A custom carbon gravel bike built for precision and performance

There are gravel bikes — and then there is the Sarto Raso TC Gravel, a custom-built machine made not to follow paths, but to forge them. Handcrafted by a ten-person team in Veneto, Italy, the Raso TC Gravel is not an adaptation of a road frame, nor a carbon copy of trend-driven geometry. It is, at its core, a performance-first, purpose-built bike that brings together experience, experimentation, and endurance.

When visiting Sarto's workshop, it's immediately clear this is not an assembly line but an ecosystem. From carbon cutting to curing, layup to lacquer, each process is handled under one roof. “Every frame is our responsibility,” Tommaso (Sarto Marketing Manager explained). “We don’t outsource. It means every rider gets our best work, not just our best intentions.”

The Raso TC Gravel shares the same Tri-Composite carbon foundation as the road version: a proprietary structure that combines continuous fibre, forged carbon, and carbon infused with copper filaments. Forged Carbon, as Tommaso describes, “uses randomly oriented short fibres to create strength in all directions. It's not just for shaping freedom—it’s a functional choice.” The result is a frame that absorbs trail shock, retains stiffness under acceleration, and performs in unpredictable terrain.

One of the defining features of this Gravel build is its geometry. With clearance for 47mm tyres, it’s tuned for versatility—capable of handling long corrugated stretches, singletrack detours, or bitumen sections with ease. The fork and stays have been shaped specifically to retain agility without compromising stability. As Enrico told us, “The best bikes are never one-dimensional. The frame must respond across different speeds, surfaces, and pressures. That is what we engineered.”

Built for Australian terrain

The decision to exhibit the Raso TC Gravel at SPOKEN wasn’t casual. It reflects Chainsmith’s belief in presenting bikes that not only inspire but make sense for the Australian rider. Our roads and trails are demanding—temperature extremes, coarse bitumen, gravel paths that challenge tyres and patience alike. And yet this frame handles it all with composed control and aesthetic poise.

Every frame is custom built, not just sized. At Chainsmith, we work closely with Sarto using detailed rider assessments to determine geometry, carbon lay-up, and fit. “We work to improve every frame,” said Enrico. “The goal is not perfection in a moment, but bettering the next one—every single time.”

This frame was not built to be flashy. It was built to be flawless. At the same time, it can't escape being falshy!

Carbon Materials and Lay-Up Methodology in the Raso TC Gravel

At the core of every Sarto Raso TC Gravel frame is an advanced Tri-Composite carbon construction — a proprietary blend developed through decades of experimentation in the Sarto workshop in Veneto. This construction includes distinct types of carbon fibre, each selected for its mechanical properties, then layered according to stress, stiffness, and vibration analysis unique to each rider's build.

A Visible Signature: Woven and Forged Carbon in Harmony

The Sarto Raso TC Gravel isn't just distinctive in ride feel — it’s also visually unique, thanks to the interplay between two distinct carbon fibre types strategically used across the frame.

The primary structure of the frame is constructed using high-modulus unidirectional carbon, laid in a traditional woven orientation. This material provides directional stiffness and lightness where it matters most — across the downtube, top tube, and stays. It creates the sleek, familiar carbon texture seen on much of the frame surface.

But what sets the Raso TC apart is the Forged Carbon used at key structural junctions — clearly visible at the head tube, bottom bracket shell, and seat cluster. Forged Carbon is created by compressing chopped carbon fibre strands with resin under heat and pressure. Unlike traditional continuous-fibre layups, Forged Carbon allows for moulded 3D forms and isotropic strength, meaning it performs uniformly across multiple directions.

“Forged Carbon allows us to build frame areas with complex shapes and dynamic stress loads, without overbuilding or adding weight.”
— Tommaso, Sarto

The visual contrast between the smooth woven carbon tubes and the marbled Forged Carbon junctions is not merely aesthetic — it reflects a deep technical rationale. The Forged Carbon offers enhanced load distribution and impact resistance, particularly important for gravel riding where forces are less predictable than on the road.

“We use Forged Carbon to fill specific forms that continuous fibres can’t manage. It adds structural integrity where traditional carbon lay-ups would require more material or compromise shape.”
— Tommaso, Sarto

For the rider, this means a frame that absorbs vibration, resists fatigue, and maintains rigidity in all the right places — even under the harsh and variable conditions found on Australian trails.

Lay-Up Process:

Each frame begins as a custom lay-up plan—never from a pre-existing mold. Rather than using automated pre-preg sheets, Sarto technicians hand-cut and orient every ply based on rider-specific geometry, ride goals, and anticipated terrain. This allows for real-time visual and tactile inspection of fibre alignment and resin saturation, reducing inconsistencies that affect stiffness or weight.

Sarto’s cold-room storage ensures optimal conditions for carbon preservation, and all lamination is performed in-house. The frame is then vacuum-bagged and placed into a custom-calibrated oven to cure. This curing process is critical; it uses a controlled thermal cycle to avoid common issues like resin pooling or microvoids that compromise fatigue life.

“Each curing profile is different. We design the oven parameters depending on the type of fibre and the position within the frame. It’s not one cycle for every frame — it’s many, specific ones.”
— Enrico Sarto

The result is a monocoque chassis where weight is minimised, but strength and durability are tuned per section of the frame. Compliance in the seat stays ensures comfort on washboard gravel, while high lateral stiffness in the bottom bracket and chainstays ensures power transfer on climbs and sprints.

This hands-on process — combined with decades of racing and custom-fit knowledge — enables the Raso TC Gravel to deliver a stable, responsive, and long-lasting ride that’s rare in the world of carbon gravel bikes.

“We are not building for trends. We are building for the rider who wants to feel understood when they ride.” — Tommaso

At Chainsmith we couldnt agree more.

Aesthetic Intent, Functional Distinction

What makes the Raso TC Gravel instantly recognisable isn’t just its custom silhouette or integrated form — it’s the visible contrast between the woven and forged carbon elements, each telling a story of purpose. The shimmering marbled texture at the head tube and bottom bracket offers more than visual interest: it's a direct reflection of the structural demands placed on those zones, and a symbol of the frame’s uncompromising construction.

But the beauty isn’t skin-deep.

The use of Forged Carbon at junctions and unidirectional fibre throughout the tubes translates to a ride quality that is both grounded and responsive. Where traditional gravel bikes might sacrifice reactivity for compliance, the Raso TC Gravel balances both with precision. It filters feedback, not feel — giving the rider confidence on broken terrain, while preserving agility when climbing or cornering at speed.

From its material logic to its refined finishing, the Raso TC Gravel is a bike built to perform with quiet authority — and to leave a lasting impression long after the ride ends.

Critically, none of this is off-the-shelf. The frame geometry is crafted around precise rider data provided by Chainsmith, who translate each client’s biomechanics, riding goals, and terrain preferences into the specifications Sarto uses to build. As Enrico shared, “We create the bike around the customer.” But it begins with the right interpretation. Chainsmith’s role is foundational — not simply fitting, but ensuring that the final frame will ride exactly as intended, from stiffness zones to steering response.

This synergy ensures that each Raso TC Gravel is not just visually distinct, but fundamentally personalised — engineered for the unique rider and their environment.

Let’s take a closer look at the components that complement this exceptional frame.

About the Author – Alison McGregor

Alison McGregor is co-founder of Chainsmith and one of Australia’s foremost authorities on Italian custom bicycles. With over a decade of hands-on experience consulting with Italy’s most revered builders — including direct workshop collaborations with Sarto — she bridges the gap between artisan craftsmanship and rider specificity. Her expertise in the principles of professional bike fitting, component selection, and long-form cycling journalism helps Australian cyclists access truly bespoke builds that perform far beyond mainstream expectations. Every detail in her writing reflects lived experience, deep technical understanding, and a dedication to elevating the culture of custom cycling.