So I was flipping through this year's NASA Spinoff Magazine today and chanced upon an interesting story.
You may know that it was common for NASA astronauts to return to earth in a pretty dehydrated state with low blood volume. Because of the lack of gravity in space, the human body apparently thinks that getting rid of excess body fluids is the right course of action, and there goes all the orange juice, root beer and other geeky stuff you drank before lift-off. This is how the human body attains homeostasis, or equilibrium with the new environment.
In space, taking salt tablets mixed with water isn't even a preferred solution because water quantity is limited up there and astronauts don't find favor with the method. So story made short : An ex-AMES Research Center physiologist named Dr. Greenleaf takes interest back in the day and designs an isotonic electrolyte formula based on a specific ratio of sodium citrate and sodium chloride. While the rest of the stuff in it was patented, it had no sugar, no caffeine, no carbs, no added color. I mean, this stuff was really salty. After 15 years of development and testing, he gives his formula called "HyperAde" to astronauts, they love it, and since then, this is being used on NASA's space missions.
This isn't all apparently. The catch? During scientific research and testing, not only did NASA validate that this stuff beats water and common endurance drinks by appreciable margins, but they also found that it leads to a "20%" increase in cycling endurance on an ergo meter. The reason was attributed to greater increase in resting plasma volume compared with other control products. Dr. Greenleaf's white paper for NASA, titled "Drink Composition and Cycle-Ergometer Endurance in Men : Carbohydrate, Na+, Osmolality" can be read here.
So how did this technology end up in the hands of Wellness Brands Inc, a Colorado based company and metamorphise into what they call "The Right Stuff"? The product was launched in June of this year. It is being sold to cyclists, runners and other endurance athletes and Dr. Greenleaf is on the company's board of directors as inventor of the item.
You may be interested in reading this snippet from the '09 Spinoff Magazine. Enjoy!
If you read descriptions of Shimano's products, you'll often come across the words "cold forged aluminum", mentioned with great pride.
Forging is a metal shaping process in which a malleable metal part, known as a blank, billet or workpiece, is worked to a predetermined shape by one or more processes such as hammering, upsetting, pressing, rolling and so forth. Cold forming is a precision category of forging which does the same thing without heating of the material (room temperature), or removal of material.
Most of Shimano's products in the bike and fishing business utilize cold forming technology, which was established by the company more than four decades ago. It was in 1963 that Shimano introduced a cold forging plant to press precision parts for bicycles using dies and high pressure in order to form metal at room temperature. Plants such as these use presses, punches and dies that see very high working pressures, upto 1500 N/mm^2.
But why such specialized equipment?
The plasticity of aluminum at room temperature is low. The flow stress of aluminum decreases with increasing temperature. For alloys that are very easy to forge, such as 6061, there is nearly 50% decrease in flow stress between 700 deg F and 900 deg F.
Forgeability and forging temperatures of various aluminum alloys. Note that 810-900 deg F is the recommended forging temperature for 6061 alloy. Credits : Aluminum and Aluminum Alloys (ASM International)
Therefore, at room temperatures , because the flow stresses are higher, large machines capable of ramming and hammering the hell out of these alloys to get accurate shapes are needed. Of course, its more a delicate operation as opposed to the violence I have described above as great care has to be taken to prevent microscopic defects from developing in the cold forged piece, while it works at the upper limit of its strength.
On the other hand, because cold forging allows one to make parts without introducing the need for heat treatment and additional machining processes, it is an economical manufacturing method to produce precision, net-shape parts.
This is exactly what was needed by Shimano back in the day when it started designing integrated shift levers and gears that demanded high precision but which invariably suffered from the disadvantage of having a specialized and small market without much economy of scale. It has been mentioned that Shimano is one of the few companies in the world that can produce cold forged aluminum parts with close tolerances as those needed in the STI mechanism.
So how exactly did Shimano get around to having this precision, cost cutting technology? It turns out that the company has to thank a brilliant electrical engineer who basically re-created the entire company in the 1950's by helping it adopt the cold forging process, way before any other company in Japan at the time, even Toyota!!
Shuzo Matsumoto joined Shimano in 1954 with a dream. A graduate of the electrical engineering department of Osaka Prefecture University, he saw his mission as introducing cold forging technology to the replace hot forging then used. To achieve this goal, he was dispatched to the United States for 2.5 months by the company President, Shozaburo Shimano (died in 1958). In those days, only a limited amount of foreign currency could be taken out of Japan by any individual. Therefore, before departure, he was handed a lot of dollars obtained from the black market by Shozaburo and was simply instructed to "enjoy the trip".
An internal bicycle hub is an intricate planetary gear mechanism and is made of dozens of small parts. See, long before the derailleur became a staple in racing bikes in the 20th century, internal hub gears ruled the roost. In those days, these beautiful devices offered the first practical ways to shift gears on the fly. What a godsend!
In order to fully understand this beautiful system from a technical standpoint, we need to study the kinematics. or motion of the gearing action.
Click to zoom up the following one page article which explores the dynamics of the gearing in a 3 speed Sturmey Archer planetary gear hub. It explains how "gear ratios" are obtained in a planetary hub system by following some simple 'rolling contact' principles of gear motion. I borrowed it from my one of my favorite engineering textbooks. I hope this will make you appreciate the science behind bicycle transmissions. Also, when you get a chance, open up a hub and check it out for yourself!
In our last post, we looked at a quote from a Spanish traffic organization and proved that a cyclist cannot go airborne and land on the thirteenth floor of a building after a car collision.
Why I did a trajectory analysis is due to the fact that a cyclist-car collision is very different from a pedestrian-car collision as far as impact points on the car are concerned. Studies have found that not only do cyclists hit the car structure under different angles, but they also hit higher than pedestrians. In contract to pedestrians who mostly hit the bonnet and bumper of a car, the main impact location for cyclists was found to be the windshield. So in the analysis, I assumed that the windshield will elastically collide with the cyclist, and the cyclist will bounce off it into the air with a high velocity like a firecracker on an independence day celebratory occasion. In reality we know this won't happen, because the head will absorb the impact, bones could break, the car may dent, glass could shatter, and friction will ensure that there is a limit to how high the cyclist flies.
In order to avoid a disconnect between topics, I have attached additional collision literature today for a reading session over coffee. This paper is an interesting one because its an analysis of a real accident where a car collided with a little 7 year old boy on a bicycle in one of the most dangerous cities in the US - Camden, New Jersey . It was authored by Dr. Micheal J. Ruiz, professor of Physics at the University of North Carolina at Ashville, USA and his ultimate aim is to present easy techniques to estimate the initial velocity of the striking vehicle.
The paper presents the analysis by looking at the accident using two ways : 1) Simple momentum conservation using elastic collision with assumed vault distance and co-efficient of restitution close to one, 2) Collins speed formula - a slightly advanced analysis using quadratic kinematic equations and accounting for the co-efficient of friction on the road.
The paper concludes that the initial velocity of the car at impact was around 11-12mph. Yet, such a low speed appears to have been enough to send the young boy flying 10 metres or 32 feet away from the impact point, eventually fracturing the rear section of his skull.
I happened to come across this quote on some helmet advocacy website a few days back. I forgot to bookmark the darn site but had copy pasted this statement exactly as it was into a word file on my computer. Anyway, I was struck and bothered by such a bold claim. While it sounds scary, is there any real truth in it? 46.5 kph is around 29mph, which is a low speed for a vehicle. Despite this, the momentum of the vehicle is a hell of a lot considering its high mass with respect to the cyclist. So can the momentum transfer in the above collision really rocket the cyclist up to as high as thirteen floors before crashing to the ground? If such were the case, the cyclist could be in serious condition, even dead.
If you know your college physics, the topics to recall would be Newton's laws, impact and momentum transfer, conservation of energy, collisions and projectile motion. But hold on. Its a tricky challenge. There are many variables to consider : the masses of the three bodies, height of the cyclist, the gradient of the road, point on the vehicle first struck, orientation of the bicyclist before impact, the launch angle, coefficients of restitution and friction, and victim's behavior post impact (wrap, vault, forward projection, somersault etc).
Physicists and engineers across the world have come up with all sorts of equations to study vehicle-pedestrian collisions. They're interested in things such as - how one can devise a good comprehensive mathematical model that will approximate well the speed with which the vehicle first impacted the victim, or what the total throw distance of the victim would be given other data, or would the model ultimately validate real world behavior - questions of that nature. Such models could then be incorporated into manuals and computer tools that could be used by police officers and forensic investigators to catch criminals and help serve justice.
In America, most commercial buildings are 10 feet in height per floor : 8 feet head room, 1 foot above drop ceiling (pipes, electrical, etc.), and 1 foot for infrastructure (beams & support structures). Can a cyclist rocket to 130 feet in the air upon a collision? We may never know exactly, because not a single bit of data is provided by Traffico other than the car's speed at impact which is given to be 46.5kph=29mph.
Lets make an effort to find out.
1. LOOKING AT VIDEOS
Forget the theoretical part for a moment. Lets look at a couple of real collision videos involving a two wheeler and a car.
Here's a guy on a bicycle getting hit by a car. The latter was decelerating hard after the driver spotted the rider coming into his view but it was too late to stop an impact. Note how the right corner of the car impacts the cyclist first. The rider then hits the windshield and bounces off it before falling onto the road on the right side.
The victim is pretty lucky. He just gets up and immediately starts yelling his frustrations. I'm so surprised he didn't smash his head onto the ground. But hey, neither did he fly any higher than the car itself. Just a few feet. The car itself could have been doing 15 or 20 mph before impact.
Here's another video. This time, its a vehicle colliding with a motorcyclist who fled a red light only to meet his deadly fate.
If it had been a bicycle in the video, which is much lighter than a motorbike, it would have been thrown off a farther distance. The car was moving much faster than the first video. It could well have been doing 35 or 40mph before coming to an abrupt stop after the collision. The airbags must have surely deployed since the driver appears disoriented. The motorcyclist is shown spinning in the air at a stomach sickening angle before landing onto the hood of the car and bouncing off it straight onto the road, right in front of the stopped vehicle. Its anyone's guess how many bones he could have broken that day.
And finally, here's a simulation of a car-bicyclist collision. It was done by Crash Teams, the largest crash reconstruction company in the world.
All three of these videos don't show the cyclist being propelled to dizzying heights after the collision. At least not thirteen storeys high.
2. FIELD EXPERIMENTS
Jim Green is a triathlete and Professional Engineer with over 20 years of experience in reconstructing bicycle accidents. In the 19th chapter of his book "Bicycle Accident Reconstruction For The Forensic Engineer", a table of vehicle-bicycle collision data is presented to us. The analysis was done on the field by Rusty Haight and Jerry Eubanks who set up an experiment in which different kinds of motor vehicles were used to strike an exemplar bicycle with a dummy cyclist at various speeds.
Here's the field data that shows the linear throw distance of the dummy cyclist after impact.
Determination of the throw distance of a bicycle and cyclist at various impact speeds
I have highlighted some rows of data for cars close to 29mph. For example, a 1979 Honda Accord hitting the dummy cyclist at almost 27 mph in a 60 degree orientation would throw the rider some 58 feet. Although the field experiment did not measure for the maximum height of the cyclist in the air, I highly doubt that the dummy really went as high as thirteen floors for a throw distance of 58 feet. I don't believe that's what the researchers really observed.
3. PROJECTILE MOTION
Coming back to physics, the cyclist on impact would be a projectile because his motion is only governed by gravity. But can we use the equations from projectile motion to find out what his height achieved could be in an ideal case scenario?
Lets use some simple assumptions like the following before any calculations :
a) the cyclist is a particle of mass 70kg b) the head-on collision is elastic c) the bike is immediately separated from under him after impact d) the cyclist hits the windshield and is launched forward at an angle e) during the collision between him and the car, there is zero effect on the velocity of the car itself due to its very high mass and that all the car's impact velocity is transferred to him f) the car comes to a complete stop just after impact, leaving the cyclist with the forward motion velocity g) there isn't much deformation to the car, or injuries to the cyclist AT impact and the co-efficient of restitution is essentially at or very close to 1. 9) the analysis is strictly restricted to a two dimensional plane, with no regard for the z dimension.
For head-on elastic collisions, the velocities of the car and cyclist would be :
Assume the car has mass m1=2000kg, and the cyclist has mass m2=70kg.
v(car) = 13m/s (46.5kph, given by Traffico).
So, v(cyclist) = 25.12 m/s.
According to the equation for maximum height in a trajectory, we find that range is shortest and peak height is maximum when the launch angle is exactly 90 degrees with respect to the horizontal. This is because sin(90) = 1.
Since we assumed that the cyclist hits the windshield, lets give him a launch angle of 80 degrees. Solving :
With air resistance factored in, the cyclist would make a 30.82 m max height, or 101 ft. Add the height of the car's impact point to this figure and it still gives us something under 105 feet. This height, given such idealistic assumptions we made earlier, is still lower than 13 floors. In America, commercial buildings are usually 10 feet in height per storey. 13 floors would be about 130-140 feet. Hence, in the real world, one probably cannot come close to anywhere this high. Real world videos or simulation show us different and complicated outcomes. There usually isn't a good bounce between the car and the victim just after collision. Moreover, kinetic energies could be absorbed in the collision as heat, light, or deformation energy and the neither does the cyclist and the bike follow ballistic trajectories like a cannon. Lets remember that the cyclist sits on a bike and that fact coupled with how he impacts the car are very likely to influence how far or high he's thrown. Hence, I cannot validate the calculations above for real world observations. I may believe it if you're talking about a collision on the surface of the moon where the acceleration due to gravity is 1/6th that of the earth. Or if we're talking not about a human cyclist, but a ping-pong ball.
CONCLUSIONS
The idea that a cyclist will launch as high as 13 storeys seems like a wonderfully wacky proposition. I support the wearing of helmets for protection but don't support the spreading of false information by agencies in putting together a helmet wearing agenda.
As an end note, I just thought of something in my hindsight. Maybe Traffico is right. What if, in Spain, the 13th floor of a building is considered so unlucky that there is no 13th floor at all in its elevator's options.
What Traffico then must have actually meant through their quote is : You're one unlucky bastard to be hit by a moving car at 46.5kph!
Concluding video presentation : James Green, PE discusses bicycle accident scene investigation from the perspective of a forensics engineer.
A lot of people these days question the age-old triangulated design of the bicycle frame. They think bicycle design is "dead" just because nothing has changed for a close to a century in relation to this structure, the biggest element that stands out when any observer sees a bicycle. And designers around the world are increasingly trying to break free from this constraint and come up with the most bold, radical designs. Some are successful for a while, others are hype that never deliver. Yet, the classic structure has endured through all the competition.
But its nice to ask why, or how this simple design has stuck with us for more than a century. 1887 to 2008 is 121 years!
See, there's a sound engineering principle behind it. Let me explain.
A structural member is weakest when it supports a load which tends to bend it. We all know that. If this member is propped up from below, the load is carried in compression, and much more load can be carried. Still better yet is an arrangement that is strengthened by a cable such that it is in tension when applied with a load. This is the triangulated structure and it is the lightest and strongest structure arranged in such a way that its members are all in tension or compression, but never in bending.
I'm not a historian but I reckon that this brilliant idea might have made its way from age-old bridge and roof design somehow into bicycles. And people soon found out how they could have the lightest structure possible, which is strong at the same time to resist the forces encountered on riding.
Most, if not all, bikes we see these days are derivatives in some fashion or the other of this classic frame structure. The bike may have a few bends and curves here and there, but the fundamental principle still stands. To get a perspective on the road bike business, it is partly around these minimal changes that bicycle companies try to make money off you.
So, if anyone can come up with an alternative frame design that does the job better, without diluting the advantages of the original truss frame, we'll see something new. Until then, keep crying...and pass the hanky. (Note that some folks tried to extrapolate the triangulation to the fork as in the Pederson Bicycle... see below. Yet, interest in these bicycles also diluted with time)
In it, the author talks about the basic premise behind a diamond truss frame that we all commonly ride around, its drawbacks (which we can witness through all the pictures of broken steerer tubes & forks) , and what generally is expected out of a sensible bicycle frame structure. In the following short sections, he quantifies some of the peak forces experienced by the frame at various points, and gives tips on how to set up instrumentation to measure these stresses, both for folks with the equipment to do it and for those who don't have the money.
To put a bottom line to this post. there may be many fancy conceptual ideas floating around on the internet out there that make headlines and often bring much excitement. But if the resulting machine cannot ride properly or snaps under the application of forces, its not only useless but also dangerous for human use. In this regard, it violates the basic canon of engineering ethics which states something like : "Engineers shall hold paramount the safety, health and welfare of the public and shall strive to comply with the principles of sustainable development in the performance of their professional duties."
Mechanical Engineering researchers Y. Champoux, S. Richard and J. Drouet from the University of Sherbrooke (Canada) aim to help bicycle manufacturers study the dynamic behavior of bicycles so they can understand the real implications of their design in actual riding conditions.
Presented below is a paper they did on structural dynamics and it had appeared in the Sound and Vibration Control Magazine. The components and the frame of a bicycle are subjected to time-varying force excitations imposed by the cyclist and by the road. Its dynamic behavior becomes an important issue, because it is directly linked to the bike lifetime, maneuverability, efficiency and comfort. The researchers describe the bicycle structure in terms of its natural characteristics which are the frequency, damping and mode shapes - its dynamic properties.
I've often read that some of the most creative ideas that turned into winning products were first sketched out on table napkins. The iBike Power Computer was no exception either back in 2004, according to John Hamann, CEO/engineer of Velocomp LLP - a sports technology company based in Ennis, Montana.
The iBike computer is quite different from others. Affording portability and lighter weight to its user, it churns out an impressive array of readings from power, wind speed, road inclination, aerodynamic drag and even frictional losses in your bicycle's drive train by applying Newton's Third Law with the help of two inexpensive solid state sensors - an accelerometer and a wind speed sensor (also called an anemometer).
Velocomp consulted Protomold, a company specializing in automated Rapid Injection Molding for prototypes and commercial products.
Plastic injection molding uses plastic in the form of resin pellets that are loaded into the hopper of an injection-molding machine. A heated barrel on the machine melts the material and a large screw forces the melt into the mold. The material cools and solidifies. The machine then opens the mold at its parting line and ejector pins push out the part.
Rapid Injection Molding automates the design and manufacturing of molds based on 3D CAD models that have been uploaded online. This automation typically cuts lead times for initial parts to one-third that of conventional methods. Naturally, cost savings vary with the number of parts being produced, but rapid injection molding can have a substantial cost advantage in runs of up to thousands of parts.
Protomold produces quality molds using advanced aluminum alloys and precise, high-speed CNC machining. Parts can be molded in almost any engineering grade resin, at substantial cost savings compared to conventional prototyping and production methods.
Protomold provides us a case study of the design challenges faced by Velocomp and how they went about assisting them in creating a finanically feasable solution. One of the highlights of this partnership is the following statement from the case study:
"Protomold has been an important part not just of the iBike’s success, but of the business venture as well. With a partner like Protomold, we don’t just offer a better product; we can also change the way we do business as well. We may be small, but we’re doing the same thing that some of the best companies do: turning raw materials into cash faster than the raw material bills come due. We could wait 12 weeks for large orders of parts to ship from China, but instead, we keep a very small inventory and get parts as we need them from Protomold and our other US suppliers, which lets us be both fast to market and cash flow positive at a very early stage.”
Read the case study here or for actual PDFs, click here, and here (all courtesy of Protomold):
Not only because he has a big cypress-framed machine shop with so many cool toys in it somewhere in Georgia [See Map] and that he chose to build and name his design Zero Gravity, planting a perception of it in the market that this Titanium CNC'd gizmo is supposed to make you fly weightless in air when its actual function is to bring a bicycle to a grinding STOP!
Excellent.
In comes the fortune, the fame and the lusting customers.
Thats not so much what I'm interested in. You see, when Ted is not designing brakes, he works on another one of his inventions, only that this is way cooler than the brakes.
Ted Ciamillo has a vision, and much of it is somehow connected with deep, I mean deep, water.
He wants to be a Luno Sapien, a self propelled deep water creature!
Naming this side obsession The Subhuman Project, he has designed and built a 15-foot, 2 ton human powered submarine that he will pilot himself in November 2009, all alone and 6 feet below the surface for 3000 miles from Florida to the African coast.
Is is said that this endeavor, if successful, will break some 15 world records. It is also promising to yield tons of data to researchers about unheard of alien creatures deep in the Atlantic Ocean.
That is striking. I truly dont understand why everyone wants to go into outerspace, and spend billions of dollars looking for so called Alien lifeforms when there are hundreds, perhaps thousands of them, right there beneath our feet. They are colorful, weird in shape, don't live off sunlight and don't look like anything we can imagine.
The key component of this submarine happens to be a fiberglass monofin called Lunocet, the biomimetics inspired technology that mimics a dolphin's tail ditto. He employed the help of Dr. Frank Fish (what an appropriate name!), a professor of biology at Westchester Univeristy, PA in order to get the CAT scan data of actual geometries from real fishes, which he then translated to a CAD system which gave him his surfaces and all the manufacturing tool paths.
What finally came out was a system of carbon fiber hydrofoils pivoting about an aluminum and titanium baseplate. The Lunocet...tada!
For you engineers and those interested who want to go more in-depth on that phase of the design, click here.
Ted's entire Subhuman Project has its own website, on which you can read and watch some really cool videos of Ted at the shop. Click here.
And finally, Lunocet, Ted's monofin, also has its own website so you can navigate there if you'd like and read more about what it is and how it works.
I have a set of Zero Gravitys on my bike [sheepish smile]. Now I truly feel complete, like being part of a bigger vision, even though the brakes are probably as good as any thing else out there in the market.
Repoxygen is the tradename for a type of gene therapy that induces controlled release of erythropoietin (EPO) in response to low oxygen concentration. It is has been developed by Oxford Biomedica to treat anaemia. It has been developed in mice, is still in preclinical development and has not been extensively tested in humans [Wikipedia].
Basically, using hormones and other drugs to get dope into your system could be a thing of the past. Repoxygen, although hard to obtain, uses the natural abilities of a virus to deliver a therapeutic gene to an anemic patient's DNA. That gene will have the encoded protein, erythropoetin in it. Since this gene is similar to the patient's original gene, the 'camaflouging' is hard to detect.
"Mice engineered to have extra copies of this gene hopped onto a treadmill and, without ever having trained, ran about twice as fast as the unaltered mice. The extra PPAR-Delta improved the ability of the mice's muscles to use fat molecules for energy, and it shifted the animal's ratio of muscle fiber types from fast twitch toward slow twitch fibers - a change that would improve muscle endurance in people as well."
As far as I have learnt in biology, fiber ratios are genetically determined. But this form of gene quirk can blow all that out of the water. Now you may not even need to exercise to up your performance.
The dark question lurks : Are any athletes using repoxygen at the Olympics?
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