The Profile Design 39a Aluminium Extensions are designed around modern high-hand aerobar positioning, offering a 39° grip angle to create a comfortable and sustainable hand position while maintaining an aerodynamic posture. The shape allows riders flexibility in how they position their hands — holding higher can encourage a more shrugged aero position, while a lower grip creates a more open posture with improved visibility and head position.

To further fine-tune fit, the 39a incorporates a small lateral offset, allowing riders to narrow or widen hand position without excessive extension rotation. This can improve comfort and achieve cleaner hand positioning without compromising shifter clearance.

Additional aerodynamic shaping has been incorporated into the rise section, while ergonomic end caps improve hand comfort during longer rides and races.

Compatible with any aerobar system designed around a standard 22.2 mm clamp diameter.

Ideal for: riders chasing a modern high-hand position with flexibility to refine comfort, aerodynamics and hand placement.

Bike Fit Note: Extension shape and angle can significantly affect comfort, shoulder position and aerodynamics. The ideal extension is highly individual and recommendations are included as part of my bike fitting process.

Specs

• Construction: 6061-T6 aluminum, pre-drilled for bar-end shifter cable routing

• Extension Length: 400mm

• Extension Angle: 39 Degrees

• Extension Rise: 87mm (bottom to top)

• Extension Offset: 15mm total

• Outer Diameter: 22.2mm

• Inner Diameter: 19.2mm

• Shifter Compatibility: Electronic or Mechanical

• Includes: Sold as a Pair (1 Right and 1 Left Extension)

• Colors: Anodized Matte Black

• Weight: 206g/pair

• Min Length: mm (from the front of clamp)

The Profile Design 52 ASA Aluminium Extensions are designed around modern high-hand aerobar positioning, featuring a 52° grip angle combined with a shaped design that follows the natural position of the arms. By incorporating a lateral offset into the extension itself, the 52 ASA creates a more natural arm and hand alignment while maintaining compatibility with standard 22.2 mm aerobar systems.

This shaped design helps riders achieve a narrow and supported position without requiring excessive extension rotation, improving comfort and creating a cleaner front-end setup. The higher hand position can also assist riders in achieving a more relaxed and aerodynamic posture during longer efforts.

Constructed from aluminium using an advanced forming process, the 52 ASA delivers the fit benefits of shaped extensions in a durable and cost-effective package. Ergonomic end caps further improve comfort at the hand contact point during training and racing.

Compatible with any aerobar system designed around a standard 22.2 mm clamp diameter.

Ideal for: riders seeking a modern high-hand position with improved arm alignment, support and long-distance comfort.

Bike Fit Note: Extension shape can significantly influence comfort, shoulder posture and aerodynamic sustainability. Different hand angles and shapes suit different riders, with recommendations included as part of my bike fitting process.

Specs

• Construction: 6061-T6 aluminum, pre-drilled for bar-end shifter cable routing

• Extension Length: 340mm or 400mm

• Min Length: 340mm: 225mm or 400mm: 285mm (from the front of clamp)

• Extension Angle: 52 Degrees

• Extension Rise: 137mm (bottom to top)

• Extension Offset: 16mm total

• Outer Diameter: 22.2mm

• Inner Diameter: 19.2mm

• Shifter Compatibility: Electronic or Mechanical

• Includes: Sold as a pair (1 Right and 1 Left Extension)

• Colors: Anodized Matte Black

• Weight: 400mm: 304g/pair or 340mm: 250g/pair

The Profile Design 45/25 SLC Carbon Extensions are designed to provide multiple hand position options while maintaining a lightweight, high-performance setup. Featuring a dual-angle design with a 45° rise transitioning into a 25° grip section, riders can comfortably hold the extensions higher for a shrugged aerodynamic position or lower for a more open posture with improved head position and visibility.

A subtle lateral offset built into the extension allows hand position to be adjusted narrower or wider without excessive extension rotation, helping maintain cleaner positioning and avoid shifter interference.

Constructed using Profile Design’s Super Light Carbon technology, the 45/25 SLC combines reduced weight with improved integration, including compatibility with Aeroport Di2 adaptors for a cleaner electronic shifting setup. Ergonomic end caps further enhance comfort during long training sessions and race efforts.

Compatible with any aerobar system designed around a standard 22.2 mm clamp diameter.

Ideal for: riders wanting a lightweight extension with flexibility in hand position and modern high-hand fit options.

Bike Fit Note: Extension angle can significantly influence comfort, shoulder posture and aerodynamic sustainability. Multi-position designs can be particularly useful when fine-tuning a position or balancing comfort with performance.

Specs

• Extension Length: 400mm

• Extension Angle: 45 Degrees / 25 Degrees 

• Outer Diameter: 22.2mm

• Includes: Sold as a Pair (1 Right and 1 Left Extension)

• Construction: Carbon

• Colors: Matte Black

• Weight: 70g/pair

The Profile Design 43 ASC Carbon Extensions are designed to combine aerodynamic performance, comfort and support into a highly refined extension system. Built using Aero Shaped Carbon technology, the shaped profile takes advantage of carbon’s ability to create complex forms that improve airflow while maintaining excellent strength and stiffness.

Featuring a 43° grip angle and an 87 mm rise, the 43 ASC is designed to place the wrists in a more neutral position, helping riders relax into a comfortable and sustainable aero posture. A relaxed upper body often leads to improved comfort, reduced tension and a position that can be maintained more effectively over long distances.

The wrist and forearm area has been shaped to increase support and contact area, improving stability and comfort while also smoothing airflow around the rider. The design has been refined to balance aerodynamic performance with control and long-duration comfort.

Pairs particularly well with Race+ and Ergo+ armrests to create a highly supportive front-end setup.

Compatible with any aerobar system designed around a standard 22.2 mm clamp diameter.

Ideal for: riders seeking a premium aerodynamic extension with increased support, improved comfort and a modern high-hand position.

Bike Fit Note: Hand position and support can have a significant impact on comfort, shoulder posture and aerodynamic sustainability. Small changes at the contact points often create some of the biggest gains in long-course comfort and performance.

Specs

• Extension Length: 340mm or 400mm

• Min Length: 290mm (from the front of clamp)

• Extension Angle: 43 Degrees

• Extension Rise: 107mm (bottom to top)

• Extension Offset: 16mm total

• Outer Diameter: 22.2mm

• Inner Diameter: 

• Includes: Sold as a Pair (1 Right and 1 Left Extension)

• Construction: Carbon

• Colors: Matte Black

• Weight: g/pair