29 How Much CO2 Do You Exhale While Cycling?

When you're on your desk reading this new post, assuming you are not too excited, you might be very likely inhaling a shallow volume of about 0.5 liters of air and exhaling the same amount in every breath. This is the average tidal lung capacity of a male, shown in the figure above. In females, that's about 0.39 liters. We can assume you have a resting HR of 70 (typical) and you breathe 12-15 times in a minute.

Let's compare this to bicycling.


BICYCLING : CO2 ESTIMATE FOR A 5 MONTH COMMUTE

For a cyclist on his bike during a commute, heart rate and breathing rate increase, and they begin to utilize more of their lung capacity than the person at rest.

The inspiratory capacity of an average human is 3.5 liters of air per breath. If one emphasizes complete expiration following that, you get about 4.5 liters of air per breath.

A good assumption could be that for the typical bike commute, a cyclist does not approach the above extreme values unless in strenuous biking mode. So let's say this cyclist is at about 75% for both, which is still a high fudge factor.

Therefore, he inhales 2.6 L and exhales 3.4 L of air per breath. Also, breathing rate for such moderate exercise at steady pace can be assumed to be about 30 per minute.

Why the difference between inhaled and exhaled air? There is a residual volume of air in the lungs that you can never expire out, and remains in the lungs even after maximal expiration. Aahh...

Respiratory quotient is the ratio of CO2 eliminated to that of oxygen consumed. A normal value of this ratio is 0.8, where 0.7 is for pure fat oxidation and 1 is for pure carbohydrate oxidation. Literature also has it that for every unit volume of air inhaled, only 5% of oxygen is actually extracted by the body.

Thus, for the cyclist in our example, this means that :

Volume of CO2 exhaled per breath = 0.8 x (.05 x 2.6 L) = 0.8 x 0.13 L = 0.104 L
Volume of CO2 exhaled per minute = 0.104 L x 30 breaths/minute = 3.12 L

At standard air temperature and pressure, density of CO2 is 1.98 g/L. Therefore :

Kilograms of CO2 exhaled per minute = (1.98 g/L x 3.12 L) x 0.001 kg = 0.0062 kg

Extrapolate this according to the length of commute. A 30 minute commute will then involve 0.186 kg of expired CO2, 1 hour will see 0.372 kg and so on...assuming everything in our system behaves in linear fashion (think of what happens if the subject stops for a breath at a traffic light or at a convenience store?).

The bottom line :

Say this cyclist is being very conscious about himself by not driving his car. If he commutes for 5 months a year, for a round trip distance of 10 miles every working day of the week, at 15 mph on a flat path, he will expire about :

5 months x 22 days x 40 minutes of cycling x .0062 kg CO2/min = 27.28 kg of CO2


BICYCLIST VS CAR : THE 15,000 MILE ESTIMATE

If you want to compare bicycling with driving a car, then use the industry's 15,000 mile average. In 2009, a Toyota Prius, one of the better cars around in terms of emissions, generated about 3810 kg of CO2 for 15,000 miles. For the cyclist riding the same total distance at average 15 mph :

(15,000 miles/15 mph) x 60 minutes x .0062 kg CO2/min = 372 kg of CO2

This is a considerably lesser estimate than the vastly exaggerated number from a blogger named Ronnie Schrieber.

Schrieber wrote recently on his blog that a cyclist in aerobic mode gives out 0.081 kg/min of CO2 and so for 15,000 miles, a compelling 4,860 kg of CO2 or 5.34 tonnes of CO2 would be expired!

He compares this to the 2009 vehicular average of 8 tons of CO2 emissions and claims this is a huge figure for bicycling, hence there's not much of an environmental incentive for riding.

While one can debate how green bicycling really is by looking at the entire stream of what goes into the bicycle and into the human engine, it must be said that Schrieber's figure for CO2 production during cycling makes little sense. 5 tonnes of CO2? That doesn't sound reasonable so I'll ask him to check his numbers again.

What do you readers think? Does expiring CO2 have any impact on the environment? Say you're riding your bike at a charity event with 1000 other cyclists, then each minute, using my numbers, some 1500 kg of CO2 will be expired all over the countryside for 4 hours of riding. I would think it wouldn't matter, as the carbon in the CO2 had to come from somewhere initially and the cyclists are returning this amount of gas back to the environment. Its called recycling.

Come discuss.

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0 Saturday Stupidity XI

Tour of the Mountains Of The Moon

Annual Ride Report

This year we decided to do our annual spin to the mountains of the Moon in the fall as we had to finish our trans-Antarctic unicycle expedition in February, so we could get to see the mating ritual of the Campagnolo Penguin.

Peter Ptarmigan, Giles von Rundstedt and I headed off naked at dawn from the hotel and for the first 100 miles we had to battle our way through vast herds of Wildebeeste. Off to the left we could see a Tyrannosauras Rex stalking an insurance salesman and the sky was full of the sounds of rutting American Presidents. Presently we began to climb the Allthingsmust Pass, which starts off with a gentle 27% gradient but gets gradually steeper until at 35,000 feet we had to put on our oxygen masks.

We then began some serious climbing and as we were running out of fuel, we borrowed a bucket of Hershey bars from a passing Stealth fighter pilot. While we were eating them some yellow-tailed Lammermuir vultures passed by with loud squawks and we just missed being hit by a Pterodactyl who was carrying Paula Jones in his beak.

At 120 miles we stopped for our morning break and then descended the 45 miles to Allo Palto. Giles’ tires were so hot that when he got to the bottom they melted the tarmac. I was a little disappointed as due to a speed wobble I just failed to break the sound barrier, a feat which I have only managed on 14,157 occasions. We then went into a straight boring 237m stretch and stopped for a photo.

We popped into Paris for a large lunch on the left Bank with my old restaurateur friend, Marcel Mitterand, with whom I have been eating for 87 years. We then did a quick loop through Berlin and started on the foothills of Everest. Half ways up we passed Rudy Messner who was snowboarding down, surrounded by a huge herd of winged lesser spotted Aardvarks. He stopped briefly to have his picture taken with me and continued on his way.

I refused to sign an autograph for him as he had no technical qualifications and was dosing himself illegally on huge doses of snakeoil and lunar green cheese. Off to the left I could see the remnants of Alexander the Great’s army eating cookies and on our right there was a brown dog.

After a quick foray over the top of Everest we quickly climbed Kilimanjaro and as the sun was falling, had a lash over Mount Fuji, swooped down to the Dead Sea and arrived in time for dinner in Manuel’s restaurant in Tijuana. 14,157.12 miles, 135,000 ft but I never mention average speed as it would make you all feel even lousier than you already feel having read this.


The above was a piece written by Garry Lee, meant to be travesty of Jobst Brandt's legendary ride reports.

FOR PREVIOUS INSTALLMENTS OF STUPIDITY, SEE :

Saturday Stupidity I
Saturday Stupidity II
Saturday Stupidity III
Saturday Stupidity IV
Saturday Stupidity V
Saturday Stupidity VI
Saturday Stupidity VII
Saturday Stupidity IX
Saturday Stupidity X

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12 How The Copenhagen Wheel Works

One of the prime points behind the marketing of Copenhagen Wheel was its regenerative braking capability. Back in January, being the curious cat that I was, I wondered whether the design would be practical for Copenhagen where the outlook for 2012 is in establishing biking superhighways and such.

The question posed by me was how many stops it would take a cyclist to recover at least 10% of the total battery capacity in the wheel. My argument was that if it was a good amount, then it may make sense in crowded city riding conditions. With biking superhighways, number of stops may decrease so would regenerative braking be a much sought after feature then?

Recently, Christine Outram of MIT's Senseable Lab wrote to me clarifying the working of their design. From her, I learned that the wheel they showed at the Climate Conference was actually prototype number 2, with an off-the-shelf motor selected due to their time constraints. After the Conference, the team began their prototype 3 design phase to custom design the hub motor in order to make it smaller, lighter and more efficient. Through custom building of parts, she claimed that the hub would end up at about 2/3rds of the current size and weighing 3.5 kg.

I also picked up on some other important things from her email. For those who want to know how the wheel really works during pedaling, read on.

1) Using the bicycle : When cycling, the rider can choose one of three motor assist modes : low, medium and high. Each mode represents how much the motor is supplementing the cyclist’s cycling input (eg: effort x1, x2, x3) as calculated through our torque sensor.

There exists a sleeve-style mechanical torque sensor to measure the amount of effort the rider exerts as well as the speed and direction that of applied pressure. The readings from the torque sensor direct the motor on how much to supplement the rider, based on the motor assist mode the rider has chosen. Similarly, when the rider wants a workout or to recharge the batteries, they may choose a low, medium or high ‘exercise’ mode. Here, the rider is working against motor eg: effort x (-1), effort x (-2), effort x (-3).

2) Battery life in motor assist mode : Christine provided me some sample calculations to calculate the battery life. Typically, a flat city commute of 2 km will make a 70 kg cyclist expend 31 Watts of power. This distance can be covered in 8 minutes.

So if the motor assist is set to times two, the same commute mentioned above can be done in 4 minutes. In this case, the battery can be expected to last 8 hours on a single charge.

The same commute but with a 0.01 grade slope (gentle up-slope, 1 in 100), which is common in cities, requires 70Watts of power. This is a more likely scenario to use the motor assist mode. If set to times two, the batteries will last just over 3 hours and 50 minutes.

If the motor assist is set to times two, a rider can climb a 0.05 grade slope such as in a hilly city, like San Francisco, with the same level of effort and at the same speed as he or she would typically apply on a gentler 0.01 slope.

3) Battery charging in exercise mode : Let's consider the same commute distance. If the exercise mode is set to times two (the same commute will require twice the effort), the rider must provide 140Watts, and can burn 6.7 kJ (16 food calories) in his or her 8-minute commute. Additionally, if on exercise mode times two, discharged batteries will be fully charged in 5 hours and 30 minutes.

Note that the above points talk about the charging and discharging of the battery in pedaling mode, and not regeneration through braking. I hope we can get further clarification about that aspect from the team.


Christine stated the goals of their design as follows, in her own words :

"1. Providing ease of usability. Most other e-bikes on the market have bulky battery packs, are hard wired and are not able to be retrofitted in an existing bike.

2. Creating an elegant design where all components can be packed into one hub.

3. Augmenting the bicycle with small amounts of technology to encourage people to cycle - hence the social and data networking aspect. It may not be a motivator for everyone, but the electronics will continue to get cheaper, and if it convinces some people to ride a bike, then this is great.

4. Pushing the research agenda of the lab, which includes understanding how distributed sensing in cities can help us understand a city's infrastructure, how it can influence and promote sustainable behavior and how we can contribute to the design and development of sustainable places. This research agenda is also about imagining a future, 10-15 years from now, when these technologies will be much improved and fully integrated into our lives. Through this vision, we attempt to create leapfrog urban demos. in the present day. Hence, the construction and demonstration of the Copenhagen Wheel, which was made possible through bringing together from a variety of backgrounds including architecture, urban planning, computer science, network analysis, interaction designers, sociologists and mechanical and electric engineers."

Good stuff?

ADDITIONAL READING :

Practicalities Concerning The Copenhagen Wheel
Boston : From MIT, A Quantum Leap In Bike Mechanics

* * *

1 Carbon Bike Customization From Rouse Bicycles

Chris Cornetto, a resident of Austin Texas, has been a long time reader of my blog. He has, in the past, gratified the vanity of my work by saying that he used my blog for 'research'.

While spending copious amounts of time on my blog is not good for your health, Chris put such research time to good use by starting up bicycle business with a friend. His new venture, Rouse Bicycles, will provide fully custom painted monocoque frames made of Toray T700 carbon fiber (see material specs).

The starting price for their first release, called Alter Ego, is $1800 for a simple two color paint scheme. Note that this paint can be anything a customer wants, i.e any color and any design, even with your name on it. If a full build is desired with components, that can be done too. Their only requirement is that the 'Rouse' brand name appears on the down tube and a Rouse identification badge placed on the head tube.

An Alter Ego build for "internal use" was recently shown on Facebook weighing just 15.5 pounds.

Chris holds degrees in Geology and management and has more than 15 years of experience working in the chemical industry. He has spent the past four years promoting raw materials for use in fiberglass and carbon fiber composite applications. So I suppose I wasn't surprised by the length his company has taken to be transparent about their product's safety.

Now there exists a European safety standard for racing bicycles approved by CEN, called EN 14781. It specifies safety and performance requirements for the design, assembly and testing of racing bicycles and sub-assemblies, and lays down guidelines for manufacture's instructions on the use and care of such bikes. It also applies to racing bikes intended for high-speed amateur use on public roads, and on which the saddle can be adjusted to provide a maximum saddle height of 635 mm or more.

To those interested, Chris provides some relevant information on what his numbers were from the battery of tests performed under this standard. Its on a rare occasion you get to see such information from a bicycle company. I put them in a table for easy digesting :


Chris does face a tiny challenge in that he doesn't have much information to compare these numbers against. He told me he referred to Damon Rinard's frame deflections database but Rinard's table lists deflection numbers for metal alloy frames. He also referred to some frame stiffness values for the models listed in this post but those do not list deflections and German Tour magazine carried them out with possibly different test procedures.

If you wish to help interpret his test results against comparable frames and testing protocols, give him a shout! Let's all learn what these numbers really mean.

An example setup shown for the mass drop impact test specified as a requirement in EN 14781. Image courtesy : Zen Composites.

* * *

12 Jobst Brandt : Part V

Continued from Part IV

The following correspondence completed my interview of Jobst Brandt. In this final section, I asked him what his opinions were behind being famously anti-helmet. I also dug a little deep into the criticisms of his book by experts in the bicycling field and asked him what he thought about some of them.

In the end, I must say it was a pleasure chatting with him. Certainly, a few rapid fire Q&A's will not do justice in coming to understand the kaleidoscope of his bicycling philosophy. So I'm grateful to him for being the patient customer he was for this small period of time and co-operating with me in this wonderful idea.


31. What is your stance on one of the longest running debates in cycling? Pro helmet or anti helmet and why? For sometime now, people have been saying that helmets are inadequate because they do not protect against twisting forces. These days, helmet manufacturers are actively pursuing the design of "anti-rotational helmets". For instance, LAZER helmet has an interesting video and the host is Dr. Ken Phillips who gives an overview of the research he has been doing in helmet safety. Can this appease the complainers?

JB : That is a classic of missing the point, to just look at motorcycle helmets and see what is needed and useful, something that is not applicable to bicycling for the size, weight and lack of cooling. If you look at current helmets, they are a thin mesh of Styrofoam with no structural integrity. The LAZER project is barking up more religious belief trees. The video is a great sham.

I avoid helmet discussions because they are a religious belief. There are no realistic tests and all the people I know who crashed with one received severe head injuries as bad as if they had no helmet - usually skull fractures in the face. In contrast, I and my fellow riders have crashed often and not gotten head injuries other than a scrape that drew a bit of blood.

As I pointed out, Muhammad Ali's glove has far more cushioning than a bicycle helmet, yet it was possible with a mass far less than a human skull for him to deliver knockout punches, protection against which the bicycle helmet is touted.


32. Interesting. You always have some strong reasons behind certain viewpoints, such as the one against helmets. My readers and I were also fascinated by your rationale for choosing yellow paint on your bicycles.

JB : I suppose I'm less fashionable than most people, but I think good fashion is also the most useful design, something we don't see much these days, primarily in the cars and houses we build. The boom-box in cars is a great example of this. Most cars have four exhaust pipes and a lot of other non functional features as it looks and sounds different. Bicycle helmets are a strong fashion statement with their blowing flame shapes like hot rod cars.


33. One of my final questions to you concerns your book The Bicycle Wheel. Can you briefly run us through why you had this work published? Was it out of a strong desire to fill, perhaps a void, in the understanding of the wheel? Or did someone solicit you to write it?

JB : No one solicited anything, with nothing being known about the subject and with the total faith in bicycle mechanics to be doing the build and repair the best way possible. As I mentioned, there was much doubt when the book came out, even from some stodgy engineering professors who felt passed over by a mere bicyclist.


34. The reviews of your book are varied. I believe there are quite a number of people who think that you've done a great service in writing this, others think you're plainly against modern bicycle wheels and expected something more in a book that is titled "The Bicycle Wheel".

JB : The reviews I read gave the impression that I explained about what people want to find... a justification of their expensive "modern" wheels. Meanwhile, the essence of how wheels work and how to build durable ones hasn't changed. It is the website folk who are testy and nasty as thy look for justification of their expensive, unreliable and non metallic wheels, something they don't find in my book. Their criticism is similar to the bicycle helmet advocates who attack anyone who doesn't wear a helmet when bicycling. If you watch rec.bicycles.tech you may have seen the videos and stories of collapsing and disintegrating "modern" wheels in racing and touring. I don't want to write a justification of these wheels and dilute the essence of what makes reliable wheels.


35. What about other, more notable critics? Did you ever have a chance to look over John S. Allen's review of your book on Amazon? Mr. Allen is a technical bicycling consultant with an engineering degree from MIT. He's an expert witness and has authored multiple books on bicycles, commuting and repair.

For your convenience, I'll bring that snippet to you. Mr. Allen wrote the following on Amazon back in June, 2005 :

"There is one serious error in Brandt's book, and I am astonished that it has not been corrected through 3 editions. A graph, on page 39 in the 3rd edition, shows the change in spoke tension with lateral loading of the rim. The left spokes are shown to go into compression. They can't, as they simply flex once they are slack. It might also be asked whether this graph reflects the influence of spokes that are differently stressed as the load is applied at the bottom of the wheel. To do so would require a more complicated mathematical model than I think Brandt was able to command.

I also disagree with Brandt's advice to tension spokes until the rim begins to deform. It can then deform further due to increased stresses during riding, and loosen the spokes. I have seen a new wheel which failed after a few miles for this reason. Spokes should be tight, but should leave a margin of safety. If the rim deforms before the spokes reach their optimum range of tension, then they are too thick for it, or it is too weak for them.

I would really like to see this book updated with today's more sophisticated finite-element analysis, including analysis of stresses in the novel low spoke-count wheels. But for people who are willing to build conventional wheels -- the better choice anyway for most cyclists -- this book is a valuable and fairly comprehensive reference. "

Your thoughts?

JB : I recall that item from years ago. I explained that the graph mentioned actually plotted spoke tension of left and right spokes independently and then superimposed the two graphs because they use the same axes, but both do not do what is shown. In fact, part of the continuous curves show spoke compression that does not occur. The purpose was to show the response of spokes to side loads rather than to follow them to the limits evaluated.

I explain clearly in the book that when deformation occurs, the wheel is too tight but that there is no permanent damage that cannot be recovered by reducing tension. It is a method of finding the upper limit without a having a tensiometer.

I found much of his criticism in the same vein as I have heard all along. No one ever wrote about this subject (hence the name of the book) and when some technically minded folk see the book, they feel cheated for not having had the first stone to throw in this forum. They don't say what they would have written or explain what their perception of the stress/strain graphs would have been. They just say what I wrote is mostly wrong and let it ride there. I don't feel compelled to respond to these complaints because they are largely baseless.

As you see, Allen believes the current wheels are "today's more sophisticated FEA" as though mathematics had changed. That's a shot in the dark because it doesn't explain what would be different and why. That is because there is no difference other than the software being more available than when I did the analysis. The results would not be any different.

The book has been reviewed by enough engineering experts to make me sure the analysis is correct. As I said, the critiques are sniping because the implied other solution, the "correct" one is not shown. The reader is left to wonder what the implied correct solution is.

I included reference to Prof. Karl Wiedemer's analysis (Cologne Tech, Germany) in the bibliography. He wrote his finite element work at the same time I wrote the book, and have a pre-print of his technical publication. I also visited him in his home in Siegen and gave him a copy of my book about which we talked at length.

The interview ended here.

* * *

This graph on page 39 of the book The Bicycle Wheel was critiqued by John S. Allen, a consultant and expert witness in bicycle accident lawsuits. These curves show change in spoke tension and the force required to displace the rim and cause these tension changes. Courtesy : Jobst Brandt.

An excerpt from Page 37 of his book on bicycle wheel stiffness should leave some of you with something basic to think about.

"Stiffness, in its various forms, is a subject often discussed by bicyclists with a regard to components as well as frames. Stiff wheels are often mentioned with approval. However, it should be noted that a bicycle wheel is so rigid that its elasticity is not discernible because the tires, handlebar, stem, frame and saddle have a much greater combined elasticity. Therefore, the differences between well constructed wheels are imperceptible to a rider. The "liveliness" attributed to "stiff" wheels is an acoustic phenomenon caused largely by lightweight tires at high pressure and tight spokes with a high resonant frequency. This mechanical resonance can be heard, and possibly felt in the handlebars, but it is not related to the wheel stiffness.

Stiffness is a measure of how hard it is to deflect the wheel, or more precisely, the ratio of load to displacement. Stiffness is not strength. For example, Plaster of Paris is stiff, but not very strong. Since wheel stiffness is so often discussed, the various aspects of stiffness are treated here in more detail than they deserve. Wheel strength, and not stiffness, is the important consideration. If the wheel is strong enough for its intended use, then it is more than adequately stiff.

The terms "stiffness" and "rigidity" are often used when people talk about bicycles. Unless these terms are defined, they are just as vague as the even more popular catchall term "responsiveness". These technical-sounding words can be misleading. Stiffness alone is not the ultimate measure of a good wheel, but rather the balance of stiffness and strength that enables it to carry loads and withstand shocks. "

CONNECTED READINGS :

Jobst Brandt : Part I
Jobst Brandt : Part II
Jobst Brandt : Part III
Jobst Brandt : Part IV
Jobst Brandt : Part V

* * *

27 Jobst Brandt : Part IV

Continued from Part III.

Thank you for patiently waiting to read Part IV of this exciting and important interview. In this installment, I asked Jobst to tell us more about his career path at Porsche and Avocet. The discussion then flows into his unique bicycling interests. Why does Jobst have only one bike? Why doesn't he believe in cycling races? What does he love best about Europe? You have lots of material to read below!


17. We discussed your engineering career in brief but a complaint was that I didn't burrow into specifics. Firstly, my readers and I are very interested in knowing how you landed a job at Porsche. Could you please elaborate on the nature of the work you had there?

JB : Sure. I was stationed in Germany (Aschaffenburg) near Frankfurt in the US Army Corps of Engineers and wanted to buy a car because all I had was my bicycle as transportation. I found that I could buy a 356 Porsche at a reasonable price and did so. In that pursuit I reviewed the owner's manual and was told most of it came out of the factory shop manual, that I also examined.

The translation from German to English was poor and in some places incorrect so I dropped in on the Porsche plant in Stuttgart-Zuffenhausen after I got out of the Army and was on my way south to visit my bicycling friends in Florence. I proposed to their personnel manager that I go to work there and with my knowledge of German and English along with my facility with automobile jargon in English, I could do the manual a service.

I was hired to come to work in the fall and did a good job in translation, a version that was recognized as better than what they had. When that job was done, I asked to be transferred to engineering and was assigned to the chassis, brakes and steering division. When I got there, the project leader felt he had too many people and transferred me to Special Products (the racing department) that was just being started.

As I started design work, more and more of the car was transferred to my drafting board and I did the layouts for the chassis, wheel suspension, brakes, steering and transmission. I got along fine in that team and stayed with it until the car won the Belgian GP and Mr. Porsche said it was too expensive. So when he had achieved what he wanted, that racing department was dissolved. I transferred back to the production car division and designed the steering and front suspension.


18. Looking back at Porsche now, what lessons did you learn? Would you drive a Porsche if you had the money to afford one?

JB : From my work there, I discovered why one should not build rear engined cars, air cooled engines and torsion bar suspensions. That Porsche persisted in that design was unfortunate and you see they gave up on air cooling when it died everywhere else in the industry. I wrote for Wikipedia why we ever had air cooled engines in the first place but the Porsche faithful deleted most of that essay, as you can read at Wiki. The "Why" part of that thread is slightly what I wrote but has been diluted.


19. Interesting! So again, would you buy a Porsche or not? How about a Porsche instead of a bicycle? That's a trick question.

JB : Today's Porsche is more a show piece with allusions to great handling and power, but it remains only a symbol with little practical value, much like a Corvette. These cars are mainly image with little real significance.

Ever since returning the the US from Germany, I have driven one make of a station wagon or another. They have served me well and I have transported many bicycles to interesting ride locations. I don't think you can make a real parallel of driving a car and riding a bicycle.


20. Porsche was one of the many places you worked at. You also worked for Avocet. I understand you were a tire designer, is that correct? How did your hand play a role in better designs there?

JB : When the Hoffacker brothers started Avocet, I came up with the name and the logo, which I had as my linoleum block Christmas card for 1973. I've carved a linoleum block for many years, something I learned from my father. The subjects are many - birds, machinery (RR locos), the Locher dual side engagement cog wheel and the Stelvio National Parks logo.

I saw Avocet as a way of getting some bicycle features I couldn't get elsewhere. The Altimeter was an important one for me because it's logic has a good patent that is essential to accumulate climb, something others with altimeters cannot do correctly because they have no hysteresis that ignores small dips in roads or barometric fluctuations. I suspect most of them are not aware of these problems and never think of adopting that patented concept. It took me a while to explain it to Avocet engineers making the hardware and software.

I also wanted slicks, recalling how well our Clement tubulars cornered on wet and dry without miniature car treads that do nothing. Avocet recognized the advantage and made the best slicks ever. To assure riders that one can corner on them, I had a picture taken with me cornering hard. They also had the lowest rolling resistance when they were built by IRC. IRC no longer makes bicycle tires.

Photo showing Jobst Brandt testing a pair of Avocet tires.

21. Let's talk bicycles. You've often been photographed with a tall and yellow steel bike. Infact, I have not seen any other bikes associated with you. Would you tell us more about it?

JB : When my Cinelli got old and developed cracks from riding Campagnolo Record hubs with a long overhung axle on the right end, my good friend and great riding companion Peter Johnson built me a new frame. Earlier, Tom Ritchey had built me a bicycle that I had wrecked by descending into a cross-drain on a forest descent, so Peter built the bicycle you see in photographs. It has an oversized downtube and is fillet brazed. It needs a paint job now that it is about 20 years old.

The reason for yellow is that cracks can be seen better than on most other colors than white. I realized that getting rid of the crack generators was better than a good color. That's why I am riding Shimano 7-speed hubs that have no axle overhang as Campagnolo hubs. Peter also built me a new fork with a threadless steer tube for which Ritchey gave me the stem.


21. So you have no other bikes apart from the yellow one?

JB : No. I never had more then one bicycle mainly because I maintain it and can ride only one. That's my main problem with the bicycle faithful. They collect these religious symbols and treat them as near human icons.


22. Typically, how much would you ride your bike in a year when you were young?

JB : I have always ridden about 10,000 miles per year and probably still do, now that I am retired. That comes to about 200+ miles per week. After a recent car incident that caused a couple of broken ribs, followed by much rain (daily) I missed about four weeks of riding and am getting back in shape now. That isn't easy for an old man.


23. I'm sorry about the accident but for a person of your cycling calibre, you should be able to ease into cycling without problems.

JB : I don't recall winters being so wet and cold but that slows me down these days.


24. As a well-respected engineer and cycling enthusiast, what do you think of UCI's decisions to ban certain bike designs? Do you think its healthy for the sport or are you one who supports tradition?

JB : That is a mis-characterization of racing rules. The rules are there to attempt to make a "level playing field", not to prevent technical advances. The HPVA is there for innovative two wheel designs, most of which violate the concept of preventing mechanical advantage to win in competition rather than by athletic ability. As I mentioned, I was aware of that in my younger days when I was faster than all others on the road through ability rather than a special bicycle.

I don't support tradition, in the sense of freezing technical advances to an older time. I think advancements can be made but not in "space age" technology for bicycles.


25. Do you believe that bicycle design has reached a state of saturation, if you will allow me to use that word? If not, where could some more genuine improvements be made according to you?

JB : It is not bicycle (technical) but rather in styling design where the effort lies. Saturation only appears to those who don't understand what the problems are. Classically, the threadless steertube was a great leap forward and has not been accepted as such by most of the contributors to rec.bike.tech. There is where saturation lies.


26. Do you have time to follow cycling races and all the doping drama? Do you have any opinions on Lance Armstrong's uncertain comeback, or on the talented Alberto Contador?

JB : I don't like professional sports and don't follow them, other than having seen the GdI or TdF on my bicycle trips in the Alps. That goes for team sports, skiing, and other "my aerobic abilities are greater than yours" type competition. No one benefits from that in contrast to demonstrations of skill as in music, painting, sculpture, and ballet. Art is full of pleasant venues. This other stuff is just a bunch of gladiators. Just look at the bodies of US football players.


27. Did you race back in the day? Were there any wins or accolades?

JB : Only a couple of time trials. I decided that massed start races were full of hazards and some trickery. I only raced a couple of times before I decided to concentrate on touring.

Dated photo showing Jobst standing proudly with his friend at the peak of the Penserjoch. This is a 1950 m foot climb near the Italian-Austrian border.

28. Touring is one what I wanted to concentrate this discussion on. Your Alpine tours are stuff of legend. I spend some time reading your colorful tour reports and loved the prose. It seems to me you have made an enjoyable annual tradition out of this. What got you interested in the Alps from a cycling standpoint?

JB : My father was a tourist as I am and though he did his trips by car with the family, it was not planned with motel reservations but rather "eine fahrt ins Blaue" as it is called in German - "a trip into the wild blue yonder". When he took his appointment to Gen. Lucius Clay to go to Heidelberg, the US economic headquarters, he put us up in civilized central Switzerland and so doing took us on a car trips over the old and famous mountain passes. I recall these times as a high school youngster vividly as does my older brother. Of course I wanted to see those places again and doing so on a bicycle was a better experience.


29. If you don't mind, tell us about your favorite spots out there?

JB : Pleasant hotels in villages or even solo in the mountains are common in Europe, something that makes it more pleasant. Also, these are family operations with no motel chain in the background. We have similar places in the Sierra and so we choose to stay there.

A photo from 2006 showing Jobst Brandt with his friend at the Iseran Pass in Savoie, France.

30. Have you openly supported bicycling advocacy? Also, what message do you have for those folks who desire to adopt bicycling as a mode of transport?

JB : I think my advocacy should be evident from my ride reports. These reports are not filled with arduous hardships and suffering, but rather the beauty of the places and people I encounter. I think that is what life is about and many people have followed these trips. As I ride here and in the Alps, I am often greeted by name from people I don't know. I find personal notes taped to the poster of me at the cliff in the Refugio Bonetta.

Don't cycle unless you are a good physical specimen, otherwise its a drag and no fun. Also, get off the million dollar non steel bicycle.


Part V to come soon...

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I mentioned in the interview that I enjoyed the colorful prose in some sections of Jobst's ride reports. Here's an example I wanted to share with you, sourced from his 2006 journey :

Friday, 14 July (Samedan - Borgomanero, 222km, 1200m)

"We pushed off into a cool sunrise, choosing the urban route through Celerina and St. Moritz (1837m) to get a closeup view of the ritzy hotels, so called after hotelier César Ritz (1850-1918) who invented the genre in Paris. Among other things, we passed the giant aerial tram, the Signalbahn, that connects downtown with ski and hiking area toward Piz Nair (3056m).

Riding west along Lake Silvaplana, past Silvaplana (1815m), at the north ramp of the Julier Pass, the scene was right out of a tourist calendar. Farther on, we rode along the Silsersee, the source of the Inn River, to reach the one sided Maloja Pass (1815m). From here a curvy zigzag but brisk descent took us down the wall of the box canyon to the flat valley above Casaccia (1458m) and on down the valley toward the Italian border at Castasegna and finally Chiavenna (325m).

We crossed the Mera River to ride along the west side of Lago di Como to appreciate the many unbelievably ornate villas with manicured gardens surrounded by stone walls, fences of fancy ironwork, and neatly trimmed hedges. Sail- and motorboats were sailing on the lake and once in a while a ferry/cruise boat plied its course between the major towns around the lake.

Before I realized it, we had passed through Menaggio where I had planned to turn west to Lago di Lugano to view more villas, but we were doing all right here and continued to the outskirts of Como where we took secondary roads south of Varese to Borgomanero (538m). We found a wonderful hotel with a garden dining atrium at the end of a long cul-de-sac off the busy main street.

We parked our bicycles in the garage and got cleaned up to appear for dinner in our travel finery to enjoy a delicious Italian dinner on this comfortably warm summer evening. During dinner, alpine swifts darted overhead, picking off insects while giving their characteristic modulated chirp as they worked until dusk. After that, bats took over the task. "

CONNECTED READINGS :

Jobst Brandt : Part I
Jobst Brandt : Part II
Jobst Brandt : Part III
Jobst Brandt : Part IV
Jobst Brandt : Part V

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18 Jobst Brandt : Part III

Continued from Part II

In this section, I press Jobst to talk about his online persona. People have mixed feelings about him. One side has it that he's an interesting person with an immense wealth of knowledge and experience. Another side is always wary of his crusty, irritable personality which they feel can be off-putting and hard to work with. What does he feel about all that? Well, find out.


11. There's the real Jobst Brandt, and then there's the online Jobst Brandt. The latter portion in your claim to fame seals your status as a no-questions-asked guru of bicycling, if you will. I was interested in knowing where all this began. Did someone invite you to compile these words of wisdom and archive them online or was it self-started?

JB : I started writing them long ago to fill voids in mechanical understanding that I perceived. Becoming a guru was from the attacks that responded to my explanations of natural phenomena. The impression probably comes mainly from bikers who believe in their "common knowledge", that is mostly misdirected. They feel they need to defend that position and go on the attack. Just search how many so called engineers insist that my analysis and instructions on the bicycle wheel are all wrong. I'm used to that. It's the story of my engineering career. I hear similar stories from other engineers.

For years, there was just one newsgroup before splitting up into tech, misc, rides, market, etc... Back before it grew out of its pants it was a pleasant place with only rare disagreements. Once the place became noted, the BS artists realized they had a rostrum from which to spread their religion.


12. You also have an almost cruel stance against irrational statements. You are popularly associated with this wise, very experienced man with meticulous attention to detail, but also moody and cranky and perhaps a little myopic to suggestions while sticking to old fashioned advice. Do you agree with some of these views?

JB : I have little patience with people who write anonymously, mainly because their reason (incompetence) for doing so. Well they don't explain why it is "old-fashioned" advice. Much of that comes indirectly from my bicycling that is not racing. That Sierra ride that is on someone's web site is a classic for iconoclasts.

They feel that I am not giving them their due when in fact I don't mention their style that they are trying to claim is the only way. Another earlier point is that I was a faster and stronger rider than most of the locals and that irritated newbies. I am old and slow now but still go on long rides.


13. Coming back to this idea of people having misdirected knowledge, what's your pick for one that you find having to straighten out often?

JB : A classic is that a hub of a bicycle wheel "hangs from the top spokes". That struck me when I first got a high class Cinelli bicycle. I realized that this ignores pre-stressed structures and that most people wouldn't recognize a pre-stressed structure if they ran into it. I once took a train to Budapest solely to see the worlds first significant suspension bridge, the "Chain Bridge":

This bridge was built without suspension cables that Roebling had not yet invented, so all elements were long steel pinned bars. Click on center picture second row and see some of the beautiful structures engineers have built. The last shot in that sequence is the Chain Bridge. I was not disappointed.


14. I'm curious - do you personally know any of these online folks you exchange all this information with?

JB : A few who are pleasant, yes. That's where I found the German (Klaus Schmidt) who assisted me in proof reading the German translation of my book. He once wrote off and on to rec.bicycle, but when it got big and broad and rude, he bailed out. The same seems to have happened to Bruce Hildenbrand whom I mention in one tour report.


15. Which brings me to probably one of most important questions to wrap up. How well did you know Sheldon Brown and could you write a little about your relationship with him?

JB : I got along fine with him and we talked at InterBike for a few years until he said he was coming out my way in the summer to visit his daughter Tova, who was attending UC Santa Cruz. I met him at his motel in Santa Cruz, 65 miles from my house, from which we took a great ride along the coast and up through big redwoods before he descended to Santa Cruz from Summit Road while I rode home. He took the FAQ title page picture of me standing over my bicycle on that ride and I took some good ones of him that I am sure his wife has suitably saved.

Jobst Brandt and Sheldon Brown in Santa Cruz in 2006. This photo was borrowed from the latter's journal, where he had documented the day's ride with Jobst.

16. He was a renaissance man. Do you feel the cycling world is a little emptier without his presence of mind?

JB : I liked him a lot and found him to be no mechanical dummy. As you may recall, The London Times wrote a glowing obituary after his sudden death that came after the second time he came to Santa Cruz on which he and his wife had a lovely ride around the place. He was already suffering from deterioration but didn't let it take his bicycling away. The next time I saw him he was on an electric three-wheeler at InterBike, no longer able to walk. A great man! As you see, he believed in the stuff I wrote and put it on his web site.


Part IV continued...

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Here, I have dug up two relevant snippets. They contain Jobst's replies to newsgroups folks. In one, he clarifies the loads on the bicycle wheel that appeared difficult to grasp for one gentleman. In the other, he admonishes someone for posting anonymously. Be warned! Never post anonymously if you are writing to Jobst. And while you're at it, avoid smileys and other nonsensical characters too!

Topic : Bicycle Wheel Loading (1999) : Eric Salathe initially wrote : "The Bicycle Wheel is beautifully written, but the persistent lack of acceptance of this idea among its readers, as well documented on this list, shows that the 'wheel stands on its lower spokes' slogan does not accomplish its function."

JB's reply : "I chose not to condescend and state anything other than what is engineering fact, explaining why and how the wheel works. I know that many people have great difficulty visualizing this and I believe that is why the wire spoked wheel remained misunderstood and not analyzed until "the Bicycle Wheel" was published. Previously many authors wrote extensively about what they believed took place. None of these recognized that the top spokes or, for that matter, any other spokes of the wheel were affected by the vertical load except the bottom few in the tire contact zone. That loads only unload spokes was also not understood. When a wheel is overloaded or crashed to destruction, none of its spokes are overloaded (other than possibly being kinked after becoming slack).

I am fairly sure that the whole subject is still a mystery to most people who should understand it. I overhear conversations and see postings here that reveal these misconceptions. Even people who seem to grasp the concept have said as much as "I crashed my wheel and have to get all new spokes". Progress is slow in coming."

Topic : Anonymous Postings (2009) : "Dan O" initially justified to Jobst the unseen value in anonymous postings by writing : "What's in a name? You must assume that any information you make available on the internet will be harvested, stored, and used indefinitely and completely outside your control. This information can be accessible to any and every wacko 'in the world'. The availability of information can even affect the security of other people who might never have chosen to make it publicly available. So it is a sensible basic tenet to not provide unnecessary information to systems outside your own control."

JB's reply : "I suppose you don't take off your dark glasses when introduced to people with whom you exchange thoughts and ideas. That and chewing gum is something one once learned not to do in polite societal encounters. I realize that this forum lost all that about 15 years ago and now we occasionally read about newsgroups that have vanished for the large volume of rude and anonymous postings.

I hope you noticed that the least civil postings come from a raft of secret agents. Even Sheldon Brown had no effect on the genre in his days in spite of his courteous style of asking these writers to sign their work with real names. I guess this is like many other fads that people follow without cause or reason, like wearing dark glasses in all weather and night time too to have the I-spy look."

CONNECTED READINGS :

Jobst Brandt : Part I
Jobst Brandt : Part II
Jobst Brandt : Part III
Jobst Brandt : Part IV
Jobst Brandt : Part V

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3 Jobst Brandt : Part II

Continued from Part 1.

Thus began the interview with Jobst Brandt. Note that each of these 'sessions' are appended with some of his interesting writings that I found on the web. I have chosen them carefully not only to stay with the topic, but also to bring to light Brandt's wavelength of thinking that is very unique to him.

Pictures : Standford University. Source.

1. We mostly know the man Jobst Brandt through online articles and a book, but what are the missing links in the story? Firstly, where were you born and was the bicycle a constant in your upbringing?

JB : I was born in NY and moved to Palo Alto in 1938 when my father took a position at Stanford University. I have a BS in Engineering from the same. I started bicycling at age five and found it useful to go to school and to the community center and swimming pool that was more than a mile away. We even did outings to the yacht harbor, five miles away. I was gifted with big lungs and strong legs and so I enjoyed it.


2. What did you like about mechanical engineering that made you pursue it? Did you always feel math and science was your forte?

JB : I suppose one is born with a preference for music, sculpture, or science in various forms. At preschool age I was always interested in how things worked... mechanically and otherwise. Electronics was not one of them.


3. What were some of the most memorable things you did in your engineering classes at Stanford? Were you involved in extra-curricular activities and such outside classes?

JB : Not much, my interests were in practical things. Railroads and steam engines were a large attraction for their mechanisms and how they worked. The same went for cars that needed much mechanical assistance in my youth.


4. I see. So tell me where this passion for the physics, mechanics and failure of bicycle parts come from anyway?

JB : These are standard failure mechanisms of machinery that I watched with interest starting in my mother's kitchen and our cars and bicycles.


5. Do correct me if I'm off a bit here in reading you. Would you consider yourself frugal? Did you parents ever bring you up this way, cultivating in you the need to be conservative with finances or was it the engineering career that taught you that money and resources are limited, hence design must be based around that.

JB : I think you are jumping to conclusions. As a youth I lived through the days of the second World War in which many things were scarce (due to the "War Effort") so we were careful about what was thrown away or repaired. I don't see a great frugality in my habits, I think they are more in line with not being a conspicuous consumer. I know many bicycle riders who are embarrassed to patch a tire tube because they don't want to be seen as poor people or cheapskates.


6. Have you ever considered teaching?

JB : Yes and no. I seldom have time to develop a routine. Guest speaker is a better venue.


7. Would you kindly share a little about your professional background for my readers? I've read that you've had a stint at some big names such as Porsche, Stanford Linear Accelerator Center, HP, Avocet etc? How do you explain a famous bicycling personality working in all kinds of places, from premium sports car company to computers to particle physics before jumping into the bicycle industry? I mean, you must have picked up on a considerable wealth of knowledge from all these experiences.

JB : I think you confuse bicycle technology with general engineering problems. Be that a cogwheel mountain railway or a sewing machine, failure occurs for the same reason, that of misunderstanding of the mechanical demands by the designer. My work at SLAC introduced me to computing and enabled me to develop cam shaft design programs as well as graphic display software that most people at SLAC and HP used.

The wheel drawings in my book were drawn with my own software and along with that, I wrote the finite element program to analyze wheel deflections and spoke elongations. That program came from a pressure vessel analysis one of my colleagues wrote for his masters thesis at California Polytechnic State University, San Luis Obispo.


8. Remarkable! You're probably more than qualified to put forth an opinion here. As an engineer, what do you feel about the state of engineering these days? How do you compare engineered designs now to those in your times?

JB : I believe it has always been poor in most places with singular exceptions, and those names certain engineers don't forget... like Leonardo, Tesla, and van der Waals, whose work is mainly misunderstood. Some people have heard of van der Waals forces but that's all. It involves, among other things, adhesives that are a mystery to most technical people. This gets close to tire patching and why patches won't stick.


9. Do you have any examples of poor engineering in our current atmosphere?

JB : Toyota is a good example of bad technical management. Managers who manage technical people must understand the technology they expect from their people. Many of my managers recognized my understanding of machinery and assigned complex problems to me that others in the group did not master, be that in the US Army Corps of Engineers (weapons assembly, demolitions and bridge building), Porsche, SLAC, HP Frequency and time (Interferometers and optics), opto-isolators or memory disk friction and other mechanical problems.

Those Toyota cars should never have gotten this far if the designs were reasonably reviewed and subjected to proper road tests. They weren't, probably under the belief that competitors were not operating any differently. This is a top management failure that reaches down to the lowest levels.

I am dismayed at the press analysis of the whole affair, instead of recognizing it as bad technical management. Having seen such design problems I think I have a feeling for this.


10. To wrap up this session...you're probably retired now, is that correct? What do you do these days?

JB : The work at HP ended and did not get renewed so I am on vacation full time. I ride the bike when I can and see how my friends are doing. I live alone and my sons live nearby, but even closer is my former wife. One of my brothers lives in London and keeps in touch by email.


Part III is continued...

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Jobst Brandt wrote the following in 2004 to the topic 'Learning To Ride A Bicycle'.

"It seems to me children who don't easily learn to ride a bicycle may not be inspired by other children "on the block" who have already achieved this mobility and may not have seen their parents ride. My experience, both as a child watching siblings learn to ride in a single session, and as an adult doing the same with my children, makes me think that this is the case.

Training wheels make an unstable tricycle of a bicycle, tricycles having been banished from our toy repertory for falling over when ridden too fast in curves. The method most commonly used by successful teachers is to hold onto the saddle such that the child cannot tell whether the parent is still holding on, or at least has the hand where it could help in the event of instability, while pedaling along.

I have not seen this method fail with normal athletically inclined children in the 4-5 year old range. It seldom takes more than one session to get the child riding solo. Of course there must be a trusting child-parent relationship for the child to believe this is a reasonable endeavor."

CONNECTED READINGS :

Jobst Brandt : Part I
Jobst Brandt : Part II
Jobst Brandt : Part III
Jobst Brandt : Part IV
Jobst Brandt : Part V

* * *

13 Jobst Brandt : Part I

This interview has also been shifted to my new blog where you can read the entire piece in one spread. Please visit this link. 

Jobst Brandt during his traditional tour of the Alps in 2008. Image Courtesy : Source

If you will forgive my black and white comparison, there exists two categories of people - the purists and the pragmatists.

Purists go strictly by the book. They are conservative about new methods and much comfortable in being a step back from the rest, never wavering from first principles. Pragmatists do what is necessary to be practical and are ready to push the boundaries into new knowledge. They follow experimental evidence, rather than strictly following someone's theories as to why the world behaves the way it does.

I'd like to think a good bit of both is needed when one is an engineer. Not only do you have to be conservative with designs that are stable and cost effective but you must also be results oriented and ready to accept or apply something new if that's what a correct interpretation of data reveals.

I must admit it was a bit difficult for me to wonder where I'd place Jobst Brandt, a Stanford alumni and legendary author of The Bicycle Wheel. This work is widely regarded as the bible of wheel building.

For starters, Jobst is a resident of Palo Alto in California. While he is a graduate of a reputed institution and an acclaimed author, his experience is also quite rich through an engineering career that spanned from Porche automobiles, Stanford Linear Accelerator Center and Hewlett-Packard to Avocet bicycle products. For others, he is a person of many words, opinions and very colorful Apline cycling memories. Perhaps nothing may be more famous about him than his myth busting advices and recommendations on everything cycling.

Getting back to my point earlier, reading this book entertained in me the notion of Brandt being the quintessential engineer, you know, the idea I talked about earlier. Guided by both theory and observation of failure rates, Brandt documented in simple English how to build the most durable wheels at one's leisure.

A highlight in this work was in how he managed to convince readers that the bicycle wheel is an unusual structure that beat intuition, hence conventional wisdom and folklore would not work in understanding it. It was the precise scientific method with which he approached the subject that was most fascinating to read.

But even three editions later, as reviewers say, the book didn't expanded itself to absorb the current advancements in wheel building. The book didn't explore new methods in finite element analysis in novel low spoke count designs, came the complaint.

Then there were others who remarked that the book was the work of an opinionated pedant, a cranky Luddite, a hard headed, pompous individual resistant to change. That the book didn't correct erroneous statements, graphs, calculations and so on and so forth.

Brandt himself has not shied away from his critics, some of them engineers, and has been fighting back with nothing less than outspoken defense. When asked about this, his understatement would be that he is used to this. Yet, you get a sense that there's frustration somewhere when he admits it is the highlighting story of his engineering career.

I suppose it is easy for someone to be enveloped in other people's criticism of Brandt and his ideas. But it was hard for me to read him as I have not known him personally.

A few weeks back, it dawned upon me that I must engage in learning where Jobst Brandt and the geography of his ideas and opinions sprout from. I thought that might be a rewarding experience and it was to a degree, as he was very forthcoming in reply to my barrage of questions. The secondary objective of this exercise was to have the enigma of Jobst Brandt as a person stripped away and have this brought to the readers of this blog.

A dated image showing Jobst Brandt navigating unpaved sections on the Gavia Pass

This week, I will present to you the conversation I had with the interesting and sophisticated personality that is Jobst Brandt. Topics range from his personal life, his professional career, his cycling achievements and some of his steadfast opinions on engineering and the state of cycling today.

CONNECTED READINGS :

Jobst Brandt : Part I
Jobst Brandt : Part II
Jobst Brandt : Part III
Jobst Brandt : Part IV
Jobst Brandt : Part V

OTHER INTERVIEWS :

Conversations With David Gordon Wilson (Author of Bicycling Science)

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