Why a wood and carbon bike?
As designers and engineers we are fascinated by materials and our pallete of material tools here at Coh&Co Copenhagen is quite broad. We began as carbonfiber/ composite specialists in the marine industry and have since gained considerable experience in the design and manufacturing of different projects, utilizing everything from aluminium to stone.
Given this background it is therefore not surprising that we at Coh&Co often get asked why we have chosen wood for our WOOCA bikes when we are so clearly open to other materials. Many assume that it is for aesthetic reasons, and although we are flattered by the complement, we believe that the beauty here is far more than skin deep. The beauty is in the ride.
Wood as a structural material
Wood is one of nature’s most fantastic engineering materials. It’s tough and resilient and it has an incredible ability to withstand cyclic fatigue that is very difficult to match. It also has some really great harmonic characteristics that lend themselves to bicycle design. Wood cannot be discounted as an engineering material – lets face it, trees tower up to 100 meters into the air and do so borne by foot prints which are proportionally smaller than that of the highest skyscrapers. Trees last for centuries and in extreme cases millennia (some Sequoias have been shown to live for 3,500 years and reach over 100 meters into the air), while regularly surviving storms, earthquakes, rot and even in some cases, forest fires – this is a formidable structural material. Wood also has a harmonic range that is very compatible with the human machine. There is something warm and natural about wood that is almost mystical, but it is possible to substantiate it.
The human machine harmonises with wood
We humans are living organisms and we respond to the environment around us. One of the things we respond to is vibration. Holding a vibrating tool or instrument (even lightly) will affect blood flow to the hands (or whatever region is in contact with the vibration) thus reducing blood flow. This means that less oxygen reaches the cells and ultimately muscle performance and power become exhausted. As it happens, “road noise” – or vibrations transmitted from the road surface through the bicycle to the riders hands, feet and groin – provokes a condition where the body systematically reduces blood supply to the areas affected by vibration and we lose power… In extreme cases the body can reduce blood flow by as much as 20 or 30%. One of wood’s great strengths as a frame building material, is that it is incredibly good at absorbing these “road-noise” frequencies that are in the irritating part of the spectrum, without giving up on strength or flexing. This means that we can produce a frame with an unparalleled ride experience utilizing wood to absorb the unpleasant harmonic disturbances from the road – without the need for all the fancy gadgets and design gymnastics required when designing with other frame building materials.
A wood and carbon hybrid frame = stiffness
However, one of the characteristics that makes trees so incredible is the resilient nature of wood and although this may make trees really tough and very strong, it is not usually associated with extreme stiffness. Stiffness is part of what we need for power transfer. This is why we have chosen to combine wood with carbon. As is the case in any successful composite structure the choice and marriage of the right materials can augment the performance of the individual contributors.