So, when we tell you the range of the FX is 45km at a normal pace, you will get 45km or MORE at a normal pace on the FX, and so on for the FX MAX, SIERRA and SIERRA MAX. However, over the last few months we noticed that a few actors on the market (we won’t cite any names), were lying and inducing you in error with regards to the announced range of their bikes. Therefore, in order to really help you understand what you get when you purchase an electric bicycle we decided to write this small guide on how to calculate the real range of your bike and bypass the lies of some manufacturers.
The range of your ebike depends on a few characteristics. First, the energy contained in your battery. This is not your battery’s voltage on its own, nor its Ah capacity on its own, but the two multiplied together: Voltage x Capacity in Ah. This gives you the energy carried by the battery of your bike in Wh. For example, the FX’s standard battery carries 314Wh which corresponds to a potential consumption of 314W for one hour or 157W for 2 hours and so on.
Most ebike motors for road use have a continuous power of 250W, a peak power of 500W and a max speed of 25km/h. This means that upon accelerating, and for short periods of time, the motor will pull up to 500W of power from the battery, let’s say for a maximum of 10 seconds after which it will pull a constant 250W until the bike reaches 25km/h. Going back to our Physics of ecycling article, we can calculate how much power is consumed at 25km/h for a person of 75kg on an asphalt road:
We get a drag of 20N and a rolling resistance of 0.38N. This means that when riding your ebike at a constant speed of 25km/h you have to compensate for about 20.38N of force acting against your forward movement. Power is equal to force multiplied by velocity and 25km/h corresponds to approximately 7m/s. This gives a necessary power consumption of 142W to maintain this speed of 25km/h. Now, although part of the magic of bicycles is being able to enjoy great free wheel, which allows to ride power free without decelerating too fast, all periods of acceleration consume up to 500W. In addition, during these periods, the bike’s speed is lower than 25km/h. We have found through multiple tests and experiments that a factor of 20% represents well these losses.
Eventually, we can write that (Capacity (Wh) * Velocity (km/h)) / (Power Consumed (W) * Loss Factor) = Expected Range (km):
- For a battery of 314Wh, this gives a range of 313*25/(142*1.2) = 46km
- For a battery of 374Wh, this gives a range of 374*25/(142*1.2) = 55km
- For a battery of 482Wh, this gives a range of 482*25/(142*1.2) = 71km
These values depend on your weight, style of riding and environmental conditions (temperature, assist level, acceleration, free wheeling, etc) but give a very reasonable approximation of what to expect. We are working on an online calculator, taking all these variables into account, that will be available on our website very soon. In the meantime, this will give you a very good idea of what’s real and what’s not. For example, a battery capacity of 220Wh will only give you about 32km at an average pace, not more like some would like you to think 😉
1 – Switch on the battery and press and hold the mode button to switch on your screen.
2 – Once your screen is on, press and hold both the “+” and “-“ buttons to access the general settings.
3 – Press and hold the “M” and “-“ button to access the system settings
4 – Once in the system settings, tap “M” to scroll through the different settings. The speed limit setting is marked “LS”.
5 – Use the “+” and “-“ to adjust the speed limit which can be seen in the bottom left corner of the screen.
6 – Once you have selected a new setting, press and hold “M” to save and return to the starting screen.
Legal notice: You must comply with your local regulations to ride your e-bike on public roads, increasing the speed limit over 25kph in the EU will make your e-bike illegal to ride on roads without a license and registration. The limit should only be increased over 25kph for off-road use or in the case where your local regulations allow it.
Like a battery, a fuel cell cell harnesses a chemical reaction to produce energy in the form of electricity. More specifically, Hydrogen fuel cells generate electricity, water and heat from hydrogen and oxygen.
Fuel cells consist in an anode and a cathode surrounding an electrolyte called a synthetic polymer membrane which separates hydrogen and oxygen while only permitting the passage of certain ions (H+ or protons). Hydrogen atoms enter the fuel cell at the anode where they are stripped of their electrons. These electrons travel through the vehicle’s circuit to the cathode in the form of electricity. The positively charged hydrogen atoms (or protons) travel through the membrane to join with the oxygen and the electrons in order to eventually form water. Each individual fuel cell produces relatively low amounts of current and voltage and, like lithium-ion cells, therefore need to be stacked together in series and in parallel to reach the target voltage and max current required by the vehicle they are powering.
The beauty of hydrogen fuel cells is that you get electricity, heat and (potable) water as outputs with hydrogen and oxygen as inputs. Oxygen is abundant in the atmosphere while hydrogen is the most common element in the universe. However, hydrogen tends to bond very easily with other elements. Therefore, it has to be artificially isolated before being usable as a fuel through processes that are quite expansive and energy consuming.
Hydrogen used in fuel cells has an energy to weight ratio ten times greater than lithium-ion batteries. Consequently, it offers much greater range while being lighter and occupying smaller volumes. It can also be recharged in a few minutes, similarly to gasoline vehicles. However, Hydrogen fuel cells also come with a lot of drawbacks. First of all, hydrogen is mainly obtained from water through electrolysis which is basically a reversed fuel cell and takes electricity and water to produce Hydrogen and Oxygen. The source of this electricity can range from renewables to coal depending on where you are in the world, hence hydrogen extraction can be very clean or dirtier than a typical gasoline car. Nowadays, sadly, it is more likely to be the latter simply because of the way the majority of the electricity is produced on Earth.
Other issues are that storing hydrogen as a gas is expansive and energy intensive, sometimes as much as half the energy it contains, and even more so when it is stored as a liquid at cryogenic temperatures. In addition, it is highly flammable, tends to escape containment and reacts with metals in a way than renders them more brittle and prone to breakage. Eventually, although it is everywhere around us, hydrogen is hard, dangerous and expansive to produce, store and transport.
Fuel cells can also only operate with water, not steam nor ice. Therefore, managing internal temperatures is essential and heat has to be constantly evacuated through radiators and cooling channels which add considerable amounts of weight. Restarting in cold temperatures can also be very complicated and impractical in locations that often experience temperatures below freezing point.
To conclude, hydrogen fuel cells offer a potentially very clean, energy dense and easy to recharge energy source for vehicles and other systems, but are currently complicated, expansive and dangerous to operate. In comparison, Lithium-ion batteries, although less energy dense and slower to recharge, are as clean, much cheaper, easier and safer to handle. More specifically, cylindrical lithium-ion cells like those used in the SIERRA and the FX are very stable and safe to use. In the future, once the technology is sufficiently developed and the drawbacks mentioned above addressed, hydrogen could be a great solution to increase range and decrease charging time in electric vehicles. But for now, lithium-ion technology is the best solution to offer very practical and high performance ebikes and other vehicles.
This is exactly why we have decided to add wireless turn indicators to all the FXs we ever produced, for free!
Every FX will now be equipped with a wireless remote attached to the handlebar and an indicator module in its portable lithium-ion battery. Simply click on the right or left arrow on the remote to indicate where your FX will take you next.
Stock for the next batch is already going fast, don’t wait too long to get yours!
As most of you are aware, our 25% discount is also ending very soon. You can rest assured that it still applies to all purchases made through our website until it expires. This means that our next batch of SIERRA and FX is still covered by the discount until the 15/05. It is currently planned for delivery in September, although it will most likely come earlier than this as we are working very hard to accelerate our production rate and optimise our supply chain.
If you are thinking about getting a FX or a SIERRA, we strongly advise to make the most of the discount, particularly as our next batch will also have a limited stock.
We are always available and very happy to help you, so if you have any questions or requests please don’t hesitate to contact us.
Let’s start with the protagonist itself, the ebike, here we will have a look at the SIERRA in particular. The SIERRA is made of a full carbon frame which has to be structurally strong enough to support the sum of your weight, the ebike’s weight with all its components, and the weight multiplication and shocks due to bumps and other obstacles on the road. In addition to all the typical bicycle equipment (disk brakes, gears, chain pedals, wheels, etc) the SIERRA’s frame also has to carry a motor, a battery, an electronic controller and a computer. These components are all relatively heavy with respect to the frame of the bike but remain light once you add your weight to the equation, even for the skinniest of you.
The SIERRA is equipped with a torque sensor which measures how much pressure you are exerting on the pedals. In turn, it sends a message to the controller which calculates how much power from the motor is immediately required. At the same time, the computer scales the controller’s calculations with respect to the assist level you are set on. Eventually, the controller which is connected to the battery, opens a channel between the battery and the motor and allows high power currents to flow in a certain pattern so as to activate the motor and power your ride.
This then makes you go forward and pick-up speed. We will now focus on what is happening once you have reached a speed of 20km/h and are accelerating by 1km/h per second or reaching 25km/h after 5 seconds on a flat asphalt road. According to the second law of Newton, all the forces acting on the bike and yourself while you move forward are equal to your total mass multiplied by your acceleration. This can be written:
The forces acting on the bike and yourself while you are moving are:
- Your own, applied through the back wheel of the SIERRA: we will call it Fy and it is measured in Newton
- The motor’s, applied through the backwheel and the chain of the SIERRA: we will call it Fm and it is in Newton
- The aerodynamic drag, due to your movement through the air of the atmosphere, which can be calculated in Newton using the following equation:
D=1/2*Cd*p*V²*Awith Cd the coefficient of drag, p the density of the air, V your velocity and A your frontal area.
- The rolling resistance of the tyres on the road which can be calculated in Newton using:
Fr=Cf*m*gwith Cf the rolling resistance coefficient of the tyres on the road, m your mass in kg and g the gravitational constant g=9.81m/s², m*g is essentially the force in Newton exerted downwards by your weight on the bike.
First of all, we can calculate the drag. In a standard relaxed cycling position on the SIERRA, your frontal area is likely to be 0.6m² and your coefficient of drag: 1.15. The density of the air at sea level is 1.225 kg/m3 and your velocity is 20km/h which is equivalent to 5.6 m/s.
The rolling resistance coefficient of bicycle tyres on asphalt is equal to 0.004, assuming you are 75kgs, the weight of the SIERRA being 20kgs, your total weight becomes 95kgs.
So the sum of the forces can now be written:
with m your total weight (95kgs) and a your accelerations in m/s².
Also note that the sign of the forces in the sum depends on the direction these forces are acting. If they act in the direction of the movement, then they are positive, if they act in the opposite direction, they are negative. We can replace the variable with the values we calculated knowing that an acceleration of 1km/h/s is equivalent to 0.28 m/s²:
We know that the wheels of the SIERRA measure about 0.70m in diameter and therefore 0.35m in radius. We also know that torque is a force multiplied by a distance. Hence, the torque generated by the combined efforts of your legs and the SIERRA’s motor is 40*0.35=14 Nm. We can even get the total power by multiplying this by the angular velocity of the wheel, or the speed at which it rotates. We know that its perimeter is 2 * PI * Radius = 2.2m. As we are going at 5.6m/s, this gives 2.5 rotations of the wheels per second or an angular velocity of 15 rad/s (multiply by 2 * PI).
Hence, on a flat asphalt road, in order to maintain an acceleration of 1 km/h per second while being at a velocity of 20km/h, the total power needed from you and the SIERRA together is 15*14= 210W.
As the BOFEILI mid-motor of the SIERRA produces 350W of continuous power and more than 600W of peak power, at this cadence you will only be exploiting a third of the power of the beast. Depending on your assist level, you can either fully provide the 210W through your legs or entirely rely on the SIERRA, it’s your choice and that is the magic of electric cycling!
Do not hesitate to ask questions in the comments, we will be happy to answer them if anything needs to be made clearer!
It’s been a great adventure getting our bikes from paper right to your home and we are pretty sure that you won’t be disappointed! This also marks the end of pre-orders for the FX and the SIERRA. On the 15th of May, all 25% pre-order discounts will be discontinued. Our stock is also limited, so for those of you thinking about getting one of our great ebikes, now is the time 😉
Our mission to get commuters and cyclists beautiful, affordable, high performance ebikes is going better than ever, and we will keep working to get you the best, always!
Thank you all for your support!
When designing a new part or component, engineers use CAD (Computer Aided Design) software such as Solidworks or Autodesk Inventor. These allow to create shapes and patterns which aggregate to solid 3 dimensional objects. The CAD software then allows to save this object in the form of a STL file which basically maps the surface of the object with triangles. This file is then uploaded to the 3d printer which reads it and proceeds to create the object vertically layer by layer following different processes described below.
Extrusion deposition is the method employed by most desktop 3D printers and consequently the most widely used in 3d printing. Here, a filament of thermoplastic (most common) or metal is passed through a heated nozzle to melt, deposit on a surface and harden instantly. The nozzle turns the flow of material on and off while motors displace it according to the 3d coordinates contained in the STL file.
Another process consists in the binding of granular materials. Powders of materials such as metals or plastics are deposited on a bed. Powerful lasers or binding agents are then applied to it according to the model’s coordinates to fuse and harden the beads layer by layer, starting from the bottom and progressing upwards. Technologies using this process are Selective Laser Sintering (SLS), Direct Metal Laser Sintering (DMLS), Selective Laser Melting (SLM) or Electron Beam Melting (EBM).
Photopolymerisation is also an interesting 3D printing technique. Processes such as Stereolithography (SLA) are based on the hardening of liquid materials into solid shapes. Here, baths of liquid polymers with photosensitive additives are exposed to controlled lighting which leads them to harden. Again, this process is applied from bottom to top through little increments where the shape being built is slowly displaced downwards as new material is solidified. This technique allows to obtain smoother plastic surfaces and therefore reduce the need for part post processing (smoothening, etc).
In the end, 3D printing is a real revolution in hardware development. It allows to materialise designs at record speeds and with similar aesthetic properties to finished products. Of course, engineering characteristics such as strength cannot be similar to those in a properly manufactured products but they are sufficient to test shapes, details and configurations before moving to the factory machinery. In turn, 3D printing saves designers considerable amounts of time and money and enables smaller entities to come up with great products and compete with the big guys, often less inclined to innovate from their comfortable leading position.
Global population is growing which with urbanisation is causing population densities around cities to increase. In addition, personal transportation systems such as cars, vans and motorcycles are bulky and noisy. Add to that the fact that about a century ago, we chose fossil fuels over electricity (rightly so at the time), we now have a nice combo of polluting, traffic stimulating and impractical vehicles. As this has even become deadly, we urgently need something better.
At FuroSystems, we really think that the clear solution is electric bicycles. They are now powerful enough and offer sufficient autonomy to take a rider anywhere, around any city in the world, for multiple days. They are compact, fast, quiet and clean. This is why we decided to use our expertise to help accelerate our society’s transition to this amazing and fun mode of transportation. How? By making them better, more practical, more attractive and more affordable.
As with any great innovation, electric bikes have their sceptics, the main argument is that it’s essentially a way to cheat cycling, something for the lazy.
According to Steve Garidis, the UK’s Bicycle Association’s operations director : “It’s quite difficult to explain what [an ebike] feels like: you’re still cycling but it’s like being an Olympic athlete; you can go faster and longer; hills are less effort. The acceleration is quite fun, even for the most sceptical grown up.”
So yes, ebikes do make it easier. They allow older or handicapped people to go places they can’t anymore or never could, and ride with their loved ones. It makes commuting and cycling more manageable. However, they also allow everyone else to experience a new level of acceleration, speed and performance. They don’t remove the effort if you still want it, they just make everything better, more intense, it’s an enhancement of your physical capacities whether you are fit or not. For example, our bikes the SIERRA and the FX give you the option of riding them unpowered making them feel exactly like normal bikes, but they also allow you to multiply your acceleration, uphill capacity and speed, whenever you feel like it. To make it even simpler, they are a 250 W to 600W power add on to your body which you can choose to activate on demand.
Deciding to use an ebike for your commute instead of your car, scooter or moped is probably the best thing you could do today. No more pollution, no more noise, no more fuel, no more insurance and a healthier lifestyle. Folding bikes like the FX are also incredibly more practical, particularly when they are that light, while staying very powerful and offering great range, not far off from that of a 50cc petrol scooter.
Electric bicycles are the mode of transportation of the future, they literally solve every single problem you could think of in modern transportation and greatly enhance cycling. In addition, battery technology is close to making significant leaps forward with technologies such as solid state chemistry, super capacitors or 2D materials such as graphene. You can trust that we will be here to implement each of these advances in your FuroSystems ebikes as soon they are out!
A little eye candy for those of you that stayed with us to the end 🙂
So what is it? Its basic element is carbon, it’s made of 6 electrons, 6 protons and 6 neutrons and without it you wouldn’t exist, nor would any life on Earth. When you overcook your food or burn some wood, the residual ash is mainly carbon. Carbon fibers consist in these atoms being assembled in crystals and bonded in a direction that is approximately parallel to the fiber’s long axis. Each fiber is between 5 and 10 micrometers (millionths of a meter) wide, or 2 to 20 times narrower than a human hair. This configuration gives them a strong strength to volume ratio. Individual fibers are obviously relatively weak on their own but once woven together they lead to a very strong cloth.
At this point, carbon fiber is just a fabric similar to the ones made of cotton for your tshirts, only much stronger and much more expansive. To transform it into a useful and solid engineering material, the cloth is mixed with a plastic resin such as epoxy to form a composite also called carbon fiber reinforced composite. The manufacturing process usually consists in a technician laying the fibers on a mould, painting them with the chosen resin and then baking the assembly to obtain a part with the desired shape. The result is an extremely rigid and very high strength to weight ratio component.
Carbon fiber reinforced composites (CFRP) are about ten times stronger and 5 times lighter than steel and eight times stronger while 2 times lighter than aluminium. In addition, their very manufacturing removes the need for welds and allows for sleeker and smoother shapes. It is true that CFRP tend to be more brittle and crack slightly more easily than aluminium or steel. However, this is easily compensated through design by ensuring that the load necessary to lead to a crack will always be much larger (MUCH LARGER) than the greatest load your bike will ever experience during its use.
Also, the fact that carbon frames cannot be fixed once broken is a myth, they absolutely can, in a very rapid and discreet way as well. After all, if it’s trusted to make the wings of giant machines that fly hundreds of kms in the sky, costing hundreds of millions of dollars and carrying hundreds of people (that’s a lot of hundreds), then it can most likely be used to enhance your biking experience, and that’s exactly what we’ve done. Aerospace engineering at the service of happy riders!
This video details well the frame manufacturing process used by KOENIGSEGG and FuroSystems: