a reliable and sleek bicycle odometer

Knowing how far you've gone is very useful when cycling. It can help you find your way with the help of a map (for ex. to “turn right after 1.5 km”), find which of a set of alternative routes is shorter, know how much workout you had, and estimate how far you still have to go on your trip. A classical odometer offers two counters, one resettable “trip” counter and one non-resettable “lifetime” counter, both having their own scale. The odometer proposed here shows just those two counters in the form of black digits printed on a white background, the digits sliding behind a little window. This has the advantage of being very readable, high-contrast, good-looking, robust and not using any power to display the numbers. The counting up is done using impulses from the bicycles hub dynamo and uses almost no power from the wheels. Resetting the trip counter is done mechanically with the user's gesture being the power-source. This construction ensures that the counter always displays the current mileage and is resettable even when the bike is not running or has not been running for a long time.

Here are some advantages of the proposed odometer:

• high readability, always-on display
• ease of use with only one dial (or button) to reset the counter
• no parts attached to the bike wheels; only a small cable branching of the lighting system
• no battery needed, therefore no need to swap batteries
• very little energy use which does not noticeably increase the loss power of a normal hub dynamo
• handle-bar mounting in-between brake lever and grips for sleek design, robustness, and discouraging theft

Here's a very sketchy drawing of how the odometer integrates with the handlebars. The top line shows XXX.X km and the bottom XX XX0 km.



And here some more detailed design information: the trip counter has four digits, the smallest counting 100 m. The life-time counter also has four digits with the smallest counting each 10 km. The longest trip will therefore be 999.9 km, which has been chosen because some people ride more than 100 km in a day and other might want to count trips of more than a day. The life-time counter will relapse to 0 after showing 99'990 km which is enough for most bicycles, although not enough for people who really ride a lot and keep the bike for more than a decade. (For an example see Rohloff Wanted day.) For those people there will be a luxury version of the counter with two times five digits: the trip counter measures each 10 m and the life-time counter goes up to 999'990 km. I would think that some people would buy this extended counter just to show off how far their bike is designed to go!

The two photos above show historic counters with little disks carrying the digits. To make the counter slimmer to integrate it better with the handlebars, the disks can be replaced by a little strip that turns around two pins as shown in the pseudo model on the right. Designing the electronics for this device will not be totally trivial because it has to deal with a wide variety of currents and voltages coming from the dynamo at different speeds and with lights on or off. There will several hidden digits to account for fractions of the distance displayed. Alternatively those values could be stored in some digital solid-state memory of a couple bits. In any case, storing this information won't use any power. The only power supply will be to increase the invisible counter which at every full interval will increase the visible counter. I wish I knew somebody who could figure those electronics out for me!

A variant with speedometer would use a classical needle to show the bike's current speed on a scale and it would additionally have a counter for the time of the current trip (accumulated time with speed >0). Then a second needle would show the average speed of the trip (which is the dividend of trip length and trip time so far). This second needle would be held in place with a gearing mechanism that doesn't need any power either. So when you stop the bike, the current speed will drop to 0 and stay there while the average will just stay where it was. When you sleep during a cold night that would drain any batteries and come back the next morning, the needle will still show your trip's average speed. I think that's reliability! And that's cool!

PS: Germersheim, I come!

U-Bahn Zürich

Zürich gilt unter Verkehrsexperten als leuchtendes Beispiel für guten öffentlichen Nahverkehr, nicht zuletzt weil sich die Bürger in den 70er Jahren explizit gegen eine U-Bahn entschieden und damit das sehr benutzerfreundliche Tramnetzwerk erhielten. Andrew Moglestue hat eine interessante Zusammenfassung der Züricher Projekte für Tram-Tunnel (aus den 60ern) und U-Bahn (aus den 70ern).

Moderne Straßenbahn in der Innenstadt von Zürich. Man bemerke, dass diese Straße auch eine Fußgängerzone ist.

Manche glauben auch, dass Zürich damals eine einmalige Chance verpasst hat, eine U-Bahn einzuführen. Hat Zürich seine Zukunft verspielt? Dazu findet sich ersten Teil von Andrews Zürich: A city and its trams folgendes schönes Zitat: „Zürich's tram system has acquired an iconic status; 65% of people commuting within the city do so by public transport, with only 17% using cars [1].“ Dazu kann ich nur folgende einfache Frage stellen: welche Stadt, die eine U-Bahn hat, erreicht solch traumhafte Werte? In Westeuropa und Nordamerika kenne ich keine. In Asien gibt es das vielleicht, aber mit Peking und Manila will sich Zürich lieber nicht vergleichen.

Zwei S-Bahn-Züge in Zürich Stadelhofen

Die eher kleine Stadt Zürich hätte gern eine U-Bahn, um sich mit Stuttgart, München oder Wien vergleichen zu können. In dieser Größenordnung liegt Zürich – trotz seiner internationalen Bedeutung als Bankenzentrum und Shoppingvillage für neureiche Russen – nun mal aber nicht. Ein besserer Vergleich mögen die Städte Karlsruhe und Mannheim sein. Außerdem ist zu sehen, dass im Großraum Zürich nur ein Drittel der ca. eine Mio. Einwohner in Zürich selbst leben und zwei Drittel im Umland. In deutschen Großstädten ist das Verhältnis umgekehrt. In Berlin wohnt wohnen drei Viertel der Großraumbewohner in der Stadt selbst. (Und vom Rest viele allein in der Stadt Potsdam.) In München sind es immer noch mehr als die Hälfte. Nur Stuttgart hat ein zu Zürich ähnliches Verhältnis von Stadt und Umland. Dabei ist Stuttgart aber immer noch zwei bis drei Mal so groß.

Tram-Stau in Toronto. Wenn es in Zürich so aussähe wäre wohl eine U-Bahn gerechtfertigt.

Zuguterletzt sei nicht verschwiegen, dass auch in Zürich noch Optionen für Tram-Tunnel bestehen. So gibt es am Hauptbahnhof eine U-Bahn-Station aus den 70er Jahren, die zur Zeit für zwei S-Bahn-Linien benutzt wird, von denen eine (die Uetlibergbahn) das gleiche Stromsystem wie die Züricher Straßenbahn verwendet. Es ist also durchaus möglich, dass in dieser Station irgendwann einmal die Uetlibergbahn und Straßenbahn gemeinsam verkehren. So wie das die Forchbahn bereits tut.

neuer Kettenschutz für Speedy

Speedy 2006 in Berlin

Nachdem mir mein Chainglider im letzten September abgefallen ist (genauer gesagt: er kam ein paar Mal zwischen Kette und Blatt und beim letzten Mal war er dann zerstört), suche ich jetzt nach einem neuen Kettenschutz. Den Chainglider würde ich gern wieder nehmen (und zwar mit einem zusätzlichen Clip, der das in-die-Kette-kommen verhindert; diese ist bei einigen Herstellern, z.B. Fahrradmanufaktur, sowieso schon Standard), allerdings möchte ich auch eine andere Blatt-/Ritzel-Kombination.

Der Grund ist ganz einfach: mein aktuelles Ritzel ist mit 14 Zähnen für die Shimano-Nexus-Schaltung eine Sonderanfertigung und sehr schwer zu ersetzen. Außerdem ist es durch meine erste, damals sehr gelängte Kette schon total verschlissen. Ich möchte jetzt hinten ein größeres Ritzel. Erstens, weil es einfach zu beschaffen ist und zweitens, weil bei so wenigen Zähnen jeder Zahn mehr den Verschleiß ei wenig verringert. (Zugegeben, hauptsächlich muss ich besser reinigen und nicht beim Reifenwechsel einen Haufen Sand ins innere des Chainglider schaufeln. Andere Leute haben wesentlich längere Kettenlebensdauern mit ihrem Chainglider erzielt, also warum sollte ich's nicht auch schaffen!?)

Übrigens noch zum Thema Chainglider und zwischen die Zähne kommen: ein Video von Hebie zeigt wie die neueste Variante durch einfache Klick-Verschlüsse noch besser hält. (Falls der Video-Link nicht funktioniert, hier Hebie's Webseite zum Chainglider.)

Jedenfalls soll es nun ein 15er oder 16er Ritzel für mich sein und ich bräuchte dann ein 45er oder 48er Kettenblatt, um dieselbe Übersetzung zu erreichen. Ich würde mich aber auch nicht scheuen, die Übersetzung etwas länger zu machen, etwa 46/15 oder 50/16. Den Chainglider gibt es jetzt auch in einer Variante für 44er Blätter, so dass ich 44/15 fahren könnte. Da dies aber etwas kürzer wäre als mein Status Quo, suche ich jetzt also nach Alternativen zum Chainglider. Die inoffizielle Aussage von Hebie, dass man auch über Chainglider für Falträder nachdenkt, hat für mich keinen Nutzen, da es ja dieses Jahr nun nichts mehr damit wird.

Dahons “biologic freedrive” (yeah!) am 2010 Mµ Uno

Bei Dahon hat man sich zur gleichen Zeit, nämlich neu für diese Saison, eine eigene Lösung entwickelt. Witzigerweise hatte ich gerade kurz vorher über die Zeitschrift Fahrradzukunft von diesem System erfahren. 

Problem des Chainrunners ist allerdings, dass er mindestens ein 17er Ritzel braucht. Das könnte ich zwar theoretisch anbauen, aber mein Kettenblatt wäre dann mit 51 oder mehr Zähnen recht groß. (Obwohl – Brompton hat ja auch 52 Zähne an einem noch viel kleineren Fahrrad.)
Dahon's Mµ Uno kombiniert das System allerdings auch mit einem 16er Ritzel!
Zugegeben: in der 52/17 Variante wäre die Übersetzung etwas länger als jetzt und damit besser als 44/15 mit Hebie. Dazu kommt noch, dass Hebie kein offizielles 15er Endstück für Shimano hat, sondern dieses durch Zurechtschneiden eines speedhub-Endstückes erzeugt werden muss.

In Toronto habe ich letzten Herbst schon ein Fahrrad gesehen, an das jemand selbst ein Wellrohr gebaut hatte. Scheinbar sprechen sich unter Fahrrad-Bastlern manche Ideen noch schneller herum, als sie im Internet zu finden sind! Leider war ich nicht schnell genug, gleich nach Herkunft der Idee und genauen Parametern des Rohrs zu fragen. :-( Mein Vater sagt nämlich, dass die normalen Baumarkt-Wellrohre (Leerrohe zum Verlegen von Kabeln unter Putz usw.) bei Außentemperaturen zu schnell spröde werden und kaputt gehen.

Es sieht also wirklich danach aus, als ob dieses „Wellrohr aus dem Roboterbau“ die beste Lösung für mich wäre. Und nachdem der Chainglider nach mehr als 5 Jahren am Markt schon Standard bei Komfort- und einigen Reiserädern wurde, hätte ich dann auch wieder etwas besonderes: dem Trend um ein paar Jahre voraus. 

one-button usability

My sister has a very well designed electronic kitchen scale which has only a single button to perform three functions:

• switch it on and off
• subtract container weight, that is, switch from gross to net weight
• calibrate the scale

How does this magic work? The single button is labeled  “On Off Tara”. When the scale is off, pressing the button will switch it on and calibrate it to show a weight of 0. When it is on and showing 0, pressing the button will switch it off. In all other cases, pressing the button will recalibrate the scale to show 0, such that when adding more things to weigh, only the added weight will be shown.

This design is not just ingeniously simple, it is also quite robust with regard to the order of steps. For example, one can first put an empty container on the scale, then switch it on, and it will automatically start from 0 to measure what you actually want to weigh.

TV-incited violence vs. Gross National Happiness (must-read for anybody with a social conscience!)

Four years ago, Bhutan, the fabled Himalayan Shangri-la, became the last nation on earth to introduce television. Suddenly a culture, barely changed in centuries, was bombarded by 46 cable channels. And all too soon came Bhutan's first crime wave - murder, fraud, drug offences. Cathy Scott-Clark and Adrian Levy report from a country crash-landing in the 21st century

Here are some excerpts from a 2003 Guardian article about the effects of TV in the country of Bhutan. It is impossible to imagine how a modern Western country would be without TV. Bhutan, however, was without TV until 1999 – it's introduction to the country provides an unprecedented and unique opportunity for study.
The article "Fast forward into trouble" is much longer and here are only some of the most interesting pieces.

April 2002 was a turbulent month for the people of Bhutan. One of the remotest nations in the world, perched high in the snowlines of the Himalayas, suffered a crime wave. The 700,000 inhabitants of a kingdom that calls itself the Land of the Thunder Dragon had never experienced serious law-breaking before. Yet now there were reports from many towns and villages of fraud, violence and even murder.
The Bhutanese had always been proud of their incorruptible officials - until Parop Tshering, the 42-year-old chief accountant of the State Trading Corporation, was charged on April 5 with embezzling 4.5m ngultrums (£70,000). Every aspect of Bhutanese life is steeped in Himalayan Buddhism, and yet on April 13 the Royal Bhutan police began searching the provincial town of Mongar for thieves who had vandalised and robbed three of the country's most ancient stupas. Three days later in Thimphu, Bhutan's sedate capital, where overindulgence in rice wine had been the only social vice, Dorje, a 37-year-old truck driver, bludgeoned his wife to death after she discovered he was addicted to heroin. In Bhutan, family welfare has always come first; then, on April 28, Sonam, a 42-year-old farmer, drove his terrified in-laws off a cliff in a drunken rage, killing his niece and injuring his sister.

Before 1999, Bhutan's society and politics was much different from every other country in the world:

"We wanted a goal different from the material concept of maximizing gross national product pursued by western governments," [Bhutan's foreign minister] says with a beatific smile. "His Majesty decided that, as a spiritual society, happiness was the most important thing for us - something that had never been discussed before as a policy goal or pronounced as the responsibility of the state." And so, in 1998, the Dragon King defined his nation's guiding principle as Gross National Happiness.

The marijuana that flourishes like a weed in every Bhutanese hedgerow was only ever used to feed pigs before the advent of TV, but police have arrested hundreds for smoking it in recent years. Six employees of the Bank of Bhutan have been sentenced for siphoning off 2.4m ngultrums (£40,000). Six weeks before we arrived, 18 people were jailed after a gang of drunken boys broke into houses to steal foreign currency and a 21-inch television set. During the holy Bishwa Karma Puja celebrations, a man was stabbed in the stomach in a fight over alcohol. A middle-class Thimphu boy is serving a sentence after putting on a bandanna and shooting up the ceiling of a local bar with his dad's new gun. Police can barely control the fights at the new hip-hop night on Saturdays.

While the government delays, an independent group of Bhutanese academics has carried out its own impact study and found that cable television has caused "dramatic changes" to society, being responsible for increasing crime, corruption, an uncontrolled desire for western products, and changing attitudes to love and relationships. Dorji Penjore, one of the researchers involved in the study, says: "Even my children are changing. They are fighting in the playground, imitating techniques they see on World Wrestling Federation. Some have already been injured, as they do not understand that what they see is not real. When I was growing up, WWF meant World Wide Fund for Nature."

It is so early in the morning that the birds are still asleep. But Sangay Ngedup, minister for health and education, has been on the path for hours. His gho is bunched beneath his backpack, and a badge with the king's smiling face is pinned on to his baseball hat. In the past 15 days, he has climbed and scrambled over some of the world's most extreme terrain, from sea level to a rarefied 13,500ft in the Bhutanese Himalayas. Is there anywhere else in the world where a cabinet minister would trek 560km to warn people against becoming a nation of couch potatoes? "We used to think nothing of walking three days to see our in-laws," he says. "Now we can't even be bothered to walk to the end of Norzin Lam high street."

For the first time, he says, children are confiding in their teachers of feeling manic, envious and stressed. Boys have been caught mugging for cash. A girl was discovered prostituting herself for pocket money in a hotel in the southern town of Phuents-holing. "We have had to send teachers to Canada to be trained as professional counsellors," says Sangay Ngedup. This march is not just against a sedentary lifestyle; it is a protest against the values of the cable channels. One child's placard proclaims, "Use dope, no hope." "Breast is best," a girl shouts. "Enjoy the gift of sex with condoms," reads a toddler's T-shirt.

Bhutan's isolation has made the impact of television all the clearer, even if the government chooses to ignore it. Consider the results of the unofficial impact study. One third of girls now want to look more American (whiter skin, blond hair). A similar proportion have new approaches to relationships (boyfriends not husbands, sex not marriage). More than 35% of parents prefer to watch TV than talk to their children. Almost 50% of the children watch for up to 12 hours a day. Is this how we came to live in our Big Brother society, mesmerized by the fate of minor celebrities fighting in the jungle?
Everyone is as yet too polite to say it, but, like all of us, the Dragon King underestimated the power of TV, perceiving it as a benign and controllable force, allowing it free rein, believing that his kingdom's culture was strong enough to resist its messages. But television is a portal, and in Bhutan it is systematically replacing one culture with another, skewing the notion of Gross National Happiness, persuading a nation of novice Buddhist consumers to become preoccupied with themselves, rather than searching for their self.

In our Western culture it is only a recent trend introduced by a small elite to see happiness, not material wealth, as society's goal. Here are some of my earlier posts on happiness:

• happiness and new year's resolution (quoting psychologist Martin Seligman)
• on the fate of humanity (quoting economist Richard Layard)