Large-Format Triathlon Arm Rests: Why Your Forearm Decides Your Long-Distance Race (and the Pad Changes Everything)

The point that holds up your whole aero position (and almost nobody looks at)

In a long time trial or the bike leg of a triathlon, you spend hours with the weight of your upper body resting in one place: your forearms. Not your hands, not the saddle. Your forearms. They are what hold the aerodynamic position kilometre after kilometre, and they are what go numb, get loaded and start asking you to sit up just when you need to sustain the most watts.

That is why the elbow rest is one of those details that seem minor and decide a long-distance race. A good arm rest doesn't "stand out": it simply disappears. It lets you forget about your arm and concentrate on pedalling. A bad one reminds you of every bump. The CarboXtrem Large-Format Arm Rest was born from exactly that difference.

The problem with EVA foam: comfortable for 15 minutes, crushed after three hours

Most arm rests on the market still use a decades-old solution: an EVA rubber pad. EVA is cheap, light and comfortable… at first. The problem appears over time and under sustained pressure:

• It flattens. The foam gives way evenly and "bottoms out", so after a while you are resting almost on the rigid base.
• It concentrates pressure. Because it deforms as a block, it doesn't spread the load: the point where the ulna rests builds up pressure and tingling appears.
• It doesn't breathe. It traps sweat between your arm and the pad, which is no small thing in hot, long events.
• It "gives out". Over the months it loses its rebound and stays permanently compressed.

On short routes you don't notice. After three, four or five hours in position, you do: a numb forearm is one of the most common complaints among long-distance triathletes.

The alternative: a 3D lattice Pad, the same principle as high-end saddles

The CarboXtrem Large-Format Arm Rest replaces that foam with a 3D Pad, a 3D-printed lattice cushion from the same technology family we use in our high-performance saddles and grips. Instead of a homogeneous block of foam, the pad is a structure of thousands of cells calculated one by one.

That geometry completely changes how the rest behaves:

• It spreads pressure. The cells sink where the bone rests and stay firm around it, distributing the load instead of concentrating it.
• It doesn't bottom out. The lattice works progressively: it cushions without collapsing, even under sustained pressure for hours.
• It breathes. It's an open structure: air circulates and sweat doesn't get trapped against the skin.
• It recovers. The elastomeric material returns to its shape again and again, without "giving out" like foam.

It is the same reason a 3D saddle outperforms a traditional foam one: it isn't about making it "softer", it's about putting the right support at each point.

Why "large format" matters

The other key detail is size. This arm rest is large format: 220 x 100 mm of surface per side. It isn't an aesthetic whim:

• More surface = less pressure per cm². Spreading the same weight over a larger area reduces the pressure peak on the forearm.
• More stability. A wide base holds the elbow better and stops the arm from "wandering", which translates into a steadier position and more precise steering control.
• Room to position yourself. A generous platform lets you adjust your contact point depending on the moment in the race without running out of pad.

The result is an elbow that truly rests in the aero position, instead of an unstable balancing act on a small pad.

Manufacturing: 3D-printed pad and carbon composite structure

The pad is produced by high-performance 3D printing with Carbon DLS technology, the same family of processes we use for our lattices. This lets us tune the density of the lattice to the support area and optimise the pad's behaviour point by point, something impossible with cut foam.

The structure holding the pad is made of carbon fibre composite, aiming for stiffness and lightness so the bracket transmits support without flexing. Like the rest of the CarboXtrem range, it is made in Spain and backed by our lifetime warranty.

Compatibility: universal fit, no brand lock-in

One of the usual obstacles to upgrading your arm rests is the fear that they won't fit your aerobar system. This model is designed with a universal fit: it is compatible with Tririg and similar, Deda and most brands of aerobars on the market. You change the rest without changing the whole cockpit.

Large-Format Arm Rest at a glance

What do you gain in practice?

In terms of what you feel on the bike, a large-format rest with a 3D pad means:

• Less tingling and fewer numb forearms in the final hours of the race.
• Less need to reposition, which keeps you in the aero position for longer.
• More stability and control at the handlebar, especially on rough surfaces.
• Less fatigue in arms and shoulders, energy you save for your legs.

And all of that comes down to the only thing that counts on race day: more sustained watts, for longer, with less suffering.

Frequently asked questions

What sets this arm rest apart from a normal EVA foam one?

It replaces EVA foam with a 3D Pad made from a 3D-printed lattice, the same principle as high-end saddles: it spreads pressure, doesn't bottom out under sustained load, breathes and recovers its shape without giving out.

Is it compatible with my aerobar brand?

Yes. It has a universal fit: compatible with Tririg and similar, Deda and most aerobar brands.

Why is it large format (220 x 100 mm)?

More surface spreads the weight over more area, lowers the pressure peak on the forearm and gives more stability and control in the aero position.

Who is it designed for?

For long-distance triathletes and time triallists looking for maximum comfort and efficiency, reducing fatigue in the arms and shoulders.

Look after the point that holds your position

If you already invest in aerodynamics, in a good position and in training to hold it, don't let a piece of EVA foam force you to abandon it after three hours. The forearm is where long-distance comfort is won —or lost.

Discover the CarboXtrem Large-Format Arm Rest →