Letters Momentum #29
Momentum Readers Speak Up
Momentum?
This question has bothered me for years. Why when on a long downhill coast, do I always pull away from my wife without any additional effort?
My first explanation was that I weigh more than her. But then I remembered (from physics) that Galileo proved that falling objects fall at the same rate regardless of weight differences. He proved this, not by dropping cannon balls from the Leaning Tower of Pisa, as legend has it, but by rolling objects of different weights down an inclined plane to slow the action down – he did that to “dilute” gravity because he was using his pulse as a timer – he had no accurate timepiece.
I did this experiment myself (with a stopwatch) and verified his results. A bicycle (a rolling weight) running down a hill (an inclined plane) should behave the same way, but my experience proves that it does not. Any idea why the seeming contradiction?
Gene Walker
San Diego, CA
momentum Editor Terry Lowe responds:
I’m no physicist, but Sandy Eix, of Vancouver’s Science World, assured me that Galileo was right: with all other things being equal, two objects of different weight will indeed fall at the same speed.
My thought is that something is unequal between your two bikes, and the first thing I’d look at is the tires. I’ve seen this phenomenon before. Except, in that case, I was the weightier of the two riders, but the other bike coasted down a hill faster. The reason: the other bike’s tires were half the width of mine (and inflated harder), and thus offered much less rolling resistance.
Air resistance – the wind pushing back against you – is also a factor, as may be mechanical resistance of your wheel bearings. A simple and interesting test would be to trade bikes and see what happens.
Shorts Need Filling
This is call out to all creative people in the bike community. My partner and I were recently at the 2007 Bike Shorts film event this year. We were excited to see bikes and bike culture on the big screen.
The evening had a few moments of joyful bikeness but overall was a disappointment. The greatest loss of my time was a film that involved automatic rifles shooting people on bikes. Most of the film was long boring shots of a man cycling slowly through a ghetto. Then in ridiculous Hollywood fashion our protagonist and friends are gunned down.
There was a distinct lack of applause at the end of it. I think almost everyone was glad it was over. I had a burning urge to hiss and boo but was contained by my polite Canadian socialization.
If there is a gap big enough in the roster for a film with firearms and murder then there is simply not enough content. It is up to us to produce it. My request goes out to the cycling community. Please find or create a peaceful bike story and film it.
Dustin Anderson
Wonderful Folks
As a regular reader of your magazine, occasional Critical Masser, sometime photographer and full-time cyclist, I’d like to thank you for your magazine. My only complaint is that it isn’t a monthly publication. I thought you might like these photos. Keep up the good work.
Bruce Twerdy
Fixed Gears are for Jerks
My name is Eric Frame and my band Fixed Gears are for Jerks and Lesbians is coming out to play Queeruption in Vancouver on the 4th of August. We are Minneapolis’ preeminent bike power punk rock band. We like riding bikes and rocking faces off, and if you’re interested, you should come out to Queeruption and check us out. Our contact info is:
Fixed Gears are for Jerks and Lesbians
http://myspace.com/fixedgearsareforjerksandlesbians
Dutch Proofreading
I read your article on the bakfietsen in MOMENTUM, which was nice for me to read as a Dutch citizen. These types of bikes are getting more and more popular in the Netherlands.
I’d like to mention, though, that the singular is “bakfiets”, and the plural is “bakfietsen”. A “fiets” is a bicycle in Dutch.
Sincere greetings from a Dutchman with four “fietsen”,
Erwin de Vries
Leiden, NL
Hi Folks!
Here’s my renewal of a subscription for your fine publication. I’ve been studying the literature of global warming for many years, and over the last year on long bike explorations along the many paths and byways of Southern Vancouver Island, I put together this poem/song which I call “The Slaves In My Garage.” I hope it might shake some folks off the highway of sloth, the home of mobile couch culture.
The Slaves in My Garage
I’m going to buy a sixteen, and ride that asphalt path,
Though the people who make sixteens are very poor at math.
Had they hired Pythagoras, you can bet for bloody sure
They’d all be called a sixteen and not a four-by-four.
I’m going to buy a sixteen or perhaps an SUV,
to protect me from bad drivers who have big cars like me.
But if they switched to bicycles I’m sure I’d buy one too,
To place upon my roof-rack by my motorized canoe.
And I’d really like a sports car so I can exercise;
I’ll drive my muscles to the gym, impress the girls and guys.
From healthy body exercise you’ll never see me shirk,
Unless I find that it involves some kind of useful work.
And I’d love to have an RV and like a hobo roam,
Or better yet a tow truck to pull a mobile home.
I’ll go to all the festivals, camp out on the grass,
Then drive on to the next one in a cloud of “Classical Gas.”
And I’ve got to have a monster truck, to ride amidst the stars,
From my elevated viewpoint look across two billion cars.
Yes, with speed designed for comfort, when I’m wondering what to wear,
I’ll try the many four-wheeled fashions on sale now at Vanity Fair*
[years later]
I’m going to buy a lifeboat. That’s where I’ll make my stand.
Though I don’t really need a lifeboat, I’m going to buy one anyway,
Cause it’s very nice to have one on a hot December day — at the North Pole!
*ref. Pilgrims’s Progress by John Bunyan
David Querido
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