Reports of the demise of this Web site are greatly exaggerated! We at thank Harris Cyclery for its support over the years. Harris Cyclery has closed, but we keep going. Keep visiting the site for new and updated articles, and news about possible new affilations.

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by Sheldon "What, Me Worry?" Brown
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Re: CO2 tire inflators 1997/02/15

redmist wrote:
> As far as weight and efficiency go these seem to be the way to go vs. frame
> or mini pumps. Any drawbacks?

CO2 is heavier than air, you will make your bike heavy and slow if you
use it.  Helium is lighter, the only way to go if you want speed and

If you are willing to live dangerously, Hydrogen is lighter and cheaper
than Helium, but don't smoke while riding your bike if you use

Carapace Completed Umber
Lakehurst, New Jersey
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Re: Riding while pregnant

rec.bicycles.misc 1997/02/01

Rafael Aviles wrote:
> Riding while pregnant is not too difficult. Getting pregnant while riding is,
> of course, a bit trickier...

My buddy, John Allen ( used to
that this might be possible on a recumbent tandem...and that one might
be able
to finance it by getting funding for "recumbent dna research."

Carapace Completed Umber
Reno, Nevada
|  I'm only a beer teetotaller, not a champagne teetotaller.  |
|                               --George Bernard Shaw         |
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Re: WTB:Bike Training Software for Macintosh

rec.bicycles.marketplace,rec.bicycles.soc,rec.bicycles.rides,rec.bicycles.misc 1997/01/28

I don't need it, my bikes are all _perfectly_ trained!

Carapace Completed Umber
Cupertino, California
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Re: A Velodrome run by a dairy?

rec.bicycles.misc 1997/01/16

Jessica Mosher wrote:
> Okay, I'm did a dairy end up running a velodrome?
> Or was the velodrome there first, and just on the land that was
> later developed into a dairy? 

This place is a legend in track circles!

In addition to the normal events, each program ends with a special
race where the cyclists must outrace an angry bull.  This is a 
real crowd pleaser, as you would imagine.

It is not well known, but this is where disc wheels originated, 
because when a bull gets his horns into your spokes, you are dead
meat, but with a disc wheel, the horn just glances off, and you 
can save yourself if you have a good sprint.

Carapace Completed Umber
Valencia, España
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Re: helmets and death

rec.bicycles.soc 1996/12/12

burke wrote:
> Garry Lee ( wrote:
> > Forget it.
> > This argument has gone on for years and will not stop.
> > You'll achieve nothing.
> > This is the official end of this thread.
> > Unless it isn't.....
> I agree.  Your post was the last one.

Well, That's a relief!

Carapace Completed Umber
Aristarchus, Luna
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Re: Opinions on Spinergys


Jobst Brandt wrote:
>...the Spinergy wheel...relies on its pretension to support the rim...

Does this mean that those who ride Spinergies are pretentious?  I've
often suspected that...

Carapace Completed Umber
Hoople, N.D.
|      Certainly the game is rigged.           |
|        Don't let that stop you;              |
|     if you don't bet, you can't win.         |   
|                   --Robert A. Heinlein       |
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Re: Fixed Gear Advantages?

rec.bicycles.misc 1997/07/11

> I wrote:
> >I have a Web article which expatiates at some length on this subject:
> >
> >Sheldon "The Bottom Line Is FUN!" Brown
> >Newtonville, Massachusetts

Rich Haubert responded:

> Hey, Sheldon!  Do you happen to have a web site that covers any
> bicycling
> topics?   If you do, you sure keep quiet about it!  : )   : )'s a secret!

Carapace Completed Umber
Somewhere in Cyberspace
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Re: A spinning wheel is stronger? 1996/10/14

Matthew Tovey wrote:
> I read recently that a bicycle wheel is significantly stronger while
> spinning than when stationary.
> Any bicycling physicists want to give their opinion on this? :)

This is certainly true. The centrifugal force expands the 
rim and this makes the spokes get tighter.  Everybody knows 

Carapace Completed Umber
|      And you are right, and I am right       | 
|       and everything is quite correct        |
|               --W.S. Gilbert                 |
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Re: Neuron Tubing

rec.bicycles.misc, 1996/10/01

Denis Drew wrote:
> In <> Jack Dingler (
> writes:
> >Now how about getting rid of all these senseless helmet args....
> Sorry; I'm too busy writing prolife arguments.  :-)
I've got a pair of Prolife aero bars, I like 'em ok, and they are a good 
place to carry my helmet...

Carapace Completed Umber, 

Neuronville, Massachusetts
|   It is my considered opinion that    |
|   the state of New Hampshire is       |
|   not yet ready for self-government.  |
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Re: Warm Hands and Toes...

rec.bicycles.misc 1996/11/14

Deb Lowe wrote:
> Once again I've reached that time of year when I desparately
> searching for ideas on how to keep hands and feet warm in
> sub-freezing temps.  Any new products (advances in cold
> weather-proofing): booties, gloves, etc.

I find that the combination of oil-fired hot air, a heated waterbed
and a down comforter works great for me!  YMMV...

Carapace Completed Umber 
Tahiti, French Polynesia
|  I don't believe in astrology. But then I'm an Aquarius,  | 
|  and Aquarians don't believe in astrology.                |
|                                     --James R. F. Quirk   |
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Re: Why straight fork ? 1997/05/07

Eric Harvey wrote:
> 1) Coloured tires stick so much better when riding fast through curves,
> provided one wipes them off after riding through debris.

This is a gross oversimplification of a very complicated and arcane
subject.  Actually, green or blue tires are better for cornering, while
red or orange are faster on the straighaway.  For serious off-road
riding, especially in the springtime, all the pros use brown tires.

Contrary to what you might expect, white tires are lousy in snow.

> 2) I can ride faster through curves if I put my cranks on with bone-dry
> tapers.

Hey, children sometimes read this NG, easy on those multiple entendres!

> 3) Tying and soldering the spokes in my  wheels allows a faster speed
> through curves.

This goes without saying, everybody knows that!

> 4) Deflating my tubulars after riding them will allow me to ride faster
> through curves the next time.

No,No NO!  This is an old husband's tale!  

Just as training at high altitudes improves your oxygen uptake capacity
for riding in the lowlands, you should pump your tubulars up 20-30 psi
(13.605-2.041 bar) _over_ their normal pressure for storage.  This will
get them acclimated to high pressure.  When you let the excess air out
to actually ride on them, they will be livelier and faster!

Carapace Completed Umber
Liège, Belgium
|  When I was in school, I cheated on my metaphysics exam: |
|  I looked into the soul of the boy sitting next to me.   |
|                                          --Woody Allen   |
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Re: I was hit by a deer

rec.bicycles.rides,rec.bicycles.misc 1997/02/03

Jobst Brandt wrote:
> Well, I ran into a grizzly bear and had do beat on his nose with my
> tire pump to drive him away.  He got a claw caught in my front wheel
> and ripped out a couple of spokes as he turned to escape my withering
> attack.  The deep snow made the whole scene surreal as powder flew in
> all directions like fog.  Fortunately I was riding dual knobbies for
> deep snow traction, as we often do in the frozen north, and continued
> to a nearby trappers cabin.  Wow!

If it weren't for the fact that you were riding a dual-suspension 
bike, you would've been dead meat!

Good thing you didn't rely on a Quikfil for that ride.

Carapace Completed Umber,
Prudhoe Bay, Alaska
|  There are strange things done in the midnight sun,  | 
|  by the men who moil for gold,                       |
|  The Arctic trails have their secret tales,          |
|  That would make your blood run cold...              |
|                                  --Robert Service    |
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Re: Tying & Soldering Spokes 1997/01/18

Jobst Brandt wrote:
> John Lee writes:
> > I have also said that his theory does not include all of the nuances
> > entailed in building wheels for specific customers.
> I would like to hear some of these.  This remark has come to my
> attention a few times since the book was first reviewed in Bicycling
> Magazine, where it first appeared.  None of these critics has offered
> any of the aspects of wheel building that were left out.  Maybe you
> can.

Oh, Jobst, you're _so_ narrowminded!  

It really is important to tailor wheelbuilding techniques to the 
different needs of different kinds of riders.  For example:

I find that some of my wheel-building customers want me to build 
them wheels that are bombproof, but still as light as a possible.

Then again, there are others who want just exactly the opposite: 
wheels that are as light as a possible, but still bombproof.

In either case, I use well-known mechanical and scientific principles
to build wheels that combine the desired qualities.

Carapace Completed Umber
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Re: mail order wheels

rec.bicycles.misc 1996/08/04

Jobst Brandt wrote:
> Michael Palmer writes:
> > Just got a rear wheel from Performance (XT, 217) with the rim
> > "backwards."  I use scare quotes around backwards because I suppose
> > it is only convention which dictates that the rim label is readable
> > from the drive side.
> That is about as important as the even more arcane "rule" that the
> manufacturers name (Campagnolo) be in line of sight when the hub is
> viewed through the valve stem hole.  Since I remove the labels before
> building a wheel rule #1 vanishes.
Wellll...if you build your bike with old Campag hubs this way, and you 
hang it up, the weight of the valve will make the wheels end up so that
the oil hole is on top!

The most important thing to remember in building a wheel is to lace it
so that the label on the rim is opposite the valve hole.  _All_ good 
wheelbuilders do this. 

Carapace Completed Umber
|     You can go wrong by being too skeptical      |
|       as readily as by being too trusting.       |
|                         --Robert A. Heinlein     |
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Re: Jobst Attitude 1996/04/09

David Casseres ( wrote:
: In article <4k3cbg$>, (Chris
: Rutkowski) wrote:

: > I don't always agree with what Jobst says, but I certainly respect his
: > integrity. Jobst makes a real effort to increase our collective store
: > of knowledge. Critics and carpers are a dime a dozen..

: I second that.  Jobst does seem to bring out the critics and carpers at
: discount rates, though.  I think if Jobst were to post that water boild at
: 100 degrees Celsius, three or four people would reply that Jobst is an
: idiot because everybody knows water freezes at 32 degrees Fahrenheit.  And
: we'd be off and running again.

The above is absolutely false.  The fact is that water _thaws_ at 32 degrees
Fahrenheit.  How wrong canya be!

Carapace Completed Umber
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Re: Which side QR? 1995/12/12

Earle Young <102346.2614@CompuServe.COM> wrote:
>Tradition is that the skewer is on teh left side of the bike as 
>you sit on it, so that a right-handed mechanic can quickly 
>release it.
>although I have also read, long ago in the late lamented Bike 
>World magazine, that putting it on the right side breaks the wind 
>a little bit for the derailleurs. Neat theory, but I say bogus.

Naw, it is 'cause the chain and derailers are on the right side, 
so the bike is unbalanced.  Putting the quick-release on the left
helps balance the bike better.

For this reason, it is a mistake to buy lightweight quick releases, 
because they don't weigh enough to counterbalance the chain and 
derailers, so the bike goes in circles when it should go straight.

If you put the quick-release on the right side, i.e., the wrong side,
you will certainly crash.

Carapace Completed Umber
Procyon IV
|  But though I felt some concern, even some guilt,  |
|  what I felt mainly was reverential excitement.    |
|                                     --John Barth   |
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Re: Help...T_Wheel removal 1996/11/17

Jane Selin wrote:
> Howdy,,,from the shores of the beautiful Hudson River.
>      Four years ago I bought a very nice MTB (Rock Lobster). I used my
> Public assistance income(Welfare) for this purpose. It's funny how owning
> and riding a $2000.00+ bicycle has brought dignity and in turn good
> fortune into a dark hopeless existence that I had shared with so many.
>     Enough of the biking baglady already.................
> ...............The Question Please.........OK then..............
> ..........I had custom training wheels put on my bike. They were hand
> crafted with Tange MTB tubing. The builder welded them to the chain
> stays and ran additional supports to the seat stays. It cost a
> bunch,,,,,,,,,,I mean, I had to really cut back on restaurants and
> movies, and even go without a good lighting system for a few
> months..............So.....I want to get these things off my bike as
> cheaply as possible without ruining me Rock Lobster.
>    Any suggestions will be most welcome.
> Thank you very much indeed!
> Jane

My dear Ms. Selin, we must protest your shocking waste of bandwidth.  

The ellipsis (...) is, perhaps, our second favorite punctuation mark to
abuse (after the semicolon).  However, the ellipsis, properly constructed,
consists of a mere three periods (or, as 'Net geeks call them "dots"),
unless it follows a complete sentence, in which four are permitted. 
In your otherwise valuable message, you have consumed 69 unnecessary (.)s.  

This amounts to 552 (1000101010) wasted bytes!  In addition, after the
word "bunch" you have used ten (10!) commas, in lieu of a proper ellipsis.
This is an unforgiveable solecism...for shame!

While we realize that those of your unfortunate social class have not 
had the benefits of a proper education, it would, perhpaps, be wiser, in
future, to leave this newsgroup to your betters, who know how to use it

As ever, Yr. Humble, Ob'dt, Svt.,

Carapace Completed Umber, Esq.
|   This message has been sent to you using recycled electrons    |
|       exclusively.  Please do not discard them after use,       |
|     send them along and help conserve these irreplacceable      |
|           sub-atomic resources for future generations.          |
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Re: Saving Somewhat-Stripped Cranks 1996/03/09


Jobst Brandt wrote:
> Ed Davis writes:
> >> Its the broaching effect of the crank/spindle interface that limits
> >> this to some finite number that usually doesn't affect the useful life
> >> of the crank.  Grease the spindle before installing, torque it to the
> >> prescribed torque and don't mess with it until you remove it again.
> > GREASE THE SPINDLE ? What are you smoking ?
> > Maybe I am wrong, but are you saying grease the four flat sides??
> > DON'T DO IT!
> Oh!  Why not?  That's another bugaboo that keeps getting passed
> around, especially now that there are so many aftermarket cranks
> designed by non engineers and whose cranks are wimpy to be lighter
> than the next guy's.  They have other failures but want to pass it on
> to the "no grease" story.
> > The proper way to put a crank on is clean it completely with grease
> > remover, and also the crank. Then swab all surfaces with isopropyl
> > alcohol. Use a Q-Tip and be a perfectionist.  use two q-tips per
> > surface. That's two cotton swab ends loaded with alcohol, and two
> > dry ones to rub off the swill. Get those surfaces spanking clean
> > with ZERO contaminants.  Then slip crank over spindle, tighten to
> > proper torque plus 1/8 turn, pull crank back off 1/8" inch, then
> > tighten to exact torque again. if you grease the spindle your cranks
> > will end up creaking and will eventually splay.
Youse guys are all full of used food!  

The proper way to install cotterless cranks is to clean the tapers as Ed
says, then put grease on two of them, leaving the other two clean.  

Incompetent nincompoops grease opposite sides, but all good mechanics
grease the two adjacent sides that are on the bottom when the crank 
is in the forward position.  If you don't do this, your crank will break
off, and you may also have problems with your bicycle.

Carapace Completed Umber
forwarded from
|  ...Which two mighty powers powers have...been engaged in a most   |
|  obstinate war for six and thirty moons past.  It began upon the   |
|  following occasion.  It is allowed on all hands, that the         |
|  primitive way of breaking eggs before we eat them, was upon the   |
|  large end; but his present Majesty's grandfather, while he was a  |
|  boy, going to eat an egg, and breaking it according to the        |
|  ancient practice, happened to cut one of his fingers.  Whereupon  |
|  the Emperor his father published an edict, commanding all his     |
|  subjects, upon great penalties, to break the smaller end of their |
|  eggs.  The people so highly resented this law, that our histories |
|  tell us there have been six rebellions raised on that account;    |
|  wherein one Emperor lost his life, and another his crown...It is  |
|  computed, that eleven thousand persons have...suffered death,     |
|  rather than submit to break their eggs at the smaller end.  Many  |
|  hundred large volumes have been published upon this controversy...| 
|                                                 --Jonathan Swift   |
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Fractional Cogs? 1999/9/15

[name deleted to protect the innocent] wrote:

Just a couple of New-B-Q's while planning a new cassette.
> 1.  Does the tooth-count really directly correspond to the diameter of the
> cog?

Yes, as long as the distance between teeth is the same.  The critical
dimension is from the center-to-center of the bottom curves.  This
corresponds to the distance between the centers of the chain rollers.

> 2.  Has anyone ever tried cogs with slightly "off" diameters in order to
> smooth the percentage change between shifts?  I would think that it would be
> possible to engineer cogs which are up to say 30% out of tooth-count size by
> varying tooth depth and angles of entry/exit without any loss of
> transmission.  In conventional terminology, one might end with something
> like
> 12.0--13.2--14.4--15.8--17.3--19.0--20.8--22.8--25.0
> If this hasn't been shown to be impracticable, why doesn't someone do it?

I've proposed this in the past, but have met with a stonewall response
from the narrowminded mossbacks who run the bike industry.  I used to
think they were just too stupid to appreciate the value of this system,
but have since learned that it is not that simple (nor that benign!)

The industry giants Campagnolo and Shimano purportedly "compete" against
one another, but this is all a fraud.  They actually have divided up the
industry into hegemonic spheres of interest, and divide the whole pie
bewteen themselves.  

These people are secretly in the pay of the Tri-Lateral Commission, OPEC
and the Detroit and Osaka automobile cartel.  They have been
deliberately sitting on this technology, in order to protect the
financial interests of their internally-combusting masters.  

They know full well that if the general public had the opportunity to
buy bicycles with gears as well spaced as your example, motorists would
abandon their eternal-consumption smog cages in the millions.  

I'd suggest watching your back very carefully...these guys pay for
keeps, and previous posters who have proposed similar technologes have
been abruptly silenced.  I would advise that if you _do_ post on this
topic again, that you use a pseudonym so they won't be able to get you.

Carapace Completed Umber
Kent, Washington
|       I saw a man pursuing the horizon;       | 
|       Round and round they sped.              | 
|       I was disturbed at this;                | 
|       I accosted the man.                     | 
|                                               | 
|       "It is futile," I said,                 | 
|       "You can never--"                       | 
|                                               |
|       "You lie," he cried,                    |
|       And ran on.                             |
|                    --Stephen Crane            |
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Re: Pace, Bomber's, or Rock Shox?, alt.mountain-bike 4/12/2000

Corvus Corvax wrote:
> "Steven McGuinnity" explains why gas has stiction:
> > However inside a suspension fork (basically a piston) the gas is under
> > pressure and has nowhere to be displaced to. The property of a gas
> > "similar to surface tension in liquids" is the work required to
> > compress the gas, more specifically the work required to overcome the
> > static friction and start the compression of the gas. Once the static
> > friction has been overcome the compression is far more smooth as
> > dynamic friction is always less than
> > static friction. You would be perfectly correct if it was a 'ideal'
> > gas however we live in the real world where things tend to be a bit
> > more complex. Later,
> Quite correct. Gaseous stiction is something that few people in the bike
> industry have the sophistication to recognize, but it's a very important
> design consideration. One way to get around it would be to use an ideal
> gas such as helium or argon, but the expense would of course be
> prohibitive.
> In fact, using non-ideal gases in compression forks can create a number
> of nasty problems, the most insidious of which is "gas-phase
> hysteresis", basically a form of energy storage in the rotational and
> vibrational modes of the molecules in the gas. Essentially, every time
> the fork compresses, there are small losses from the gas pressure to
> these other modes, sort of like compressing an elastomer and having it
> not spring back quite all the way. Over time, hysteresis effects can
> build up and give the fork a syrupy or overdamped feel. In extreme cases
> it can even damage the piston. The solution (and I'm amazed at how few
> air shock owners know this) is to bleed the shocks periodically and
> refill them with fresh air.
> Some people just don't listen, do they?

I get so sick and tired of scientists and engineers from outside the
bicycle industry taking a patronizing, know-it-all attitude, and
concluding that the people who design bikes are a bunch of doofi who
don't know their fundaments from their arm joints.

All of the reputable makers of air-sprung forks are well aware of the
air stiction problem, and their designs take it into acount.  The
correct amount of air congelation is an essential parameter in the fork
design. Failure to pre-treat the air will, to be sure, will cause
insufficient damping.  The advice to bleed the fork deliberately and add
fresh, un-treated air, is dangerous and irresponsible.  Use of fresh,
un-treated air will certainly cause insufficient damping, probably
leading to injury or death!

If Dr. Corvax would come down from his ivory tower and visit a shock
fork manufacturing facility, he would see the rows upon rows of
reciprocating fork stressing machines noisily pre-treating the air in
new forks prior to shipment.  

These machines, similar to the machines used to mix paint, are an
essential tool.  Any real mechanic who works on air-sprung forks will
have one or two of these machines next to his workbench.  

Most use the relatively cheap ($350 retail) Park FAC-1 fork
pre-compressor, others prefer the somewhat more expensive ($475) Bicycle
Research FP3.  Each does an equally good job, but the Bicycle Research
FP3 runs a bit more quietly. 

Since I try to avoid reliance on power tools, so I use a human-powered
unit of my own design, based on the chassis of a Tunturi Ergometer.  I
have this set up in front of my computer, so I can be getting a workout
and also pre-treating a customer's fork at the same time I am writing
valuable and useful postings about the vote count in Florida for

Carapace Completed Umber
Magdeburg, Germany
| Westheimer's Discovery:                                |
|   A couple of months in the laboratory can frequently  |
|   save a couple of hours in the library.               |
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More Bicycle Humor

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Articles by Sheldon Brown and Others

Reports of the demise of this Web site are greatly exaggerated! We at thank Harris Cyclery for its support over the years. Harris Cyclery has closed, but we keep going. Keep visiting the site for new and updated articles, and news about possible new affilations.

Copyright © 1998, 2008 Sheldon Brown

Harris Cyclery Home Page

If you would like to make a link or bookmark to this page, the URL is:

Last Updated: by Harriet Fell