Frequently asked questions about BEAMZ structures, our environmental impact, and the wooden bicycle.
Questions About Wood
What is unique about BEAMZ structures?
BEAMZ make structures out of hardwood poles which grow in nearby woodland. That is the round(ish) young stems of broadleaf trees.
BEAMZ have understood that the grain structure of these poles has been naturally optimised by the growing process of the tree and keeping that structure intact from end to end of the pole offers maximum strength.
Timber, which is square or rectangular section of wood, sawn from a much larger tree trunk, often does not have continuous grain from end to end, and the natural reinforcement effect represented by the bulge around knots is nullified.
What is hardwood?
Hardwood is the wood from a broadleaf tree (oak, ash, elm, birch, beech, hazel etc.).
By contrast softwoods come from needle bearing trees like pine and spruce.
As you might expect, the wood from UK hardwood species is generally harder than softwood, although world-wide there are some notable exceptions, with Balsa, one of the softest woods coming from a broadleaf tree and therefore being technically classified as a hardwood.
Hardwood is generally denser and has greater strength across the grain compared to softwood.
This leads to a higher Modulus of Rupture (MOR) for hardwoods.
Wood has to be an extraordinary structural material.
The wood in a tree is a dead material unlike bone, so if a crack were to occur there would be no biological mechanisms to repair them. That is why wood has evolved it's strength and longevity.
Wood often demonstrates its ability to support the load of the tree and the fluctuating loads caused by the weather for decades or sometimes centuries.
Why do you make your bicycles from wood?
· Excellent strength to weight characteristics comparable to typical bicycle materials.
· Improved ride quality through the ability of wood to absorb shocks.
· Natural beauty. Every bike is guaranteed to be unique!
· Robust finish resistant to dents and scratches.
· A sustainable material with low energy requirements for both extraction and processing
· Finally, on a personal note, we hope to change perceptions, and encourage people to think about using wood as a raw material for new applications.
Isn’t metal much stronger than wood?
When compared on a weight for weight basis in practical structural application wood is comparable or better than metal.
A wooden component designed to carry a load will have the same strength as a metal component designed to carry the same load.
It is true that for identical sections of wood and metal, the metal will be stronger, but it will also be four to ten times heavier.
Comparing sections of equal weight in well-designed structures allows wood to equal or exceed the performance of the metal.
Is using wood to make bikes sustainable?
Yes, provided the woodland is sustainably managed. Developing a use for the wood creates economic support for existing woodland and an incentive to plant additional sustainably managed woodland.
This is a huge benefit to the environment.
Sustainable management means that the wood is only harvested from the forest at the rate that it can be grown and that the harvesting and the subsequent management of the woodland will allow regrowth and maintain and enhance the ecosystem of the woodland.
How do wooden bikes help with wildlife diversity?
The best way to grow poles for BEAMZ is through coppice management of woodland.
Coppice management is acknowledged to be excellent for wildlife diversity.
This kind of management was commonplace in the UK for over a thousand years, declining in the 1930s to the detriment of many indigenous species.
Is it like a bamboo bike?
We sometimes hear this comment. Many cyclists are aware that bike frames have been made from bamboo.
BEAMZ bikes are made from hardwood trees which grow locally to us.
We love and support bamboo bike making, but feel that it is most appropriate in the many parts of the world where bamboo grows.
It might be possible to grow bamboo in the UK, but as a non-native species it wouldn’t provide support for the local wildlife.
A birch tree for example supports over 300 species of invertebrate, whereas a sweet chestnut, which was introduced comparatively recently in ecosystem terms, by the Romans, only supports five.
An advantage of bamboo is that it comes pre-hollowed by nature whereas BEAMZ have to hollow the larger section poles. Of course that does give us complete control over the wall thickness, which we can vary along the pole.
If wood is so good, why did we stop using it?
In a historical repeating pattern, coppice wood was superseded by timber once mechanical saw mills became available.
Tropical hardwoods were found in what, at the time seemed to be limitless virgin forests.
With no forestry costs for growing the trees and low cost local (slave) labour to fell them, they displaced indigenous timber.
The coking process allowed a dramatic scaling up of iron production and the Bessemer process allowed steel to become ubiquitous.
By the end of WW2 aluminium had, apart from a few notable exceptions (DeHaviland, Hughs), displaced wood in the aviation market.
In each case wood was the legacy material and the supporters of the new material would run a less than impartial campaign to show its advantages.
At the same time material science students were attracted to study and research the new wonder materials allowing the knowledge-base surrounding the engineering applications of wood to atrophy.
In 1998, I was introduced to the work of Professor Mike Ashby, in his excellent book, Material Selection in Mechanical Design [PDF]. The book contains a number of worked examples, one of which is bicycle forks.
The conclusion of the study was that wood, in solid form was nearly as good as steel or aluminium, when their performance had been improved by shaping the material into tubular structures.
It was clear from this that a wooden structure with hollow members could exceed the performance of a metal structure.
Another insightful book is Wings of Wood, Wings of Metal by Eric Schatzberg,
Is there metal inside the wood?
BEAMZ have full confidence in the strength of wood, and we try to use it wherever possible, including forks, seat-posts, mudguards and handlebars.
It is and always has been a remarkable strong lightweight material which does not require metal or composite reinforcement. BEAMZ do use a thin bonded in steel lining for the bottom bracket threads, to interface with industry standard bottom brackets.
The drop-outs which support the wheels are cast from aluminium, recycled from certain brands of alloy car wheels.
This use of aluminium has a far lower energy cost compared to refining virgin aluminium.
Questions About Environmental Benefits
What is embodied energy and why is it important?
It is the energy embodied in all the products we buy. It includes energy to make the materials, which in the case of metals is very high, then forming the materials into the product and all the transport in the process. In a world where 85% of our energy comes from fossil fuels it is vital that we reduce our energy requirement.
It is vitally important because it is the biggest contribution to the excessive use of energy for which we are each responsible. It is greater than road transport, heating or air travel. It is not represented accuratly in the UK Government statistics because the manufacturing often takes place overseas, often in places where high-carbon energy sources such as coal-fired powerstations are still common.
Humanity has come to rely on materials and energy sources which are dug out of the ground, often in poor nations with weak governance in the face of the the huge financial incentives. The mining, oil and gas industries are often responsible for infringing the rights of indigenous people and damaging their environment and livelyhood.
Refining metals is highly energy intensive and produces a great deal of carbon dioxide.
It is for this reason that although the energy we use for road transport, heating our homes and workplaces and air transport are large, the biggest segment of energy for which we are each responsible is the energy embodied in the goods we buy.
What is the embodied energy of BEAMZ structures?
As the tree grows from a seed, the only materials required or within reach to make the wood are air, water and a tiny amount (about 1%) of other minerals from the soil.
The energy required to turn these elements into wood is collected from the sun by the leaves, in a process known as photosynthesis.
BEAMZ use the wood in its natural form thereby minimising further energy requirements.
To creating each kilogram of wood, the tree takes about 1.7kg of carbon dioxide, the gas responsible for global warming, out of the atmosphere.
Of this 0.5kg of carbon is locked up in the wood while 1.2 kg of oxygen is released back into the atmosphere.
Greenwood from a living tree is about 50% water by weight.
When wood is harvested it dries out, causing three very useful consequences.
The weight of the wood is approximately halved, while the strength is approximately doubled.
The third benefit is that the organisms which cause wood to rot, cannot function below a 22% moisture level, so dry wood does not rot. Wood is usually made into timber or an engineered wood product.
Engineering wood products, plywood, MDF, hardboard, oriented strand board, chipboard etc. are made by cutting the wood into plies, strands or particles, then reassembling it into sheets.
This processing requires energy and chemical input. BEAMZ believe that using the wood in its natural form is best from a material and environmental perspective.
The wood can be cut and removed from the forest by hand with little further processing. Larger diameter poles, can be hollowed, greatly improving the strength to weight ratio of the pole, and allows it to dry in a short timescale without cracking.
Different species of wood have characteristic textures under the bark which offer a very attractive and hard-wearing finish.
Timber structures can warp because the planks are cut from a tree-trunk where amounts by which the radial and tangential dimensions change with temperature and humidity differ by as much as 2 :1. BEAMZ poles are symmetrical about the axis so this problem is eliminated.
What is Coppice management?
When broadleaf trees are cut down, the remaining stump of most species sprouts a large number of shoots. These shoots grow into poles.
After the time required for the poles to grow to the required diameter, the poles can be harvested and the process begins again. The stool of the tree can live for over 1000 years when used in this way.
In practice the woodland is divided into a number of areas, usually seven to twelve, called coups. Each year, one coup is cut to provide poles.
The periodic cutting allows sunlight to reach the ground encouraging woodland plants to grow. These plants are a vital food source for invertebrates (bugs).
The following year another coup is harvested so that there is always an area of open woodland with plants.
Invertebrates, depending on how they move about, can relocate to a new environment as long as it is not too far away, so coppice working provides a continuous environment for these creatures.
In a fully developed woodland, most of the wildlife is within 50m of the edge with the dark centre being comparatively barren. This is because nearly all life derives its power from the sun.
Plants do this directly by photosynthesis while animals get the energy by eating the plant matter, or nectar, an energy rich food which flowering plants provide to attract pollinators.
The cutting of coppice coups creates in effect, a moving woodland edge allowing rich diversity to develop.
Why do you prefer to use wood that has been coppiced?
· Creates straight poles with fewer side branches (and hence fewer knots) as the new growth rushes upwards towards the light.
· Increases wildlife diversity by up to 400% compared to other forestry practices.
· Increases the life of the tree. A coppiced lime in Westonbirt Arboretum is over 2000 years old.
· Supports jobs in the countryside.
· Easier to fell and extract the trees as they are smaller.
Why are invertebrates important?
Invertebrates are creatures without a backbone. The group comprises insects (six legs and often wings), arthropods (many legs), worms and molluscs.
Some are beautiful creatures like butterflies while others, to many people are frankly quite hideous.
They are of vital importance because every species which makes up an ecosystem plays a role as a predator, a food source, or by breaking down plant matter, animal matter or soil to make nutrients available to other organisms.
Our understanding of these relationships is by no means complete, so losing component parts before we fully understand their function carries a very high risk.
Of course, wildlife diversity also concerns larger creatures such as birds, mammals, amphibians and reptiles. These creatures are further up the food-chain, so often their population decline is a result of problems at the bottom of the chain.
Questions About BEAMZ
Do you have a vision?
At BEAMZ, our vision is: “To create beautiful, high performance, bespoke bicycles from wood in the most sustainable, environmentally friendly and inclusive way.”
What is a social enterprise? What is an Impact?
BEAMZ is a not-for-profit social enterprise.
It is similar to a company in as much as it sustains itself financially by selling products (bikes etc.) but whereas the purpose of a company is to create a financial return or profit for the owners or shareholders, the purpose of a social enterprise is to create social returns or impacts.
The objective of BEAMZ is to synergistically create three vital impacts.
Reducing climate change, supporting wildlife diversity and supporting wellbeing.
We believe that creating these impacts will make the people who run, work for, support and ride BEAMZ very happy.
Because the impacts occur as a result of making bicycles, financial surpluses will be used to grow the operation and thereby grow our impact, geographically and in new product areas.
How does BEAMZ create wellbeing?
BEAMZ will create work and voluntary activities involving skilled manual work, working with wood and working in woodlands.
These have all been shown to be very helpful in supporting and repairing the poor mental health which is reaching epidemic proportions today.
Many conventional employment opportunities either ignore or exacerbate the issues of climate change and wildlife diversity, casting a long shadow over our sense of wellbeing.
Why are the 'Three Impacts' so important?
Each action or decision must be considered in the light of the three objectives and no objective, or aspect of the objective will overwhelm the others.