 23g 
SYSTEM WEIGHT:  898g (pair)

Mount plate: 120g
Conversion spacer: 58g (3T Aduro)

What's included

A full system comprises of the following.

Core Items:
1x pair of extensions
1x pair of specified handgrips
1x pair of specified armrests

Build specific items:
Standard - 1x pair of adjustable risers (inc riser collar), 1x single computer mount

Anemoi Basebar - 1x pair of adjustabe risers (inc collar) or fixed angled risers, 1x crossbrace computer mount

Conversion Kit - 1x pair of adjustabe risers (inc collar) or fixed angled risers, 1x crossbrace computer mount, 1x pair of conversion spacers

Mount Plate - 1x pair of adjustabe risers (inc collar) or fixed angled risers, 1x single computer mount, 1x pair of short mount plates, 1x pair of long mount plates.

All required mounting hardware, included.
More information can be found on each components page; arm rests, angled risers, mount plates, handgrips and computer mounts.

Why we created Anemoi Mk2

The Anemoi Mk2 Extension System is a testament to our dedication to evolutionary progress rather than abrupt revolution. Rooted in extensive research and customer feedback, numerous upgrades have been meticulously crafted to enhance every aspect of the system. From versatile mounting solutions and robust hardware to updated profile designs and numerous handgrip options, the Mk2 upgrades are abundant.

Amidst the refinements introduced across various aspects of the Mk2 System, certain features endure. The highly sought-after Anemoi Adjustable Riser, favoured by those valuing customisation, retains its prominent place. Additionally, the Anemoi Carbon arm rests, renowned both as standalone items and integral components of the Anemoi system, persist with subtle tweaks aimed at achieving the optimal position.

For more details on the latest system enhancements, refer below or delve into our performance blogs to explore the ongoing evolution of the Anemoi System.

Dual Stack Mounting Options

The Anemoi Mk2 Extension System boasts compatibility with a wide range of industry-leading basebars. Opting for the Standard Mount enables direct installation onto the existing riser stack. To ensure compatibility, your system requires a flat-topped riser stack with bolt centres between 15-40mm. For further guidance, please consult our compatibility guide where you will find a comprehensive list of compatible bike models.

Please note, due to the fixed 40mm bolt hole centres required for installation, the Fixed Angled Riser is not compatible with the Standard Mount option, Adjustable Angled Risers are provided instead. Our new Riser Collars are included with the system and facilitate seamless integration between the Adjustable Riser and the Extensions.

The Anemoi Mk2 Extension System seamlessly integrates with the Anemoi Basebar, delivering a TT Cockpit renowned for its unparalleled aerodynamic performance.

If you're planning to mount the Mk2 System onto your existing Anemoi basebar, please select this option when choosing your components.

Designed to facilitate effortless integration between the Anemoi Mk2 System and third-party basebars where the riser stack is not flat, Anemoi Conversion Spacers ensure seamless compatibility and integration, whilst optimising the alignment of your riser stack lateral centres.

Initially offered for select market-leading bike frames, this collection is rapidly expanding.

The Mount Plate option provides extensive reach and width adjustment windows, catering to a wide range of riding positions.

Mount Plates guarantee riders the flexibility to tailor their setup to their individual preferences and requirements, whether they prefer a compact or extended riding position.

Short and long plates are included as standard.

New Features

Extension Profile

Taking advantage of recent UCI regulations, our widened 46mm cross-section extension profile provides enhanced forearm support while simultaneously reducing drag resulting from boundary layer separation. Wider extension profiles consistently tested faster in the wind tunnel and velodrome. The Mk2's aggressive new wrist kink also minimises the gap between the extension and wrist, mitigating localised flow turbulence.

Handgrip Options

Introducing the Anemoi Mk2 interchangeable handgrip collection to suit various shifting systems. A sophisticated two-piece design with integrated satellite shifters, these grips optimise shifter contact area. The expanded contact surface ensures effortless shifting, whether using your index finger, little finger, or a full palm grip. An enlarged handgrip hardpoint offers greater access to the extension for junction boxes and cables. Please check our Build Guide to ensure UCI compliance.

Conversion Spacers

Complementing the Anemoi Mk2, we are proud to unveil our latest innovation: a lineup of conversion spacers. Designed for seamless integration with a variety of basebars, these spacers ensure a tidy fit while maintaining optimal lateral centres. Initially available for select basebars, our collection is swiftly expanding to accommodate a broader range of models.


Retaining all of the adjustability of its predecessor, the Mk2 System now offers up to 35mm of reach adjustment, while our redesigned Puck allows for up to 5º of toe-in and 10mm of lateral width adjustment for a truly tailored fit. A more elevated extension angle in front of the armrest provides superior forearm support and a more ergonomic high-hands position.

Reduced Stack

By reducing the stack height under the armrest by 4.5mm, we've achieved significant gains in aerodynamic efficiency. Additionally, the option to remove the mount plates allows for a total possible stack height reduction of up to 12.5mm. This not only streamlines the profile for enhanced aerodynamics but also offers greater customisation options, allowing riders to achieve their ideal fit with precision.

Computer Mount

The Mk2 System debuts two new Computer Mount designs. A single-sided option suited to uncontrolled lateral centres introduces toe adjustment and allows you to align your Garmin or Wahoo irrespective of the extension toe angle. The cross-brace version is also available and suited to the Anemoi Basebar and Conversion Spacer mount options. This innovative design centralises the head unit and creates a sturdy bridge between extensions.

Fixed Angle Risers

Pushing the boundaries of integration, our Fixed Angle Risers represent a new chapter in WattShop's product design innovation.

Available in 5º increments ranging from 10º to 30º, these fixed risers seamlessly integrate the extension arm with the mounting stack.

We recommend fixed angled risers for athletes who have either locked in their riser angle or are looking to maximise their riser angle within UCI regulations.

Improved aerodynamic performance

Through exhaustive CFD, wind tunnel and velodrome testing, the Mk2's broader extension profile consistently showcased aerodynamic superiority, yielding repeated improvements in CdA.

After evaluating numerous profile designs, the ultimate Mk2 iteration, represented by Profile F in the graph below, emerged as the top performer on average. While certain profiles may have surpassed it for individual riders, our comprehensive testing consistently demonstrated that the selected profile exhibited superior performance across various conditions and riders. The significant enhancements compared to the Mk1 system can be seen below. Please check out our Performance Blogs for more information about the testing process.