The T-72B Space-Frame Bicycle: A Homage to Ettore Bugatti’s 1943 Design.

Few engineering visions capture the imagination quite like Ettore Bugatti turning his mind to two wheels. While Bugatti is synonymous with legendary Grand Prix cars like the Type 35 and breathtaking automotive engineering, his obsession with lightweight structural design extended far beyond four wheels.

This is the story of a forgotten wartime blueprint, a handful of master-built homage frames, a French museum discovery, and a thirty-year personal journey to bring an extraordinary multi-tube design to life.

The 1943 Drawing

My connection to this story began roughly thirty years ago. A customer of mine—a respected Bugatti restorer for whom I was restoring vintage bicycles—handed me a printed copy of an original technical drawing.

Dated 1943, amidst the turmoil of World War II in occupied Paris, the drawing bears the signature of Ettore Bugatti and carries the original factory designation 72B. Unlike standard diamond frames of the era, the blueprint depicts an intricate space-frame architecture—a web of slender main tubes engineered for maximum rigidity and minimal weight, reflecting the same structural philosophy Bugatti brought to his aircraft and racing chassis.

I have held onto that paper copy for three decades, studying its lines and proportions, waiting for the right moment to translate those drawn dimensions into steel.

The Replicas & Modern Commissions

Over the decades, the drawing's physical history in the modern era has been preserved through a tiny handful of craftsman-built frames, commissioned or constructed by dedicated Bugatti enthusiasts across the globe:

• The First Art Stump Frame: Built by American master builder Art Stump and owned by the very Bugatti restorer who entrusted me with the 72B blueprint copy all those years ago.

• The Second Art Stump Frame: Preserved in the collection of renowned historic car restoration specialists Crosthwaite & Gardiner—a workshop famous worldwide for reproducing lost Grand Prix Bugattis and pre-war racing machinery.

• The Charles Dean Commission: Commissioned by the late Charles Dean—a revered figure in vintage motor racing and a lifelong Bugatti owner—who engaged a master Italian frame builder to construct a frame to the 1943 specifications.

• The Rupert Marks Build: Constructed by dedicated Bugatti owner Rupert Marks, adding another authentic collector-built chapter to the physical legacy of Ettore's design.

• The European Ornate Homage: A replica located on the Continent—a striking, highly ornate interpretation heavily adorned with classic Bugatti logos, demonstrating how differently collectors have sought to celebrate Ettore's aesthetic legacy.

Whether the original commission to Art Stump came directly via Dick Crosthwaite remains part of the surrounding lore, but alongside the Charles Dean frame, the Rupert Marks build, and the European homage, these rare creations proved that Bugatti’s 1943 72B design was not merely theoretical—it was a functional masterpiece waiting for skilled hands.

The Provence Discovery: A Physical Blueprint in Steel

Beyond the drawing and these modern craftsman homage frames, another remarkable chapter unfolded in the physical history of this design.

For years, an actual frame built to the Bugatti pattern resided in the collection of the Musée Automobile de Provence in southern France. To make it recognisable as a complete bicycle, it had been assembled using period donor parts—a Stronglight chain-set, along with a set of wheels and handlebars that served to give the bare space frame a complete silhouette.

Accounts from the museum's history link this frame, along with other rare period cycles, back to items preserved by the Bugatti family estate following Ettore Bugatti’s death in August 1947.

In 2022, classic vehicle specialist Christophe of Galerie des Damiers acquired three extraordinary machines from the Provence collection: the Bugatti space-frame prototype, an octagonal-tubed aluminium Caminargent, and an early fixed-gear circus bicycle with a block-link (inch-pitch) chain and rigid straight forks.

According to factory lore, that circus bicycle wasn't just a display piece—it was ridden around the Molsheim factory floor by Ettore himself for fun, serving as a playful daily runabout among the Grand Prix cars and railcars.

In March 2023, I traveled to visit Christophe in France to inspect the collection firsthand. Holding a tape measure to that frame was the ultimate moment of truth: the physical dimensions and frame geometry matched my 1943 72B drawing exactly.

A Craftsman’s Perspective: Prototype or Thought Experiment?

Having spent decades working in the bicycle industry—including time with Pashley Cycles in the UK—I look at the Provence frame with a builder's eye. What I was holding in France bore all the hallmarks of an original working prototype built to evaluate the paper design.

Designers like Ettore Bugatti, for all their visionary brilliance on paper, often needed physical objects to hold, test, and study. Ettore’s fascination with lightweight, two-wheeled transport wasn't a sudden wartime whim—it was baked into his engineering DNA. At just seventeen years old, he began his career as an apprentice at the Italian bicycle and tricycle manufacturer Prinetti & Stucchi. His early experiments with motorised tricycles and early space-frame geometry sketches laid a foundation of light-gauge structural thinking that he would return to repeatedly throughout his life.

During his wartime stay in Paris—where he was known to have sketched various lightweight transport ideas and bicycle components—it is entirely plausible that Bugatti commissioned a local frame builder to translate his 72B blueprint into steel.

A master frame builder looking at Bugatti's initial drawings would immediately spot structural flex issues. This likely explains a key detail found on the Provence frame and the subsequent replica builds: the delicate diagonal cross-bracing. These small tie-tubes were almost certainly a craftsman’s practical intervention to prevent flex and reinforce the long main tubes under real-world loads.

Studying the State of the Art & The Unfinished Vision

The presence of the Caminargent alongside the space-frame prototype in the estate collection offers a fascinating glimpse into Ettore’s process.

With its octagonal aluminium tubing and cast-alloy lugged construction, the Caminargent was one of the most avant-garde production bicycles of the 1930s. Ettore undoubtedly acquired it to study its alternative joining methods and cast structural components.

While the Provence prototype was hurriedly assembled using standard pressed steel dropouts—typical of a quick, working proof-of-concept—it is highly probable that Ettore intended a final production version to feature custom cast dropouts modelled directly on the elegant Caminargent lugs. Because production was never realised in wartime Paris, those bespoke castings were never fitted to the original test frame set.

Was his design born out of wartime necessity, as severe fuel shortages forced a pivot toward simple personal transport? Or was it purely an intellectual exercise for an idle engineering genius?

Adding to the mystery is another project Ettore created during this exact wartime period in Paris: his miniature Type 72 cycle-engine experiments. Designed as an ultra-compact clip-on motor for bicycles, the Type 72 was a marvel of miniaturised Bugatti engineering—a single-cylinder engine of roughly 10.5cc to 14cc featuring twin overhead camshafts, a tiny multi-plate clutch, and even a miniature Roots-type supercharger.

Whether a Type 72 micro-engine was ever destined to be mounted inside this intricate 72B space frame remains one of those wonderful, unanswered Bugatti enigmas. But the shared designation, the timing, and the sheer audacity of both concepts point to a mind actively reimagining lightweight personal mobility when the rest of the world stood still.

From Paper to Precision: The Modern Reconstruction

The journey from paper to metal took a decisive leap forward during my time hosting a vintage bicycle workshop at the Goodwood Revival. It was there that I was introduced to Paul Cameron, a talented CAD designer who shared a passion for classic engineering.

Combining the historical 1943 72B blueprint with the precise physical measurements I gathered from the Provence frame in France, Paul set to work digitising the entire geometry.

Because an intricate multi-tube space frame cannot be built using standard frame jigs, Paul did not just model the bicycle itself—he engineered full digital schematics for a custom frame-building assembly fixture. This bespoke jig securely holds every slender main tube, seat stay, and diagonal cross-brace in perfect alignment, ensuring absolute accuracy.

With the CAD data finalised and the assembly jig designed, the dream is finally ready for the torch under the 72B Space-Frame designation.

Technical Fabrication & Engineering

"A space-frame is not merely assembled; it is balanced under heat. When joining micro-diameter tubes and contrasting metals, careful flame control and solder flow make all the difference."

Building a standard bicycle frame involves joining eight large tubes. The T-72B Space-Frame is completely different—it is a complex, 3D web of over thirty individual micro-tubes, cross-braces, and custom-machined joints, faithfully recreated using the exact measurements taken from the Provence estate prototype.

Bringing Ettore Bugatti’s 1943 Paris concept to life requires three key craftsmanship steps:

1. Tube Selection & Ettore’s Mixed-Metals Philosophy

A traditional frame relies on heavy, large-diameter tubing to stay stiff. The 72B achieves its strength through a web of triangles—spreading loads across multiple slender tubes to keep the total bare chassis mass exceptionally low.

Ettore Bugatti was famous for mixing contrasting metals whenever function and aesthetics collided. The 72B reflects that exact philosophy:

• Main Members (10mm OD x 0.8mm Wall Chromoly): Precision cold-drawn chromoly micro-tubing forms the primary structural paths. Utilising a thin 0.8mm wall thickness optimises structural rigidity while maximising weight savings across the multi-tube bundle.

• Cross-Bracing (6mm OD x 1mm Wall Brass): True to Ettore’s love for mixed-metal construction, the delicate internal ties are made from 6mm brass tubing. These brass ties stabilise the long 10mm steel runs against flexing while adding a striking visual contrast against the steel.

• Cast Bronze / Hard Brass Dropouts: Completing Ettore’s unfulfilled production intent, both the front and rear dropouts are custom cast in high-tensile bronze or hard brass, styled in the distinct architectural design of the period Caminargent fittings he so admired.

• Machining: Bottom bracket shells and head tube sleeves are custom-turned on a lathe.

2. CAD Precision & Custom Build Fixture

When 10mm steel and 6mm brass tubes meet at tight angles, even a 0.1mm gap will ruin a joint.

• Every tube angle is modelled in CAD for exact laser-notched fitment.

• Assembly takes place in a custom-engineered fixture (jig) built specifically for this multi-tube layout, holding every individual 10mm steel tube and 6mm brass tie in perfect alignment.

3. Low-Heat 55% Silver Soldering

Traditional bronze welding requires intense heat (above 850°C), which would warp thin 0.8mm wall steel and damage the delicate 6mm brass ties. Instead, we use 55% High-Purity Silver Solder:

• Protects the Metals: Silver melts at a much lower temperature (~630°C), joining steel to brass and cast bronze dropouts seamlessly without overheating or distorting thin-walled material.

• Deep Capillary Flow: As the torch warms the joint, molten silver acts like a liquid magnet, drawing itself deep into the microscopic gap between the steel, brass, and cast components to form a smooth, incredibly strong bond.

• Absorbs Road Vibration: Silver joints remain slightly flexible compared to harsh bronze welds, allowing the multi-material frame to absorb road shocks without cracking over time.

Craftsman Note: Left unpainted and un-filled, a completed T-72B frame set showcases the rich golden hue of the 6mm brass ties and cast bronze dropouts against the raw steel main tubes, framed by clean silver rings at every joint—an honest, unvarnished testament to precision layout, torch control, and Ettore Bugatti’s signature aesthetic.

Owning a T-72B Space-Frame Bicycle.

Ettore Bugatti famously believed that a functional object should first and foremost be a work of art. The T-72B Space-Frame represents the absolute pinnacle of that philosophy—a rare intersection where pre-war Grand Prix pedigree meets two-wheeled engineering.

These frames are not mass-produced, nor are they altered for modern proportion. To maintain total historical fidelity, every frame in this limited series is built strictly to one authentic specification—faithfully reproducing the exact dimensions and frame geometry drawn by Ettore Bugatti in 1943.

Production Timeline & Collector Inquiries

Assembly of the initial hand-built frames is scheduled to commence over Autumn and Winter 2026/2027.

Due to the extreme complexity of silver-soldering over thirty individual steel and brass members into a bespoke fixture, production will be strictly capped to a small, serialised batch:

• Archival Geometry: Built exclusively in the single, original frame size as defined on the 1943 72B blueprint and verified on the Provence prototype.

• Individually Serialised: Every frame will bear an individually engraved, registered serial number denoting its precise build sequence in this limited edition run.

• Certificate of Authenticity & Provenance: Accompanied by a signed leather-bound portfolio documenting the fabrication process, tube geometry, and the full historical lineage tracing back to the 1943 original 72B blueprint and the Provence prototype.

Expressions of Interest:

Pricing for the initial limited production run is currently being finalised. Anyone interested in acquiring a T-72B frame set or learning more about the upcoming build process is invited to contact us directly to register their interest.

Legal Disclaimer & Historical Notice: This project is an independent artisan frame-building enterprise project and is not affiliated, associated, authorised, endorsed by, or in any way officially connected with Bugatti Rimac, Bugatti Automobiles S.A.S., or any of their subsidiaries or affiliates. References to Ettore Bugatti, historic vehicle models, and 1943 archival drawings are used strictly for descriptive and historical contextual purposes to identify the origin and inspiration of the frame geometry.