Triathlon Aerobars: Aero vs Flat Handlebar and How to Choose Yours

Time trials are won in the position, and the position starts with the aerobars

On the bike leg of a triathlon or in a time trial, almost all the drag slowing you down isn't generated by the bike: it's generated by your body. That is why, before a more expensive frame, what really makes you faster is narrowing your frontal area and holding a comfortable aerodynamic posture for hours. And that is where triathlon aerobars come in.

The problem is that not all aerobars suit everyone or every bike. In this guide we explain the differences between mounting them on an aero handlebar or a flat handlebar, how to choose the right size and why making them to measure and in carbon completely changes the experience. If you want to cut to the chase, you can see all our models in the triathlon aerobars collection.

What are triathlon aerobars?

Aerobars (also called extensions or elbow rests) are the part mounted on the handlebar that lets you adopt the aero position: forearms resting, hands together out front and body low. That posture reduces the area the air meets head-on and, with it, the watts you need to ride at the same speed.

A race aerobar has three key areas: the elbow rest (where the forearm rests), the extension (the tube that goes forward) and the grip (where you place your hands). Getting the geometry of those three areas right is what separates a position you can hold for 10 minutes from one you can hold for a whole long-distance race.

Aero handlebar or flat handlebar: which is your case?

The most common question before buying is whether the aerobars will fit your bike. The short answer: there is a solution for both cases. The difference lies in how they are mounted and which discipline they are designed for.

If you ride a triathlon bike, the natural choice is to mount the aerobars on the aero handlebar. If your bike is a gravel, mountain or road bike with a flat handlebar and you want to gain aerodynamics for long rides or entry-level triathlons, aerobars for flat handlebars with their adapter are your option. In both cases you don't need to change handlebar.

How to choose your triathlon aerobars step by step

1. Length and elbow rest

Your forearm should rest naturally, without forcing you to hunch your shoulders or tense your neck. A well-sized elbow rest spreads pressure and prevents numbness over long distances.

2. Tilt and height

Our aerobars let you adjust the tilt from 0 to 35º and the height above the handlebar. This lets you fine-tune the angle until you find your point of maximum sustainable power, not just the lowest one.

3. Wrist angle and grips

The wrist works best at an angle close to 50º, which is how we design the hand position. You can also choose 35º or 50º grips depending on whether you prefer a more neutral or more aggressive posture.

4. Material

Carbon is king here: maximum stiffness (power isn't lost to flex) with minimum weight. Further down we tell you how we make it.

Why custom and carbon make the difference

Most aerobars on the market come in standard sizes: you adapt to them. At CarboXtrem it's the other way round: the aerobar adapts to you. Each unit is made according to your arm length and biomechanics, so the position is yours and not an average.

The aerobar structure is laid up by hand in Sato T1000-grade carbon fibre: stiff where it matters and very light. The adapters are made in carbon-fibre-reinforced nylon by 3D printing, which lets them be fitted to your handlebar to the millimetre. And the arm pads use EPU 41 resin, recognised by Carbon for its ability to absorb vibration and provide comfortable support for hours.

All of it made in Spain and backed by a lifetime warranty.

Wondering why the structure is laid up by hand instead of printed? We explain it in depth in our guide to hand-laid carbon vs 3D printing, where you'll see when we use each technology and why.

Compatible with all brands

Our aerobars are designed to fit all brands and models of handlebar, both aero and flat. If you have doubts about your specific cockpit, we advise you before manufacturing to ensure a perfect fit.

Quick summary

Frequently asked questions

Do triathlon aerobars work on a flat handlebar?

Yes. With the corresponding adapter they can be mounted on both aero and flat handlebars, without changing handlebar.

Are they made to measure?

Yes, each aerobar is made according to your arm length and biomechanics, with adjustable tilt and height.

What material are they made of?

The structure is laid up by hand in Sato T1000-grade carbon fibre; the adapters are 3D printed in carbon-reinforced nylon and the pads use EPU 41 resin.

Are they compatible with my bike?

They fit all brands and models. If in doubt, we advise you before manufacturing.

Find your triathlon aerobars

Whether you ride a triathlon bike or want to add an aero position to your gravel or road bike, we have an aerobar made to your measurements. Explore the full collection and step up to a truly efficient position.

See the triathlon aerobars →

Racing against the clock and want the pros' position? Also take a look at the Mantis System and the large-format arm rests.

Does your bike have a flat handlebar (gravel, MTB or road)? We have a dedicated guide to mounting aerobars on a flat handlebar.