56

This calculation is pretty much worst-case for the bicycle. It doesn't take into account that food production has actually stored CO2 from the atmosphere which is now just released back, while fuel was originally underground and its CO2 is added to the carbon cycle. Neither does it take into account mercury/other emissions, nor the wear-and-tear in cars and ...


47

Many of the frequently quoted statistics don't convincingly show a protective affect from helmets. Cycling is an inherently safe activity where serious accidents are rare. This makes it harder to judge the effectiveness of safety interventions. Small behavioural changes can add significantly to the rate of accidents and confounding factors can easily sway ...


32

The quoted statement says "energy to move a kilometer". On an "energy to move a kilometer" basis, the statement is definitely false. Acccording to Dr. Karen Oberhauser, a tagged monarch butterfly has been confirmed to travel 265 miles in one day. According to How Much Fuel Do Monarchs Burn? reporting Dr. David Gibo's research: On 140 milligrams of ...


23

Based on this paper (thanks to Oliver_C for posting it) you can quite clearly see that their behaviour is understood by physicists (they wrote a paper on it!) To find the essence of bicycle self balance we looked at simpler and simpler dynamical models until we found a minimal two-mass-skate (TMS) bicycle that theory told us should be self-stable. This ...


11

Jobst Brandt, author of "The Bicycle Wheel" (which explains how to build strong bike wheels and which includes a finite-element analysis of spoked wheels) lays out the argument at Sheldon Brown's site: Commercial aircraft, and especially motorcycles, demonstrate that a round cross section tire, like the bicycle tire, has an ideal shape to prevent ...


10

Yes, he did. He admitted this in his interview with Oprah Winfrey. Oprah: Did you ever take banned substances to enhance your cycling performance? Lance: Yes Oprah: Yes or no, was one of those banned substances EPO? Lance: Yes


8

1. Caveat This is going to be an unsatisfactory answer, for the following reasons: Boardman's claim is ambiguous: how are we to interpret the you in "you are statistically more likely to have a head injury walking"? A statistically average person in the country, considered over some period of time such as a year? Someone considering making a particular ...


5

Doesn't seem to be a much studied subject, but there's a study titled Electric Vehicles in China: Emissions and Health Impacts which also claims the emissions from eBikes are ~ 1/10th of those of eCars. As the title suggests, the study is from a whole another field, but there's a section dealing with comparing emission levels from various forms of ...


5

One of the questions raised by several of the commenters was that while one can estimate the calories burned by bicycling, it is hard to estimate what change in calories the cyclist requires (over what would have burned by driving to work). I designed an experiment using a Heart Rate Monitor to help me estimate just that. Notes and assumptions Calories ...


4

This is obviously not true. You have to look at the different materials cars or bicycles are made from because that statement doesn't restrict itself to a specific material. This would require the rubber of 200 bicycle tires to be at most the amount of rubber used to make a car. Most of that rubber is found in the tires of which a car has 5 (let's give it a ...


4

The key source for analysis of risk-adjusting behaviour is the work of John Adams who has long argued that people have a certain tolerance for risk and tend to adjust their behaviour to (partially) compensate for safety devices. In the case of cycle helmets both car drivers and cyclists themselves might take more risks because the cyclist is wearing a helmet....


4

This paper from the Stockholm University estimates the energy used for the production of a good hamburger is 20 MJ (the high estimate) http://www.infra.kth.se/fms/pdf/energyuse.pdf A liter of gasoline contains 35MJ of energy. So two cheeseburgers more per day gives 1L gasoline consumption and a change. Which is usually enough to get 25km in a light car - ...


3

I copied my answer to the Bikes.SE question. Just to add on to what Wilka said about hydroplaning, people involved with the physics of planes landing are particularly interested in hydroplaning. Sheldon Brown of course talks about this. Even with automobiles, actual hydroplaning is very rare. It is a much more real problem for aircraft landing on wet ...


3

It may be difficult to answer this question using statistics. For example, the abstract to the article which rob cites in his answer says, The most frequent accident type among collisions between cyclists and cars at bicycle crossings was a driver turning right and a bicycle coming from the driver's right along a cycle track. This type of accident may be ...


2

Having taken a bicycle safety course, I can attest to part of the syllabus in which they explain why bicycle lanes are less safe than operating as another road user / vehicle operator. As a proponent of these courses, I operated in that manner and have personal experience for both methods. Bicycle lanes are unsafe compared to conventional road operations. ...


2

No, there are no laws, and no planned laws, for cyclists in New South Wales to pay registration. Since posting this question, it was discussed in the Parliament of NSW. Registration was "ruled out" by the Minister for Roads, Duncan Gay. Here is an excerpt, culling out some of the political nonsense: The Hon. PENNY SHARPE ( 15:18 ): I direct my question ...


2

Doing a Google (Australia) search for "bike riders will now have to carry photo id and pay rego", you find the SMH announcement of a proposal from Jul 15, 2015, and more reports around Dec 21, 2015, that it is intended to be a law passed in NSW State parliament, to start March 2016 and enforced with fines March 2017. In fact, you'll also find "Bicycle ...


2

Not much research has been done into this topic, although the statistics published in the State of Idaho Highway Safety Plan, Fiscal Years 1981-1984 where used in an open letter by Jason N. Meggs to argue the following point: There is no evidence of any long-term change in injury or fatality rates as a result of the adoption of the original Idaho Law in ...


2

It seems legit. LiveStrong and the BBC both reference a 2009 Cordoba study. I believe those are talking about "Sperm morphology normalcy is inversely correlated to cycling kilometers in elite triathletes" which concludes: The main finding of the present study is that cycling training volume inversely correlates to sperm morphology. That is, athletes ...


1

Cyclists will warn you that although you won't actually hydroplane, nevertheless you have less traction on wet surfaces: and that some surfaces (painted lines, and metal man-hole covers and streetcar rails) are especially slippery. Tire manufacturers acknowledge/allege this (loss of traction), and produce tires designed to improve wet-weather traction, for ...


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