Advanced Aerodynamic & Ergonomic Extensions for Time Trial & Triathlon


Choose the length, angle and spec. to best suit you


The latest advanced manufacturing technology is used to make every set of ProngZ


Smash your goals with the improved aerodynamics and stability offered by ProngZ

The most advanced aero extension system for your bike. Customisable class leading design, without the cost. ProngZ offer the rider a more aerodynamic, stable, and refined system for their TT / Triathlon Bike.


The base design has been established from the ground up, for aerodynamics, adjustability and wide ranging compatibility, with all athletes in mind.

Advanced Manufacturing

Using the latest technology in advanced manufacturing - each set are custom made from a carbon fibre infused polyamide matrix that is further strengthened internally with continuous fibreglass. This results in extensions that are both light and strong, meeting the safety requirements for ISO 4210.

Razor Arm Rests

ProngZ extensions are paired with ProngZ specific Razor arm rests, which are unique for every customer. Designed specifically to integrate the ProngZ to your forearms. No matter what size your forearms are, a snug, comfortable and supportive fit will be achieved.

These arm rests are made from the engineering polymer - polycarbonate. The unique design which mates the armrests to the extensions results in incredible strength, whilst also having slight flex to cushion your ride.


Despite being a rigid integrated extension, there is a huge range of adjustment built into the system: The supplied Universal Dual Stack Mounting Plates provide 72 different fit options, with both longitudinal and lateral adjustment of the extensions' position. There are also 6 degrees of toe angle adjustment (hands closer or further apart).

In addition, the Razor arm rests can move up and down the extension for even more adaptability,  whilst ensuring the extension body always remains in line and snug to your forearm.

ProngZ are supplied with a choice of three sets of handles: 40 degrees, 57.5 degrees and 75 degrees, so that you can fine tune your fit. Typically the steepest angle are more comfortable due to a more neutral wrist angle, while the shallowest angle help fit within the UCI 10 cm regulation.


Full internal cable routing for either mechanical or electronic shifters.

Dedicated Garmin or Wahoo mount included. Choose from a range of different widths and heights, designed for maximum visibility and functionality in different riding positions.


The ProngZ are currently compatible with any dual stack tower handlebar system or the older rim brake Trek Speed Concept using our own dedicated adapter mount.

UCI Compliance

ProngZ can be customised to meet the UCI regulations. See below for how to design your system.


Design Your ProngZ

Customise your extensions in 4 simple steps.

Step 1


Step 2


Step 3

Arm Rests

Step 4


Step 1: Length

Measurement in millimetres from the centre line between the two stacker tower screws, to your wrist knuckle. The measurement should be parallel to your arm. See image below. The best way to measure this is to use a tape measure - carefully place the start of the tape measure at the point where the centre line between the two stacker tower screws would intersect arm rest - place your arm on the arm rest, such that the tape is between the arm rest and your arm - then take a measurement to your wrist knuckle. ProngZ can achieve lengths between 165 mm minimum and 260 mm maximum.

Step 2: Angle

This defines the rise angle of the main extension body, excluding handle. This is also the angle of the armrests. See image below. We offer two standard base angle options: 14 degrees (UCI legal) and 25 degrees (non UCI events eg CTT and Triathlon). However this base angle can be fine tuned using our supplied extension wedges in 2 degree increments up to +/-6 degrees. This means ProngZ can achieve any angle between 8 and 31 degrees. This extension rise angle gives a different effect to traditional extension pole angles. The ProngZ angle of 14 degrees with the 40 degree handle, would typically correspond to around a reversed 30 degree set up using traditional extension poles. 25 degrees ProngZ with the 40 degree handle, correspond roughly to high rise reversed 40 degree traditional extensions.


If you require to be UCI legal, you must choose an extension angle less than or equal to 15 degrees, to ensure your arm rest inclination does not exceed 15 degrees maximum limit, in compliance with the UCI regulations.

We would recommend an angle of 14 degrees and to not use the steepest 75 degree hand grips, as these contribute more vertical height towards the 10 cm rule. In the majority of cases, a 14 degree angle, with the 40 degree hand grip and mid range arm rest position would result in a UCI compliant position. A more foreward armrest position may allow the use of the 57.5 degree handles, depending on the length of the shifter/bar end installed. However it is the responsibility of the rider to ensure their ProngZ set-up meet the UCI regulations.


Step 3: Arm Rests

If choosing the Razor arm rests, we simply require the circumference (in mm) of your forearm at the thickest point. Use a tailor's tape measure as seen in the image below. Apply a little tension to the tape around your arm.


Step 4: Mounting

For dual stack tower system, like the one below, we require the following: 1) Stacker Screw spacing; 2) Stacker Tower Spacing; 3) Screw type M5/M6; 4) Screw direction - do the screws for the stackers "Screw Down" into the base bar or "Screw Up" from the base bar (image below shows a "Screw Up" type). - We have our own dedicated adapter plate for use with Trek Speed Concept.


The measurements and specifications mentioned above need to be included in the product shop page when purchasing your ProngZ

...Step 5: Don't Panic!


The ProngZ extensions system is designed such that the customisation process gets your fit in the right ball park, the high adjustability of the ProngZ enables you to fine tune it on the bike.


If you need any help, please don't hesitate to drop us a message. We will make every effort to ensure the extensions are right for you. We may contact you to get more information, measurements, or some photos of your bike set-up to ensure we get your ProngZ right for you.