11 52x12 vs 52x11 Gearing : A Look At Chordal Action

If you're the type who likes to gun it down the line in high gears, you may have wondered more than once - what is really better in terms of crankset chainring-rear sprocket size, would it be a 52T x 11T or a 52T x 12T?

At the same RPM, you get a slightly higher top end speed with the 11T at the sacrifice of some torque. But if you're asking this from an efficiency standpoint (ratio of input power over output power), its a slightly tougher nut to crack if you don't have actual measuring equipment.

I won't talk directly about efficiency but I'll talk about something else that you may want to start connecting, perhaps more with equipment durability than efficiency.

A bicycle chain has links, connected by a distance called pitch which is usually 1/2 inch in bicycles. When you're riding your bike at a cadence of 100 RPM, the chain has an average velocity called pitchline velocity. At the sprocket though, some interesting things happen with chain velocity.

For one link in your chain to engage a teeth in your sprocket, the link has to swing about an angle before the roller is seated between tooth. This is called Angle of Articulation, calculated by using the relation : 180/T, where T is the tooth count of the sprocket.


For a 11 tooth sprocket, the angle of articulation is 16.36 degrees, while for a 12 tooth sprocket, it is 15 degrees, a reduction of 8.3%.

Because the chain is turning at these sharp angles at the same time impacting the teeth, the velocity of the chain is not constant, but infact fluctuates between the maximum and a minimum each cycle. The maximum occurs before engagement, the minimum occurs after the link has swung in engagement. This change in velocity is called Chordal Action.

The point is that chordal action results in fluctuations in chain transmission and may be minimized by reducing the angle of articulation, which decreases with increasing sprocket size. For 11T and 12T sprockets, which are about the smallest standard sizes you can find in the bicycles, the angles are tight which results in uneven exit velocities.

But is it something you should worry about? The math is complicated to present here so I just did all the calculations myself elsewhere to look at chordal action. Perhaps you can decide whether it matters or not after looking at the following theoretical numbers.

Say you're riding hard at a cadence of 100 RPM with a 52 front chainring. The RPM at the rear sprocket is multiplied by the gear ratio, which results in 433 RPM with 12 T and 482 RPM 473 RPM with 11 T. With a 12T sprocket, one cycle of tooth engagement sees a 3.4% variation of chain linear speed, whereas an 11T sprocket sees 4.1% change in linear speed for the same because of the tighter angle the link has to swing.

Here are two graphs I generated :

Note : Chain velocity is a function of pitch circle diameter, RPM and articulation angle

What this does for transmission efficiency in bicycling is moot. What I wanted to present before you is the fact that chordal action is real in small sprocket sizes, and it has an effect on your tooth wear and pulsating motions at high RPMs. But it may not matter in low cadence (60 and below) and if you're using wear resistant, hardened sprockets. Feel free to discuss.



ADDITIONAL RESOURCES :

Dan Connelly : Drivetrain Losses

* * *

7 Saturday Stupidity IX

While the geopolitical problems in the middle east continues on, another conflict moves on unabashed through the years.




We wish both riders good luck in their senile competition. Love him or hate him, Armstrong is doing will do plenty for Acne.



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

* * *

24 Kolelinia : Engineering A High Flying Bicycle Lane

Bulgarian architect Martin Angelov has a simple game plan to beat cyclists' urban commuting woes. Take the bike path above to the skies, well, to a maximum of 15 ft over the road to be precise.

Wait, what did you say? That's right. Enter the Kolelinia, an interesting transportation concept that actually won The City Transportation Interchange Brief in London last year after Martin submitted a pencil sketch proposal to them.

What is proposed by Martin is a bicycle lane made of steel wire - static in all respects - unlike a ski-lift which would need electricity. Now don't equate that to cycling on a literal wire. Actually, the proposal is for an elastic furrow, made from rubber, supported by two steel wires and about 12 inches in width. A third steel wire is for safety. The bicycle's wheels will ride in this furrow.


The idea also proposes a handlebar mounted pulley system that attaches to the guide wire so that the motion of the cyclist is constrained along the furrow (and not onto the road!).

What will the bicyclist have to carry with them in order to use this system? Two things : A safety harness and this pulley thing (or "personal safety device"), both of which can be carried in a backpack prior to "boarding" the sky lane, according to Martin.


The reasons for proposing this bizarre, but unique idea are, in Martin's own words to me, the following :

"I want to achieve a complete independence between the car and bike stream in the zones where they intersect each other.

Kolelinia generates additional space in places where there is no room for bicycle-lanes.

I want to prove that it is possible to move on a higher level (4,5m max) with a minimum of resources on a weightless network. Of course, absolute safety comes first.

Last but not the least, I would just like to provoke people to look at transportation from another point of view, just like the sci-fi movies make us dream!"

I'm not sure whether it was a sci-fi movie that came to my mind first when I saw the drawing plans for this idea on his website. I think what came to mind instead was the suspended walkways failure at Hyatt Regency in Kansas (1981) that killed 114 people in one shot.

I translated that fear to Martin, asking him whether he's got his engineering calculations right for the structure he's proposing. I also asked him who he plans on giving this ultimately as a contract to. The reply was not surprising, because the idea does seem to be in its early conceptual stages.

So what is the future of this concept and how does it go from concept to prototype to realization? Will it see the light of day in the litigious environment most we us live in?

Here's Martin's reply :

"I have to mention that the idea has to evolve naturally. Nobody will build such a network without a real need. But first we have to demonstrate that this system works in the real life. For that reason we have to follow some steps :

First, I have to make a team for realizing a basic hand-made prototype of the concept (10-15m long). Only this prototype will show us the real problems with the design.

Second, after we have already dealt with all the issues, we have to build something bigger, let's say something for entertainment. A short touristic line in the city or an extreme line somewhere in the nature or a whole mountain-bike trail, for those who are looking for adrenaline.

If all prove that it is safe, the system will find its place for mass use naturally. Nobody will make you use it if you don't want to.

I'm working on the first step now and I'll cover each step on my website. In addition I'm working on a completely new concept, but it is early to talk about it."

Here's one personal thought to Martin. If you happen to visit a bustling city like Dubai, where traffic congestion is at its height, transportation planners have realized simple methods to help people get across huge highways. One is in the picture on the left. To use this, all you need to do is mount a pair of steps or ride an elevator and then walk, or ride your bike on this overpass. No need of cables, harnesses and things of that nature.

What's nice about it is that it is enclosed so you're protected from the elements. The biggest advantage is that it can be used not just by cyclists, but by any individual, just like actual bike paths.

I don't see it as an easy task, this idea of spending public money to provide just cyclists with their own little fancy skylane. Not to discourage you. It's a nice idea but I don't see this finding favor with development authorities easily.

What do you readers have to say?

ADDITIONAL READING :

Kolelinia Concept's Official Website
Design Case-study : Pedal Powered Canyon Transporter

* * *

20 Practicalities Concerning The Copenhagen Wheel

Good morning!

For lack of a super-stimulating post today, I thought I'd immerse myself a bit in the hype surrounding the Copenhagen Wheel before the subject becomes rusty and unwrap this pretty looking present.

So I'm taking it for granted that you folks will have some prior knowledge of this new hybrid e-bike introduced by MIT's Senseable City Lab.

Well, the folks are not actually marketing a bike technically.

They actually demoed a hub-motored wheel during the Climate Summit in December that you can shift around and adapt to different bikes for "city riding", the idea being that it stores energy through regenerative rear wheel braking action and gives it back to the rider when they need a 'boost'. It is sort of a leaner, maybe meaner version of the gas powered Revopower idea that never took shape. Remember that?

An attractive proposition is that this wheel can be monitored by a smart phone via blue tooth and all the electro-mechanical aspects are packaged into one assembly - the wheel itself. And then it measures environmental variables like noise, pollution and so on and throws all that data into your phone for your city riding pleasure.

It is by all means an academic project, funded by the city of Copenhagen, Ducati Energia and the Italian Ministry for the Environment.

Now when I hear of projects like these, I switch off the ads and start looking into specifics. I thought for an institution like MIT, you would expect to see some numbers posted on their website at the least, or a whitepaper indicating weight, wattage requirements, cost, efficiency etc. I certainly haven't found much other than a Java based applet you can sort of play around with.

So here are my questions & concerns for the boys and girls at MIT, which I think I sounded off a month back to Bicycle Design.

What is the energy content of the battery (Wh/kg) and energy use per distance (Wh/km) of this product? Multiplying both will give us an estimate of distance/kg of battery weight and total energy capacity per charge. Knowing cost of electricity, someone can easily calculate the true cost of riding the bike or a bike equipped with the wheel and then compare it with with a bike not equipped with it.

Then comes the question of braking energy recovery. How many stops would a cyclist have to make to recover at least 10% of the total battery capacity back and by how much will their range be extended?

Let me give you a perspective. A 180 lb man with a 20 lb bike traveling at 15 mph has 2026 joules or 0.56 Wh of kinetic energy to shed, in order to come to a stop. Note : These are back of the envelope calculations I just roughly did.

So, with what efficiency will the recovery system be able to capture some of that? 70%? 80%? Let's assume 75% which is a reasonable number. With that, I can get back 0.42 Wh or 1516 joules back, but I can only put this energy back into the battery at a certain charge rate which really depends on the battery's specs.

So for illustration, if battery's max charge rate is 100 joules/sec, 1516 joules will take 15 seconds or more to put back in.

Now realistically, no one takes that long to stop, even though the US CPSC recommends that brakes should stop a cyclist in 15 seconds from 15 to 0 mph.

So realistically, let's say people take about 3-4 seconds every time to stop. Using the 100 J/s charge rate, cyclist can only put in 400 Joules or 0.11 Wh back every stop. So the question again becomes, how many times does a cyclist have to stop to put back 10% of kinetic energy of braking, at 75% efficiency to get the extra amount of miles, given the limitations of the battery?

If its a reasonably good amount, it may make some sense in a crowded urban area like Copenhagen, otherwise not really considering buying costs and life cycle costs. Again, only the average numbers over long riding in the city will give you any solid perspective on the practicality.

In short, without specifics like what I'm calling for, no one should start rooting for this product as a game changer just yet, for that is just silly in my book - a case of inflated yet unwarranted attention that a lot of blog fodder command these days.

Sometime back, I noted that the city of Copenhagen is en route (forgive the pun) to "biking superhighways". With that kind of a future for this city, I expect some of the stopping usually encountered in tight city riding conditions to reduce. So then the question is, will the Copenhagen Wheel even be deemed necessary then?

As usual, I ask too many bothersome but nevertheless important questions. The answers are reluctant to arrive. Or it just might. Right MIT? :)

ADDITIONAL READING :

MIT Press Release : MIT's Big Wheel In Copenhagen
The Revopower Puzzle : Where Is It?

* * *

19 Look Ergopost Seatpost Failure

When you buy a $250 product, nothing in that price tells you that it will last. This is a fallacy bike consumers often go through in their minds. Is high price = safety & quality? Not necessarily.

This $250 "Ergopost 4" didn't last 10 minutes, according to a reader who emailed me his disappointing story. What's more, this is the second seat post he's broken in exactly the same location. The first one was a Look Ergopost 2Ti which lasted him an unsatisfactory 2 years. For appeasement and warranty honor, he received the "10 minute" Ergopost 4 from Look USA.

The product, by design, appears to be a monocoque setback post with weight of 170 grams and allowing 60 mm of fore-aft adjustability. I haven't seen this in person but Richard Feltner from Florida (the user) told me that while shining a light onto the post, he made out what appeared to be a two piece design with an upper "casting" or "forging" of CF joined to a tube section.

The catastrophic failure happened a little below the setback curve and internally, this is where Richard spotted an intersection or joint between two sub-assemblies that make up the post.

When he had initially received the Ergopost 4 from Look, he had made sure there were no scratches, cuts or deformations as stress risers before installation. He had then installed the post in neutral setback, adjusted it and torqued it to specs using the same OEM collar clamp that Look specially recommended.

Setting his 170 lb self on the bike, he went for a ride on the back streets of his residence. To his utter dismay, within 10 minutes, he heard the distinct crack. The saddle started rocking. The instantaneous cadence increase it brought along confirmed to him that the post had broken. He had to ride home standing on his pedals.

Richard contacted Look immediately who promised him, say what, a third post of the same variety! Apparently, Look has had him in the clutches of their word, assuring him that this is the most bulletproof item they manufacture. He doubts it after two unsafe experiences.

Check out the pics of the strong breakages. Meanwhile, if any of you readers have the same seat post, please fill us in with your honest experience of the product. If others have had similar issues, feel free to tell me about it through a comment. This will be helpful to Richard and a lot of other users. No one wants a seat post forcefully stuck into the rear end.

To Look Cycle : It's time to start "looking" into this issue.


Look Ergopost 2Ti (Richard's first seatpost)





Look Ergopost 4 (Richard's replacement under warranty)









ADDITIONAL READING :

Thomas Masterpiece Seatpost Failure + Mechanics Of A Seatpost Clamp
AX-Lightness Daedalus Seatpost Failure
Breaking Look KEO Pedals
Inspection Of Dave's Carbon Fiber Road Bike

* * *

1 Saturday Stupidity VIII

Click to zoom















FOR OTHER 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

* * *

33 Tour Down Under Or Tour Down Armstrong?

Like most cycling fans, this is the time of the year in which I have pull out of the winter slumber and get into the "zone". You know what I'm talking about. Drum-roll. the international pro calender is starting next week with the TDU and there are some big names on the starting list.

So I'm all excited and I go alright, cool so where can I watch the TDU in the U.S?

I wish I hadn't found out the answer. For learning that this sweet little race is going to be man-handled by VERSUS yet again instilled a reaction likable to an excited male organ turning droopy in sexual indifference.


Some of you out there may be pretty disappointed to learn that the "voices of cycling" trio Liggett, Sherwin & Roll could be planning on unleashing the same love triangle with Armstrong that they had all throughout last year.

"Oh Armstrong did this...I'm so happy."

"Oh Armstrong did that...I'm even happier."

"Oh Armstrong did something in between this and that you may want to know..."

"And...there we have Armstrong, he's looking great, look at his shining bottom..."

Someone save us all.

If this is going to be an all-out orgy between professional commentators and the controversial "face of cycling" like last year, expect yourselves not to learn a word about the brighter side of the Aussie pro scene, about all those younger upcoming talents who are the pillars of this sport tomorrow.

More disappointment comes in the following quote from the Cycling Fans website :

"In its second year of Tour Down Under coverage, VERSUS will air daily 30-minute stage re-caps from Jan. 19-23 at 6 p.m. ET as well as a one-hour show at 6 p.m. ET on Jan. 24 for the final stage.....VERSUS' daily coverage of the Tour Down Under will be supplemented with a half-hour special on Jan. 23 at 5:30 p.m. ET titled Lance Armstrong: The Next Chapter. This must-see special will feature Paul Sherwen's exclusive one-on-one interview with the cycling legend in which Armstrong reveals his thoughts of his performance in 2009 and what fans can expect from him in 2010. The special will re-air on Jan. 24 at 3:30 p.m. ET."

I think the idea is preposterous. Is Lance Armstrong the "next chapter" of cycling? What is there to talk more about his next chapters when we already know so much about this hot bag of air from his multiple movies, his TV show appearances, his Youtube videos, his multiple books, his multiple interviews, his thousands of twitterings and from his multitude of yes-men who are probably collecting a good sum themselves publicizing his name?

I mean, this man's PR scheme is on steroids with a capital S and it is just the same old, cheap stuff overwhelming cycling wherever it goes. Nothing is going to change I guess.

Like many, my only hope here is that he at least gives his "Global Cancer Awareness" propaganda some more priority instead of taking the stage to yap about himself. What has the Global Cancer Awareness done so far in the Globe? Are people more aware now of cancer than before? Give the public some concrete numbers for a change. Yes, everyone wants to know.

Armstrong publicized in a grand press conference in 2008 that for two years prior to his comeback, he had "sat and studied a global cancer awareness strategy" because he was so overcome with the epidemic, and the motivation to get back on the bike would have been specifically to implement it. "That would be the number one goal," he had said.

In that same press conference, he admitted he would talk with the Prime Minister of Italy during the Giro to initiate an anti-cancer program over there. He said he would organize a Global Summit at Paris. He said he would organize this initiative and that initiative for the respective communities in the countries he raced in. Did those really happen? Not sure.

And then he went on about his comprehensive anti-doping program with Don Catlin, which we all now know, doesn't exist anymore. So what about the rest of the story? Is he sticking to cancer awareness or did that come apart too? Sadly in 2009, we heard more about his media antics with rival, a composed Contador, than we did about the specifics of "Global Cancer Awareness".

One should really think about what motivations Armstrong has with the TDU, especially when he embarked on racing here in 2009. Give this one a critical thought for a moment.

In grand manner, Armstrong had remarked in 2008 prior to his comeback that he would essentially race for free. During the infamous interview with Vanity Fair, he spun to Douglas Brinkley the following :

"Everybody in cycling has a team and takes a team salary. I am essentially racing for free. No salary. No bonus. Nothing on the line.… This one’s on the house. And you know what? At the end of the day, I don’t need money.… Not only will I be fine, my kids will be fine, my grand kids will be fine.”

To Joe Public reading that snippet from this interview, it might have appeared that Armstrong was being humble and truthful for a change and was not interested in making profits off this whole "comeback 2.0" affair. Was Joe Public right? Not if he really understood Armstrong's dictionary.

So the reality?

For 7 days of being sheltered in the peloton at the TDU in 2009, it was reported by Crikey that Armstrong pocketed a cool sum of upto AU$3 million (US$2.7 million) in taxpayer money. Of that, he was immediately paid US$500,000 by the South Australian government after his announcing while the rest came later after the race. What is certain is that he received AU$1 million (US$925,000) just to stand somewhere and talk in general about cancer.

The SA Tourism office covered up the money trail in public by saying that disclosure of his income was not possible as they considered it "commercial in confidence". What does that mean? It means you don't have to reveal what you don't have to reveal. Simple. Besides, Rann's control over information is so overwhelming that Bob Gosferd noted on Crikey "...even senior Ministers in his government don’t know how much the Texan is being paid."

You would think he would have donated a little bit of those profits to his charity foundation. In fact, that's what he had told Premier Rann Press who eventually gave the same story to the media at TDU. But apparently, that wasn't the case as he ended up pocketing it all for himself.

Later, knowing that anger and concern were being raised in Australia over this sum of money he had earned, Armstrong quit dodging questions and finally deflected his initial admission to Vanity Fair that he was going to race free since he had enough money and all that rubbish. He told the NY Times :

"I'm not donating the fee to my foundation but treating it as income."

Just like that. Keep in mind such earning excesses came at a time when wages of the peloton itself had decreased by 40% in recent years. And the excesses were earned for what exactly? For doing some minimal discussions about the cancer epidemic and then finishing 64th at the race, in the back somewhere.

And 3 million is just one piece of the pie. For the Giro, the Italian Tuttosport reported that Armstrong was getting paid 2 million Euros (US$2.87 million) to show up. What he made for the Tour of California and the Tour of Ireland are shrouded in secrecy. Its anyone's guess, but don't cut yourself short. Start counting in six figures.

Considering Armstrong's long revisionist history and attitude of outright lying, one would have to study him with critical thought and gut instincts instead of simply drinking the Kool-aid he spills out in PR campaigns.

It would not hurt if cycling fans and other members of the Australian public thought critically about what Armstrong's real agenda was at the Tour Down Under last year. How much does he and the people who publicize him stand to make this year by shuttling around his ego, much less the whole anti-cancer propaganda? And then the big question is, is that your money and is it being well spent?

For the rest of us, let's hope VERSUS provides a balanced coverage of professional cycling from now on, instead of bootlicking Lance Armstrong.



ADDITIONAL READING :

Valverde, the “Texan”, TDU2010 And What The Australian Didn’t Tell You…

* * *

16 Why Do Hate Groups Toward Cyclists Exist?

Interesting things happen on Facebook. Readers will have known by now that there is a 35,000 strong group on the social networking website that goes by the name of "There's a perfectly good path right next to the road you stupid cyclist!"

In direct opposition, (drum-roll) sprang up another group called "Help remove this hate group against cyclists!" that is exponentially increasing its membership as we speak and ironically, is no less of a hate group than the first.

For instance, you'll find members here bad-mouthing the admins of the first group and calling for desperate measures to have it taken down. Defense lieutenants suggest the sabotage of computer systems, among other militant tactics. Below, an example :


Earlier, I had asked the fans on my own Facebook fanpage to join the second group hoping that if this group accumulated a lot of members, perhaps Facebook would consider taking some sort of action against the first group. But over the weekend & rightly so, I struggled to differentiate between the two groups.

Is it disturbing that hate groups exist anywhere for that matter? Sure. But on Facebook, hate is one of the most common used words anyway. So much so that more than a million or so members are rallying for the website to pamper them with a "Dislike Button". Oh boy.

What's more, there's a fanpage for "Killing", "I hate bicycles", "I hate cars", "I hate God", "I hate stupid people", "I hate black people", "I hate Steve Jobs", "I hate Jews", "I hate Arabs", even "I hate myself".

The subjects for Facebook hate groups are immensely wide. They cover everything from ice cream to computers to complex racial prejudices you and I would rather not talk about in public. In short, Facebook members have managed to hate almost every thing there is to hate in the world.

So for Facebook officials to think about deleting one specific group, they would have to ban many of these other offshoots of hate with equal reason, groups where perhaps the admins themselves don't encourage hatred and violence, but the members who are ensconced there do. If Facebook doesn't do so, anyone can rightly accuse them of displaying double standards.

For a start, Facebook has already issued a statement refusing to delete the hate group towards cyclists in question. So it's likely it won't happen. Even if they did, that won't eliminate the hate. People are going to hate wherever they want, why limit it to Facebook?

Now it is hardly surprising why we cyclists are a sensitive bunch of whiners when something like this happens. Cycling as a mode of transport is just growing in Western countries. In many of these places, cyclists are a minority group trying to get established on 4 feet of side road or narrow shared pathways.

Day in and day out, you hear of cyclists being seriously injured, maimed or killed on the roads. In November last year, the Guardian reported that the number of cyclists killed on English roads over a 3 month period in 2009 had increased by 19% from that of 2008. A staggering change indeed, if true.

Trying to intentionally harm cyclists is a serious offense and punishment is growing to be severe. The message these days couldn't be clearer. A doctor in California who was recently found guilty of such a heinous act was sentenced to 5 years in prison. It was big news, one that was welcomed with reluctance by a nervous cycling community. They expected more!

But neither are cyclists an innocent bunch. The NYT has reported several times about brash behavior from urban cyclists. I myself did highlight one that was featured on the front page, one which was particularly embarrassing to read. In places like Victoria - Australia, punishment for such rogue riding is severe, from hefty fines to jail terms.

To add plenty of drama on the side, independent cycling groups lobby for an anti-car world. They organize critical masses, block traffic, ride naked on the streets, come up with fine jerseys such as this one to make the message clear - that no one group is exclusively funding road tax so you know what, we are the traffic too so shut up and get along.

Motorists on the other hand continue to violate traffic laws, kill pedestrians and cyclists and spew hydrocarbons into the atmosphere to often travel what are frequent, small distances (an inefficient way to use gas).

To top it all off, newspapers such as Daily Mail publish anti-cycling content and victimize the minority, for no obvious reasons but fun.

One has to recognize that it is in the middle of such lawlessness and all the hullabaloo on the side that the law itself is trying to bring some sense of balance. For the rest of us perfectly law abiding citizens who ride bikes but also drive cars, all this comes in the form of news or entertainment. It could even offer us a basic, nevertheless important economics lesson.

Economics has it as a fundamental idea that resources in this world are limited. Land, labor, capital etc., all come in discrete quantities. Between cyclists and motorists, the road is the predominant resource that is shared. And you can have only so much people on a given quantity of road.

As an affluent middle income class grow, they want to buy and use more cars. As health and environmental consciousness rise and advocacy for cleaner transport grows alongside, more folks turn to the alternate modes of transport such as the metro and bikes. As oil prices skyrocket, people start driving less. As oil prices drop, people may or may not start driving more but cycling could continue its growth.

As cycling increases, it feeds itself. There is now more apparent safety for members of the community, hence the numbers of cyclists increase. They might start taking liberties while riding two abreast. As motorists crash into them and take them out one by one, the numbers decrease. Alternatively, as cyclists ride dangerously without abandon, their numbers decrease.

You see, the point I'm trying to make here is that the road sign you see on the left holds a simple truth - share the road, for it is a limited resource.

As long as the status quo is preserved, resources are not going to increase out of thin air to accommodate transportation growth patterns. This inevitably leads to more conflicts between cyclists and motorists. Its like the sharp struggles of life that happen in the animal kingdom between territorial creatures, creatures that have to share one piece of land.

In this limited world that has to be shared by cyclists and motorists, numbers rise, numbers fall, some people die, others break bones, and still others are taken to jail or fined. Where is the equilibrium to this dynamic world?

To find that out, you'll have to create a model built on mathematics and consider cyclists and motorists as a species trying to gain control of a shared area. You know, its like that neat predator-prey model you studied about in differential equations class that started out with a list of assumptions and described the world of the eater and the eaten. Or it's like Conway's Game of Life, a computer program that provides a great insight into evolution, emergence and self-organization of life.

I did want to go into this interesting topic more mathematically but perhaps I'll attack that another time. Meanwhile, perhaps you readers could think more about the interesting mathematical patterns you see in the cyclist-motorist rivalry and what it shares with other more fundamental aspects of life?

Bottom line - one aspect is clear in my mind after this discussion. The disturbing rivalry between motoring and cycling warrants a need for more advocacy and a tougher call for tolerance, sacrifice and respect from both parties involved. Share the road. Otherwise, stay at home.

ADDITIONAL RESOURCES :

Cycling Safer Than Walking Down The Road In Q2 2009 - Mark @ iBikeLondon
Unjamming Traffic With Computers - Scientific American (Oct '97)
Traffic Flow Theory - Federal Highway Administration

* * *

55 How Cycling Pro's Defeat Anti-Doping Control

There is doping in cycling, no doubt. However, as we have it, there's a fine line between talking about it and not talking about it. If you don't talk about it, like they say, ignorance is bliss and you have a million happy cycling fans who know little of the real going on's of cycling. If you talk about it, suddenly you're a hater of professional athletes and you are giving the business of cycling a bad name.

As the author of this blog, I cannot live with ignorance and naivety. Inaction is worse than silence. If we don't understand what is really going on in our sport, we will not have the power to help clean it up as fans. The best way to understanding the doping issue is through education.

This Guest Post by none other than ex-racer Joe Papp (also a blogger) describes at length how racers subvert and escape doping control. Joe needs no special introduction. He's been there, done that and I think he's a fine candidate to tell us how slippery the pro's can get from the system. How are athletes tricking our intelligence into believing illegitimate sporting performances? Well, find out by reading the following eye-opening article.


When Ron asked if I would be willing to write a guest post for Cozy Beehive, I readily accepted, thinking I’d be able to oblige within a few days. It’s funny how life throws curve-balls, because it’s been a lot longer than that since I promised the piece, and several more drug scandals have hit cycling during the interim. The topic is but a general overview of some of the ways by which riders attempt to defeat anti-doping controls – a course of study that should have been read by Tom Zirbel and Nicklas Axelsson (at least according to their A-sample results).

The counter-measures an athlete will deploy in hopes of beating a doping control are all drawn from the same bag of dirty tricks, though the specific tactic ultimately depends on which doping product the athlete has ingested and where he can find a possible weakness in the testing protocol.


I. SPIKING WITH ENZYMES

Axelsson is accused of taking EPO, which is detectable via urinalysis. About the time of Operation Puerto, however, riders were defeating the urine-based EPO test by spiking their samples with small doses of enzymes like protease, which break down proteins — including EPO — in urine in the space of a few minutes.

Typically an athlete would conceal a supply of protease powder in his jersey before a test, transfer it to his fingers with a quick movement and then urinate over his hand into the sample bottle to ensure that the test is meaningless. Alternatively, once doping control officers (DCO’s) began to insist that the athletes wash their hands first, male athletes switched to secreting the powder under their foreskin and transferred it that way.


II. ILLEGAL POWDERS

A more sophisticated method was used in Spain, where, according to an acquaintance of mine who rode for Kelme during the Fuentes years, the procedure that Jesus Manzano described was their preferred tactic.

Manzano : "There is a red powder that's made in an illegal lab just for them outside of any controls which destroys the urine sample. This powder comes in the form of a grain of rice that we put into our penis before we pee…”

III. EPO MICRO-DOSING

Given that the UCI is now wise to this subterfuge and has instructed its DCO’s to be on the lookout for it, the best bet that a rider has for beating an EPO control is to micro-dose. EPO, typically produced from cultured animal cells, is detectable in urine for less than a week. A decade ago, before the development of the urine test, riders would gorge themselves on large quantities of EPO during the inter-race periods to raise their hematocrit levels, and re-dose prior to competition.

Now, there is a growing trend towards micro-dosing, where athletes take small, barely detectable amounts of EPO to maintain the slightly elevated levels with which they enter competitions. The UCI Biological Passport will make it difficult for dopers to manipulate blood parameters sufficiently to enhance performance without tripping a reporting threshold, and even with micro-dosing there is now no guarantee that minute changes in a rider’s hematological profile will go unnoticed. And if changes are noticed, watch out! The hematological profile itself can be used to open a doping case against a rider.

The UCI explains:

“The haematological [sic] profile opens new doors in the detection of riders who choose to manipulate their blood to unfairly enhance their performance. The scientific assessment of a rider’s profile applies similar principles to those used in forensic medical science to determine the likelihood of guilt. Once sufficient evidence is gathered which determines guilt at an agreed level of certainty, scientific experts will recommend that the UCI open disciplinary proceedings for an anti-doping rule violation. It is expected that a profile of six tests will enable the detection of blood manipulation. In some cases, a fewer number of tests may be needed to detect doping.

Such a violation will be based on Article 21.2 of the UCI Anti-Doping Rules – “The use or attempted use of a prohibited method". To support this rule, the List of Prohibited Substances and Prohibited Methods maintained by WADA is incorporated into the UCI Anti-Doping Rules. Section M1 of the Prohibited List prescribes the “enhancement of oxygen transfer through blood doping” as a prohibited method.

The expected sanction for a first offence under this rule is a suspension from competition for 2 years. In addition, the detection of abnormal levels will cause a rider to be declared unfit and to be suspended from racing for an agreed period of time."

IV. URINE SUBSTITUTION

Not nearly as glamorous as spiking urine samples or manipulating blood profiles to thwart a doping control is the process of urine substitution, whereby an athlete’s dirty sample is substituted with that of another person (who presumably hasn’t consumed banned substances) or a synthetic sample.

While the Italian team I rode for never switched one flask of human urine for another, they did keep cartridges of synthetic urine in the team car in case of a random control. The powder within the cartridge would be poured into a small Mylar bag, and then, with the addition of lukewarm water, a “safe” sample would be ready. At that point, it was up to the rider and his team attendant to distract the DCO or otherwise subvert the sample collection process in order to deliver the synthetic urine in place of the rider’s own “hot” pee.

That same team was the one who gave me dose of synthetic urine after the final stage of the UCI’s Tour of Turkey in 2006 and told me to catheterize myself prior to reporting to doping control. I’d won the final stage, and obviously understood that the team believed I had something in my body that would produce a positive result, and they didn’t want to take the risk of even sending me to doping control without some kind of countermeasure. I couldn’t do it, however. There was no way I could self-catheterize myself, and so my career approached its end. Had I catheterized myself I would have committed a doping violation just as serious as if I’d been caught with EPO in my pee. For the World Anti-Doping Agency’s Code clearly prohibits the following (quote) :

"M2. CHEMICAL AND PHYSICAL MANIPULATION

1. Tampering, or attempting to tamper, in order to alter the integrity and validity of Samples collected during Doping Controls is prohibited. These include but are not limited to catheterization [sic], urine substitution and/or alteration.

2. Intravenous infusions are prohibited except in the management of surgical procedures, medical emergencies or clinical investigations."

V. BRIBERY TO "CHANGE" OUTCOMES

Lacking the sophistication of a blood doper like Ferrari are the brute force cleaners who are called in to the sample collection site near the end of the session. When the guilty athlete can’t suppress his hot urine anymore, an agreement must be reached between all the stakeholders, like the Doping Control Officer, Lab Director, Race Director, rider, Team and Assorted Flunkies.

Quite simply put, cash changes hands based on the guarantee of someone in a position of power to ensure the outcome and the positive test is never declared, or, more likely, flushed before it is ever analyzed. The upside for the cheater is that were sample collectors to visit that same race the following season, he would probably be able to prepay to avoid any doping hassles.


VI. HIDING WHEREABOUTS

Of course, a rider might attempt to subvert a control before he was ever called to the collection station at a race. Providing inaccurate whereabouts and information so as to avoid out-of-competition testers (Michael Rasmussen), evading sample collection (Riccardo Riccò) or refusing it after having been notified of selection would probably not save the guilty, but would certainly provide fodder for the media and blogosphere.

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I hope Joe's article convinced you that although difficult, there are multitudes of elaborate schemes dopers follow to defeat the system and lead us to believing in fantastic myths. As an inset, there is bribery taking place to twist outcomes bad to a racer's reputation as Joe mentioned above.

Cycling has now grown to be a sport where its definitely tough to make it to the cream of the crop, but once you slip in, the rewards for high performance promise to be high, involving millions of dollars of direct payouts and endorsement deals. There is no doubt in my mind that cheating at races and then collecting such prizes is akin to fraud and embezzlement, no different than that in any other aspect of human endeavor. Perhaps at this time, it would do the dopers good if they would study what exactly happened to Bernie Madoff at the end of an incredible fairytale. A fairytale setup in such a way that it would inevitably spiral into a mega catastrophe for a nation.

Do you have any additional insights to share? What else do you think dopers are doing to subvert doping control measures? You're all welcome to chime in.

ADDITIONAL READING :

Suspect Samples Destroyed In Guatemala : Cycling News
The Doping Devil : Prof. Verner Moller (e-book)

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17 Bicycle Frame Stiffness : The Numbers

Twelve top end bicycles that you can buy for money and the wheelsets they had were recently thrown into mechanical tests by the German magazine RoadBike.de. Which means, lots of interesting figures for you guys with fat wallets and zilch to lose. For people modest with finances like me, I just like to see the data that these state-of-the-art bicycles are putting out these days.

Methodologies of the tests maybe read here, if you know German. The bikes were all sub 6.8 kg. The models and the figures they posted are shown below.

• BMC Team Machine SLR01 : Link
  
• Canyon Ultimate CF SLX Ete 201 : Link
  
• Cervélo R3 SL : Link
  
• Cube Litening Super HPC Race : Link
  
• Focus Izalco Team Milram : Link
  
• Haibike Affair RX : Link
  
• Lapierre Xelius 900 : Link
  
• Red Bull Carbon X-Lite 8800 : Link
  
• Scott Addict R1 : Link
  
• Simplon Pavo Red : Link
  
• Storck Fascenario 0.7 IS : Link
  
• Trek Madone 6.9 Pro (this is what Contador won the '09 Tour de France on) : Link
  

Bottom Bracket Stiffness

Headtube Stiffness

Fork Stiffness

Comfort Related Stiffness (lower stiffness, or more the compliant, is better)

Wheelset Stiffness (front & rear respectively from left to right

Observe that Mavic R-Sys, whose notoriety is second only to the spectacular failures it suffered out on the field, posted 5% lower stiffness than the average of the 12. Overall, the Canyon Ultimate was rated the best bike in this test.

Readers may recall that last year, I posted stiffness data for Museeuw's MF5 Flax-CF bike. I'm also interested in what another exotic frame - the Delta 7 Isotruss - shows in comparison. So here are those two that I plug into one chart. Really interesting.

Delta 7 vs Museeuw MP5 Flax. Courtesy for data : German Tour Magazine

The Ascent bike is described by the company as "extremely stiff" due to its structure and so light it is "exhilarating". However, the numbers Museeuw's Flax frame has posted put the isotruss slightly down. Both frames are however no where in comparison to the bikes above for bottom bracket and headtube stiffness, although they seem to be relatively more compliant for comfort. The flax bike is second only to the BMC Team Machine in comfort and I wonder if the benefits of the flax are tied into this.

This exercise only compares stiffness of these frames. Do remember that stiffness is not the only yardstick by which bicycles are measured. Lot of stiffness is beneficial in some spots but unnecessary in others. Lot of stiffness may suit some riders but not others. See, if stiffness alone were the holy grail of bike design, we'd all be riding on reinforced concrete by now. And you'll need lots of chamie cream for that.

ADDITIONAL READING :

Rational Bicycle Frame Design : Giving Consideration To Functionality
Buckling In A Bicycle Frame
Dynamic Ride Comfort & Measuring Vibration In Bicycles
Carbon Nano-Tube Technology In Bikes
Nanotechnology Application In Bicycles : How Good?

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13 Cycling In Heat & Helmet Cooling Power

Burrr. Its a chilly, white winter here where I live and in want of some heat, I decided to bring some 'heat' into today's post! I'll talk a little about the cyclist's elements during hot weather cycling and will seek to understand what role certain elements of our kit, like helmets, have on cooling.


CYCLING IN HEAT

When a cyclist gets out for a ride during the pleasant summer months, the modes of heat transfer seen between them and the environment is of the following order. You might think it is easy to fathom, but it really isn't.

There's many packets of energy entering and exiting and bouncing off here and there, from the thermal radiation from the sun to the heat flux in the skin. Overall, what we see is a complex thermodynamic system in action that tries to approach homeostasis. Here's a diagram :


Some of these elements may be familiar to us. Taking a break after riding, you can feel the hot sun on your skin. Comfort and discomfort are associated with humidity. When the relative humidity and air temperature are both high, the rate of sweat evaporation happens more slowly and we sense a higher temperature than the actual temperature of the air. The temperature we ultimately feel is governed by the temperature-humidity index (THI), also called discomfort index.

Now there happens to be an easy formula (though there are several more complicated ones) you can use to calculate THI before your rides.

THI formula developed by Clint Brookhart, P.E

where H = % humidity
Tf = Temperature in Fahrenheit

As the temperature gets higher, low %'s of humidity can result in an index that is much higher than the actual temperature. But the above formula does not take into account the reverse air cooling taking place when you ride your bike in a breeze.

Another aspect of the image above is the thermal radiation off the ground. Because of its dark color, roads happen to be good emitters and this infrared radiation varies proportionally as the fourth power of road surface temperature. You can get an idea of the energy emitted per unit surface area, or emissive power, by using the Stefan-Boltzmann law.


CLOTHING

With regard to the emission properties of colors and surfaces, you and I were taught from early years in school that light colors are always good in sunny weather for better reflection. Yet our sport is one of multitudes of color, dark color.

It always struck me as odd how we riders have managed to live with dark colors in hot weather. The saying has always been to choose fabrics with wicking properties. These days, companies like Campagnolo are trying to capitalize on the apparent discomfort of dark clothing by incorporating fibers with UV ray protection. It seems to me a majority of us don't really think about apparel's effect on heat transfer and prefer more to wear matching kits, including helmets. The predominant color for shorts among men and women is black, but that seems to be for obvious reasons.


HELMETS

Which brings me to the question of helmet color. Are light helmets better than others in terms of thermal behavior? And how many cooling vents are optimal? This must be an important question, after all the helmet sits on a cyclist's head and part of the body's internal temperature regulatory mechanism is contained inside the brain.

The question posed above cannot be easily answered. In 2006, a paper in the Journal of Sports Sciences from Bogerd et.al noted :

"Given the large variation in designs on the market, there is no widely adopted systematic approach to designing bicycle helmets for optimal ventilation. A quantitative survey of a large number of modern helmets is required to understand the role of "common sense" parameters, such as the number of holes in the helmet, since the helmet geometries are complex. In particular, the importance of forced, rather than natural, convection complicates a qualitative a priori analysis."

The paper referenced above isn't a bad read. It reports on the heat transfer, or forced convection cooling power, of an ensemble of 24 helmets. The study was done using an artificial headform. Apart from vent cross-sectional area and helmet channels, even the auxiliary elements of helmet design, such as the straps, and biological parameters like facial measurements and hair thickness have significant influence on ventilation properties, it seems. In the end, they concluded that "the wide variation in ventilation performance in the present ensemble serves to emphasize the lack of systematic understanding of the principles behind bicycle helmet ventilation."

As difficult the task above of studying helmet ventilation was, it didn't really seek to answer the question of helmet color and its effect on heat transfer.

A simplistic thermal test between a black and a white helmet was done back in 2000 by Terry Morse of California. The test aimed to answer the question of whether or not a black helmet is hotter than a white one of same design when worn in direct sunlight, both while at rest and while moving.

Terry placed a temperature probe at the crown of a Styrofoam head form, and put the helmet on the head. He then hung a halogen lamp 5" above the helmet, turned a household fan on high speed (6.5 mph), & recorded the temperature every minute until it stopped changing. He then carried on the same test with the fan on low speed (5.0 mph), and finally with the fan off. He did these three tests thrice for a black and a white TREK "Vapor" helmet and a bare head situation.

What he found was interesting :

1. In the air cooled phase of the experiment, the bare head form showed the least temperature change (delta F) from ambient temperature while the head form with a black helmet showed the highest delta F. In fact as the airspeed was decreased, the black helmet's delta F kept increasing before it stopped showing any changes.

2. About 16 minutes after turning off the fan, the delta F in the base head form was fastest and highest. It was the most reluctant to stop gaining heat while the black helmet was the best emitter of heat, in other words, there was more cooling with a black helmet on. But Morse maintains that the heating rate was very close between both black and white helmets.

Graphs showing the temperature change (dF/dt) in high, low and zero fan airspeed. About 16 minutes after turning off the fan, dF/dt in the base head form was fastest and highest (green line). Click to zoom.

Studying the effects of helmet on head cooling is no easy matter. While the test above is simple in nature and a Styrofoam is certainly no human head, do you think it makes a reasonable conclusion that you're better off with something covering your head in conditions of little wind speed? What else would you consider when designing & selecting a helmet for cooling? Please feel welcome to discuss with comments.

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