In early February 2012 Humans Invent visited the ‘Flying Scotsman’ Graeme Obree at his home in Saltcoats, Scotland. The 46-year old maverick was embarking on hand-building a bicycle in his kitchen capable of breaking the human powered land speed record this September in America. A man with a history of being marginalised for his innovation, Obree had returned to once again challenge conventional engineering and bike design by using his unique investigative mind to create a blueprint for a hand-built bicycle that could reach speeds up to 100 mph.
Humans Invent returned to Obree’s flat in May to see what progress had been made and how his restless inquisitiveness and curious nature had impacted the design and build process. Still working from his kitchen table, with bags of nuts and bolts, dust filling up his flat and still with a solitary jar of coffee as his fellow engineer, Obree has finished the main frame of the bike and is a matter of weeks away from officially unveiling the design of the bike.
Still resisting any labs or research assistance, we mined the unique mind of Obree once again, on this occasion with the aim of finding out the fundamental principles of the bicycle’s design and the methodology behind Obree’s unique train of thought.
On reflection, entering the psyche of a man uniquely dedicated to his craft with a burning desire to succeed, Obree shares the three key characteristics of an inventor that Einstein speaks of, “curiosity, obsession and dogged endurance.”
Despite this obsessive behavior, Obree is looking forward to finishing the build, mainly so he can get his flat back, “I am nearly there. I think it’s time I got it finished. I need my flat back; you cannot go on forever living like this.” Although we’re not sure. If there is one man who could live in a workshop cum home forever, it’s Obree. He does look in his natural habitat. After all, his philosophy is centered around a holistic approach to design and it certainly seems to be working.
Time to step inside the mindset of a true pioneer once again and investigate the origin of his core design principles. This is the Obree way…
Graeme, a pleasure to see you again, good to see the bike is looking fantastic. Can you talk us through the inspiration for the design of the bicycle?
Well, the design came about because I thought to myself, right ok, this is not about human rules anymore. This is about the laws of physics and that is the only constraining factor. I mean there are rules. The basic rules are you have a flat road, no assistance, no downhill run, no wind assistance – so basically a human being has to use its energy in real time to fly across a road through the atmosphere.
A sky diver, head first, traveling through the atmosphere is obviously the most aerodynamically efficient position for a human being
So I thought to myself, what are my limiting factors or limitations of possibilities? What is the edge of the cage of possibilities? So, thinking about the laws of physics the first rule is aerodynamic resistance. That is the overwhelmingly 90% of the energy you will use to do this is against aerodynamic resistance. I thought ok, therefore how do I minimise aerodynamic resistance?
Ok, What is the given, the unchangeable, the immutable minimum that you have to endure as a resistance? And that is the human body. The only part of this that isn’t changeable or adaptable is the human body. Or the part that you cannot innovate. So if that is your limitation you are building everything around it, then, what you have to think is, what is the maximum possibility for the human body aerodynamically?
So I immediately thought of a sky diver, head first, traveling through the atmosphere is obviously the most aerodynamically efficient position for a human being. Your arms are tucked in and possibly even your shoulders tucked in as well, which I have actually done on my bike, to the best I can without restricting my breathing. But that comes later. Head first, with your legs absolutely straight and your feet together – that is the most aerodynamic position for a human being. But, then comes the problem. You have to deviate from perfection in order to obtain energy. So having looked at the possibilities of using your arms and other muscle sources, really the legs, as they contain the largest muscles in the body, they have to move in some way to deviate from perfection and extract the energy in your body.
What was your thought process when you were sketching the design?
The thought process was, what is the absolute minimum amount you are going to give away from perfection in order to achieve the most amount of energy? Now, when I say the most amount energy, I am asking what are the limiting factors to how much energy you can get out? Well the limiting factor in the human body in this situation is probably the heart and lungs function, so, the main question is how much oxygen can you assimilate and turn into energy?
This is about the laws of physics and that is the only constraining factor
Once the muscles are moving enough, you won’t be able to get anymore energy out because you are limited by the heart and lung function anyway. Looking at it scientifically the least amount of deviation is that nothing can go between the ankles, nothing equipment wise at all because it immediately widens the human body. That was a golden rule. And you don’t want any equipment outside the feet because it is going to cause further resistance aerodynamically.
There is a choice. You can either go head first or head behind. Now if you actually analyse it in terms of the width of the shoulders, it is the widest part of the body. If you look at this scientifically the most aerodynamic shape for anything is a teardrop shape, and that is a known fact. So you want to start from wide to not-so-wide, which is the hips, that is the limiting factor. Unless you are going to get surgery you cannot limit the size of your hips, they are what they are, which is slightly narrower than your shoulders.
So if you put your feet together if they are moving and they are just touching each other they are marginally narrower than your hips. So what you have is shoulders, hips and feet – which tails down into a tear drop shape. Obviously head first is the way to go. The reason the human body is so efficient with this design is that it has minimum frontal area – so any deviation from this is increasing the frontal area – the aim being as little as possible with maximum muscle movement. The other factor is the amount of skin, when this is covered over – the amount of skin surface is still an important and a decisive factor. In terms of the air rushing past it, it does grip it. If you go head first in a tear drop shape down to the feet, that means you don’t have as much space to make it aerodynamic. So the vehicle is uniquely shorter, so there is less skin.
Can you talk us through the hip and shoulder support? What was the origin of that part of the design?
Interestingly, when I built the hip and shoulder support for the exact design, I actually got my son Jamie to squish a cabinet against my shoulders to see how narrow my shoulders could get without restricting my breathing. The absolute width of this vehicle is dictated by how narrow I can get my shoulders. I actually managed to squeeze them in to almost the same width as my hips. I think there is only about a 1cm difference. So it is like 36 cm up top, 35 cm at my hips, 25 cm at my feet – this is a very short vehicle. There is a lot of force going through such a small vehicle so it has to be sturdy – just in case you get a bump.
For example, look at the fork blade, it could hold a 20 stone man. It is cold rolled, butted and incredibly strong British tubing. The good thing is you can heat it and bend it like a blacksmith. I’ve done that and it was worth the effort. When you do the mathematics if you can save 1 cm off the side of a vehicle it is worth an extra 2 miles an hour. For me, each mm is worth fighting for! That is worth more than anything else. You need to have an obsessive nature over the frontal area.
The saucepan was used for the curvature for where my shoulders are. I needed to use a lightweight metal and so I went for stainless steel. If I used aluminum you would have to bolt that on as you cannot weld it to steel. And you would have to use lots of glass fibre if you went with that instead, so I thought an old saucepan would work perfectly. It already had a curve in it – sacrifice a saucepan and the whole job took about two hours.
My starting point is first principles. I think other people have thought like this but once you deviate from what the norm is it becomes increasingly difficult to build anything. I mean looking at all the components I have used to build this, I have used bike components where I can, and the tyre frame is all new, but what you are struggling with is it being cutting edge. While if you copy what other people have done, which is a recumbent bike you can buy all the parts you need. As long as you know what head angles and frame angles you need, you can buy all those components to build your own design of a recumbent. But what I am doing is completely new, it is cutting edge. A lot of people have seen the success of the world record on a recumbent bike and they just want to improve it, for example making it lighter, narrower, or more efficient.
So, what you are saying is there is a choice for every designer?
There is a choice. Either you make a compromise, or you say, ‘right this bike is being built for me and me only, and is built for my body – my hips and my shoulders’. The reason being, as soon as you make something universal then you are giving away percentages of perfection – which is giving away an advantage. Mechanically, anything that has been joined together in a kitchen has the potential to go wrong. There was an inordinate amount of time spent working out where they had to go exactly.
There is a choice. Either you make a compromise, or you say, ‘right this bike is being built for me and me only’
The good thing is I actually have the blueprint right here, at my fingertips. It is me. I have the advantage that other engineers don’t have with my project. Normally what happens is the engineer goes and builds the best bike he can and then says, ‘right who can we go and get as an engine?’ They are forced to have a bike that will fit riders of a certain size, but I have the advantage of saying, that bit for example has to be the same size as my hips, so let’s measure it. So I can change it in real time for me.
My whole concept since the early nineties building bikes, was building bikes for me, this is me and a bike as one unit – taking the holistic approach. In the world of mainstream cycling the whole attitude was, how can I get that bike to go faster? Then the rider gets on it and adjusts it to what feels good. I moved to a more holistic approach, it was bike and rider as one unit, and then, how can this bike go faster? This is more intimate, the shoulder support and the hip support – you have much more contact with this bike than a regular bike design.
You have always looked to innovate. You have adopted this approach throughout your career. So, was there only ever one way you could go about building this design?
Exactly, this isn’t new to me. I did it with the prone back in the nineties. With the pedaling action at the back, head first and a similar handle bar action to what I have with this bike. But the hands are much lower down like a traditional handle bar position. At the time I thought there is not enough micro-control. There are too many bones. I wanted to eliminate the bobble factor from your arms when you lock them up tight. It was amazing in terms of control when I rode in the nineties – and it is down to micro-movement – which is actually a rule for all bicycles – it isn’t about big wide movements. That is why I am very confident about how my bike will handle – I have done this before remember.
Have you had to make any compromises during the design process?
I thought to myself if an alien beamed down and asked the question – ‘how fast can a human being travel across a flat surface in the planet’s atmosphere? And how would he achieve this?’
As total blue-sky thinking, what would an alien do? He wouldn’t be constrained by bike chains, cogs, wheels – he would think what is the absolute limit of possibility, what the human bodies limitations are? Ultimately you could use cables or work out what the most efficient cable drive is, or even reinvent the wheel, or maybe even not use wheels.
You get a 2% advantage for your £10, 000 and a 20% advantage for £50. It doesn’t make sense to a man like me
And remember, there really are no rules with this competition. Ok, I have 6 months to do this, what is the standard fair throughout humanity for a bike. For example the gear changer. I was going to build a new gear changer to minimise the width, but ultimately I comprised because I worked out I can convert it and tuck it inside a zone that is between the hands and the knees and use a standard component that is not going to fail on you. There are factories out there with people constantly reinventing different mechanisms – why would I spend my time doing that when I can buy one off the shelf that works? That is an example of compromising for an existing product.
Ultimately the most important issue was – do not compromise on your frontal area. And do not compromise on your skin surface. Everything else had to take second fiddle, the road resistance, the size of the wheels, etc – obviously you can get the best you can in terms of your design, within the limitations of not giving anything away on the frontal area or the skin surface.
What are your views on the design of the conventional bike? How would you like to innovate it? And what would you change?
My view on conventional bikes is that they have been pushed across the line to conform with what the rules of racing are. Bike shops tend to follow the industry and the industry tends to follow the leads of professional teams and professional bike riders. The so called rules of the road are a certain handle bar width and no fairing; you never see a bike in the road with a fairing on it at all these days. Which is strange when wind resistance is in fact the biggest impediment to people riding bikes, that and hills.
So, if you put on a small fairing that doesn’t interfere with the handling of the bike, a lightweight small fairing similar to a moped actually reduces wind resistance by 20%. You could buy a cheap bike with one of those on and it would ride faster than a bike you would spend £10, 000 on. But you don’t see it on the road because it isn’t commercially viable. They are thinking, would I rather sell a £10, 000 bike or a £50 fairing. You ask the question qui bono? Who is benefiting – why not sell both? You get a 2% advantage for your £10, 000 and a 20% advantage for £50. It doesn’t make sense to a man like me.