One Bamboo Bike, Two Personalities: Guillaume at the Concours de Machines

Guillaume Denneulin builds bamboo bikes at BambouBécane, his workshop in Pinsaguel, just south of Toulouse. Since 2024 it has also been home to our Toulouse partner workshop. In September he took a bamboo bike with two personalities to the Concours de Machines 2026: a calm road bike that turns into a bikepacking bike in under 10 minutes.

What is the Concours de Machines?

It's a French competition for handmade bikes, with roots that go back more than a century. The Association des Artisans du Cycle revived it in 2016. Each edition gives builders a brief, then the bikes are ridden and judged.

The 2026 edition ran from 25 to 27 September in Saint-Michel-de-Maurienne, in the French Alps. Its theme was "Multipersonnalité et Sobriété", which means roughly "many personalities, and doing more with less". Here's what the brief asked for:

• One bike, several jobs: a light road bike that converts into a bikepacking bike for rough tracks.
• Ready for a night out: lights, a repair kit and luggage for a bivouac.
• Inclusion: a section written with the French disability sports federation, the Fédération Française Handisport. Riders had to be able to handle the luggage with one hand.
• A real test: a route over the Col du Galibier, with the conversion done along the way.

Guillaume was one of 7 builders in the main competition.

Calm on the road, a storm off it

The organisers summed up his bike in one line: "Beneath the Zen print, a storm rages." In road mode it's the calm side. The lines are clean, and a blue pattern inspired by Japanese woodblock prints wraps the frame joints and carries on to the wheels.

In bikepacking mode it turns rebellious. The bags carry an illustration of a disabled, activist panda, made with the illustrator Colère et Bagarre. It takes the "many personalities" theme right through to how the bike looks.

Black bamboo, flax and carbon

The frame uses 2 kinds of bamboo. The seat stays are Phyllostachys nigra, often called black bamboo. The other tubes are Phyllostachys viridiglaucescens. The joints are reinforced with a mix of flax and carbon fibre, set in a partly bio-based resin. Guillaume chose them to balance lightness, strength, comfort and environmental impact.

9 minutes 40 seconds to change

Changing personality is mostly a wheel swap: 28 mm tyres for the road, knobbly tyres for the trails. Then the bamboo racks and the bags go on. At the competition the change took 9 minutes 40 seconds, and the technical commission weighed the bike at 9 kg.

The racks are bamboo too.

Bags from old sails and tents

Fabrice Delahaye designed and made the bags, and he also rode the bike in the competition. He made them mostly from reused fabric, such as boat sails and tent canvas. They close with Fidlock magnetic fasteners, so you can handle them with one hand. That met the inclusion part of the brief.

Fabrice plans to publish the patterns as open source, so anyone can make, adapt or repair the bags.

Bravo, Guillaume and Fabrice

The podium went to PechTregon Cycles, La Fourche Cycles and Arpège Cycles. Congratulations to them and to every builder who took part. Guillaume and Fabrice's machine shows what bamboo can do when a builder thinks hard about materials, reuse and access, and still makes something beautiful.

Build a bamboo bike with Guillaume

Guillaume teaches bamboo frame building at BambouBécane, 15 minutes from Toulouse. Over 3 to 5 days you design and build a complete bamboo bike with flax-and-epoxy joints. The course is taught in French. See the Toulouse workshop, or meet Guillaume.

Not near Toulouse? Join a workshop in London, or build at home with one of our frame kits.

Photos: Zag Pictures (@zag_pictures) for the Association des Artisans du Cycle. Sources: the association's Instagram post about the bike, and concoursdemachines.com for the event and results.