HUMAN POWER · 2010. 11. 18. · Dietrich Fellenz, an alert reader, found some errors in this piece from the vol. 12 no. 4 issue. The author, Tim Gorman, col-laborated in providing

HUMAN POWERVolume 13 Number 1 Fall 1997 $5.00: Members, $3.50

HUMAN POWERis the technical journal of the InternationalHuman Powered Vehicle AssociationVolume 13 Number 1, Fall 1997EditorDavid Gordon Wilson21 Winthrop StreetWinchester, MA 01890-2851 [email protected] editorsToshio Kataoka, Japan1-7-2-818 Hiranomiya-MachiHirano-ku, Osaka-shi, Japan [email protected] Schmidt, EuropeOrtbiihlweg 44CH-3612 Steffisburg, [email protected] Thiel, watercraft4720 - 7th Avenue, NESeattle, WA 98105 USAProductionJS DesignDavis, CaliforniaIHPVA1308 Broad Street, #72San Luis Obispo, CA 93401 USAPhone/fax: 805-466-8010Board membersTim Brummer, Marti DailyMurray Dowling, Bill GainesAl Krause, Chet KyleAndrew Letton, Gardner MartinChristian MeyerOfficersPaul MacCready, international presidentCarole Leone, presidentJean Seay, executive vice presidentChris Roper, vice president, airMatteo Martignoni, vice president,

all terrainTheo Schmidt, vice president, hybrid powerAndrew Letton, vice president, landJim Richardson, vice president, submarineNancy Sanford, vice president, water

Human Power (ISSN 0898-6908) ispublished irregularly, ideally quarterly, bythe International Human Powered VehicleAssociation, a non-profit organizationdedicated to promoting improvement,innovation and creativity in the use ofhuman power generally, and especially inthe design and development of human-powered vehicles.

Material in Human Power is copyrightedby the IHPVA. Unless copyrighted also bythe author(s), complete articles orrepresentative excerpts may be publishedelsewhere if full credit is given prominentlyto the author(s) and the IHPVA.

CONTENTSRiding a boat like bicycle

David Witt reports on a remarkableseries of single-hull boats that he and hisOxford-university students have built. Whenstationary they are as unstable as arebicycles. When underway and steered by aforward rudder they can be directed "undera fall" and have bicycle-like stability. He alsoanswers the predictable question "Why aren'tthey like recumbent bicycles?"A composite-propeller-blade manufac-turing process for HP water vehicles

Leo Benetti-Longhini and Bradley Klenadescribe and illustrate their CAD-CAMmethod for molding HPB propellers fromcarbon-fiber-epoxy.Twenty-four hours in Koln

Your editor was lucky enough to spend aday at the well-organized InternationalHuman-Powered Speed Championships inKo1n in August 1997, and photographed andmade notes on some of the technology andthe people there.Low-cost aerodynamic testing

Dominic Bencivenga wanted to share hispassion for vehicle racing with his high-school class, while teaching them some prac-tical skills. He adapted a method ofaerodynamic testing that requires students todesign HPV streamlined bodies, to manufac-ture them to a specified cross-section, tomount them on a standard wheeled chassis,and to determine their relative aerodynamicdrag by allowing them to be rolled backwardsby a simple fan-produced nozzle flow.Correction to "Steering-trailing-arm-angle determination"

Dietrich Fellenz, an alert reader, foundsome errors in this piece from the vol. 12no. 4 issue. The author, Tim Gorman, col-laborated in providing corrections.Low, high and foldable: The Wave

An article by Marga A. B. Ruitenbeek,from HPVNieuws, translated from theDutch by Wouter Suverkropp.

ReviewsThe comprehensive, superbly made CD-

ROM of Oliver Zechlin and his team; aCoroplast-fairing seminar by Ed Gin andPeople Movers; and videos on fiber-glassing,mold construction, vacuum-bagging and thelike by Fibre Glast Inc. The proceedings ofthe Seventh International Cycle-HistoryConference turned out to have much ofinterest to HPV people: you will read aboutdicycles, and perhaps learn with surprise howsmall are the losses in derailleur gears.Letters

Lowell Zabel comments on Tim Gorman'sarticle; William Volk suggests HPVs as"Dodgem cars" at fun-fairs; Joachim Fuchsdisagrees in some respects with our favorablereview of the Tour article on wind-tunneltests of traditional and recumbent bicycles;Paul MacCready, IHPVA international presi-dent, compliments HP; John Riley com-ments on an editorial view on some ridersand bicycles being slow on hills; and ArnfriedSchmitz, an enthusiast for and historian ofHPVs living in France gives us a "mini-histo-ry" of HPVs from a new perspective;Notes

David Conn reports on a conference heattended in Vancouver, Canada, put on bythe Organization for Economic Cooperationand Development. The small concern forhuman-powered transportation he foundthere leads him to encourage us to attendmore such transportation conferences torepresent our views. Chris Juden and MarkMarsh report on sometimes-explosive failureof aluminum rims. Zach Kaplan adds hisviewpoint about riding with fairings to thatof John Tetz (HP vol. 12/4). A call forpapers for a symposium in Denmark in1998 and an article from the Netherlandsabout bicycles and taxes rounds out thissection.Editorials

The outing of impotence (Dave Wilson);Record rules and altitude (a guest editorial byPaul Buttemer of Canada).

2 Volume 43 number •1, fall 1997 Human Power

CONTRIBUTIONS TO HUMAN POWERThe editor and associate editors (you may choose with whom to correspond) welcome contri-butions to Human Power. They should be of long-term technical interest (notices and reports ofmeetings, results of races and record attempts, and articles in the style of "The building of myHPV" should be sent to HPVNews). Contributions should also be understandable by anyEnglish-speaker in any part of the world: units should be in S.I. (with local units optional), andthe use of local expressions such as "two-by-fours" should be either avoided or explained. Askthe editor for the contributor's guide. Many contributions are sent out for review by specialists.Alas! We are poor and cannot pay for contributions. They are, however, extremely valuable forthe growth of the human-power movement. Contributions include papers, articles, reviews andletters. We welcome all types of contributions, from IHPVA members and nonmembers.

2 Volume 13 number , fall 1997 Human Power

* The art of moldless composites

(The five videos plus the set of backupbooklets and shipping cost me $162.85).

I bought the whole collection of videosput out by Fibre Glast, together with all thebackup booklets, after someone wrote incomplimentary terms about one of thevideos on the HPV e-mail network. They alllived up to the advanced billing. They areprofessionally produced, shorter and crisperthan the Coroplast video reviewed above(and more expensive), and they introducethe viewer to more-professional methods ofmaking high-quality fairings. All the videosare introduced by Marilyn Klein, owner andCEO of Fibre Glast, and demonstratedprincipally by Scott Campbell, marketingdirector, who shares the narration with hisboss. I have been making fiberglass partsand fairings for many years, and I havenever been very proud of the results. Thesevideos showed me why. The degree of carerequired and attention to detail were wellillustrated. The techniques were shown inclose-up and fully explained. I particularlyenjoyed the video on vacuum-bagging andsandwich-core construction, but I wouldimagine that everyone except an establishedexpert would learn a great deal from any ofthe videos and especially from the set. AfterJohn Tetz's article in HP 12/4 on his fairedHPV in which he mentioned using a mold-less technique in making the fairing, therewere several inquiries on how he did it.One of the videos gives the answer!

The presentation is friendly and low-key:the company's products were not promotedunduly. There was also an emphasis on safepractices, on wearing masks and gloves. Onthe other hand, one video was made as anexchange with a college making a super-mileage vehicle: Fibre Glast supplied ScottCampbell and materials and was allowed tovideotape the whole procedure. I applaudedthe honesty with which Campbell showedhow the techniques were improved duringthe project. What worried me was the waythe students put on gloves which they usedto scratch any itch that developed on anybare skin, and the way their arms becamecovered with epoxy. That was how I becameseverely allergic to epoxy (during a three-week all-out effort to develop some innova-tive pumps), with the result that now I oftenhave to be hospitalized after getting a littlehardener on my skin. Be warned! Otherthan this criticism, this is a highly educa-

tional and valuable set of videos, stronglyrecommended.

PROCEEDINGS OF THESEVENTH INTERNATIONAL CYCLE-HISTORY CONFERENCEReviewed by Dave Wilson

The international cycle-history confer-ences were started in 1990 in Glasgow,when Nick Clayton, editor of TheBoneshaker, the journal of what is now theVeteran-Cycle Club, invited people interest-ed in cycle history to commemorate thesupposed 150th anniversary of the firstknown pedalled bicycle, that of KirkpatrickMacmillan in Dumfries, Scotland. (It was asuitable starting point, because little isknown of Macmillan or his bicycle, or of itsexact year of completion. Most historical"facts" about cycle history have turned outto be almost equally uncertain). Rob van derPlas has edited and handsomely published,through Bicycle Books (1282 7th Avenue,San Francisco CA 94122 USA) andMotorbooks International, the fourth(Boston) through the seventh (Buffalo) pro-ceedings. They are excellent value at $30and $45 (the price alternates) plus postage,hardbound. (This vlume is $45 plus ship-ping.) As this issue of Human Power goes topress the eighth conference should be meet-ing, again in Glasgow, Scotland, and wehope that Rob van der Plas will again bringthe proceedings to us.

There are two views of the wisdom ofstudying the history of a topic before tryingto develop something innovative. One isthat knowledge about what others havedone or attempted to do somehow limitsone's creativity. The other view, attributed tovarious people, is that those who ignore his-tory are condemned to repeat it. I endorsethe latter view, having designed or helped inthe development of several recumbent bicy-cles that turned out to have similarities withprevious machines. At the time I had takenvirtually no interest in cycle history. Anotherstatement that is always true is that greatinventors, scientists and others stand on theshoulders of giants. Some people acknowl-edge the prior giants; others pretend thatthey made a huge leap on their own. Itirritates me when Edison is credited withinventing the electric light bulb, when infact he took the carbon-filament bulb overfrom Joseph Swan of my home town ofBirmingham, England. Some believe that

the great Einstein owed a great deal of hisrelativity theory to his wife, whom he didn'tacknowledge, in addition to the several menwhom he did. I am regularly sent draft con-tributions for Human Power on topics ordevelopments that have been well coveredbefore. I return them, asking the authors torefer to the previous work and to point outthe improvements that have been made.(The contributions are seldom resubmitted).

My purpose in this preamble is toencourage you to read, or at least to scan,this volume and its predecessors for yourself.I will, however, attempt a short summary ofthose papers that I believe will be of especialinterest to Human Power readers.

Dicycling Down the Decadesby Roger Street

"Dicycle" was the name that came to begiven to a two-wheeled vehicle in which thewheels are parallel and co-axial, (the illustra-tion is from Sharp) usually with the rider(s)striding with a form of yoke around thechest or, for pedalled machines, sitting on aseat that may have the rider's center of gravi-ty below or above the wheel axis. (Thewheels were therefore usually over twometres diameter.) I have never taken dicyclesseriously: I have never seen one, and theyare not given much space in either of thetwo nineteenth-century books on which Irely most. Roger Street's eight-page papershows that dicycles were, in fact, earnestattempts at providing improved, safer, loco-motion, first appearing apparently in Britainafter Karl von Drais introduced the first

bicycle as a "running machine", and later inthe U.S. and Britain with pedals after theFrench velocipede developments in the1860s. Speeds of up to 9 m/s (20 mph) overa measured mile were claimed even for theearly foot-propelled models, and long tripsat reasonable speeds for the pedalled ver-sions. These co-existed with "ordinaries" orhigh-wheelers, the dangers of head-first"croppers" from which were well known.One could not "come a cropper" with adicycle, although I would imagine that ifone wheel encountered something that sud-denly slowed it during a high-speed descentthe result could be exciting.H. Cadot and hisRelevance to Bicycle Historyby David Herlihy

"True" historians are detectives, siftingthrough murky evidence to find out who

16 Volume 13 number 1, fall 1997 Human Power

16 Volume 13 number 1, fall 1997 Human Power

did what and when. (Most people who tryto popularize history are "recyclers", usingothers' work, all-too-often inaccurately.)David Herlihy is a Boston-area historianwho has been engaged for several years inwhat I have found to be an exciting searchfor the origins of the French velocipede. Hebelieves that Pierre Lallement was the inven-

tor, and that others copied him and thenclaimed credit. (Herlihy has thus annoyedsome guardians of the old order.) This paperabout a velocipede builder from Lyon addsintriguing evidence to the puzzle. Herlihyties the Olivier brothers, two behind-the-scenes well-to-do collaborators with Pierre

Michaux, who is usually given credit fororiginating the velocipede, with Lallementand Cadot. It is almost cloak-and-daggerwork, and good reading.

Who Invented the Penny Farthing?by Nick Clayton

This is either a leg-pulling or a deliber-ately provocative title, because most cyclehistorians have a passionate objection to theuse of the term "penny-farthing" to identifythe ordinary or high bicycle. (It is reckonedto be a derisive term used by Londonurchins long after the heyday of the high-wheeler.) Nick Clayton starts by pointingout that some long-standing mysteries ofcycling history have been resolved, and citesthe acknowledgment that Von Drais was themaker of the first two-wheeled machine and

that the supposed inventions of the Comptede Sivrac were pure myth, along with theperson himself. Clayton said that he wastold in 1980 that no one would ever knowwho started the development of the veloci-pede into the high-wheeler, and that hespent sixteen years trying to disprove thisstatement. He examined 24 histories, ofwhich nine stated that a M. Magee of Pariswas responsible, while eight credited JamesStarley of Coventry, UK. A fascinatingaccount of his researches leads to the con-

clusion that an early misprint, coupled withmany writers of history (perhaps of the"recycling" type) repeating the misprintwithout checking, gave Meyer as Magee.Studying reports of bicycle races inBirmingham and Wolverhampton, UK,Clayton found that all the winners in April1870 were riding "boneshakers with wheelsunder one metre in diameter", while byOctober the winners were using machineswith wheels around 25% larger. He then

found that the leading racer of the day,James Moore of Paris, wrote in 1931 that"in the early summer of 1870, I was riding a

43" Meyer tension-wheel bicycle and usedtoe-pedals, whilst my opponents were yetpedalling from the instep on Phantom 36"wheels which enabled me to overlap myopponents". Someone many years ago sentme a copy of a page containing a sketch of atension wheel by Sir George Carley, whowas trying to build aircraft in the early nine-teenth century, so that Eugene Meyer prob-ably did not invent the tension wheel itself.But it now seems very likely that he devel-oped the metal wheel (Cayley's seemed to bewood and rope) and thereby led bicyclesfrom heavy, slow "boneshakers" to light, fastexciting steeds.

Derailleur Pulley Resistanceby Ron Shepherd

Ron Shepherd is a professor of engineer-ing at Melbourne University, Australia. Hegives a short but interesting history of thederailleur gear, mentions briefly his students'work on the analysis of gear losses, andreports that the power losses in derailleurpulleys is generally considerably less thanone percent of the power put into the ped-

als. (He states also that the efficiency ofchain transmission is normally over 99%, ahigher figure than I have seen quoted. I havewritten to ask if he would contribute some-

thing on the subject to Human Power).

Rear-Derailleur DevelopmentSince D-Dayby Frank Berto

Frank Berto is the foremost expert on

derailleur gears, having produced manylucid accounts and tests of different modelsand systems for Bicycling, Bike Tech andother journals. This account of develop-ments in the last half-century or so is full ofinsight and useful comments.

Were There Bicyclesin Milan in 1811?by Les Bowerman

Three years ago my wife bought me ahandsome little book entitled Bicycles, trans-lated from Italian, full of beautiful illustra-tions and a fair amount of nonsense aboutthe supposed history of bicycles. But one ofthe lovely illustrations was of an ordinancethat banned the use of "so-called velocipedes(bicycles) in the streets of downtown

Milan." There were, we all thought, nobicycles anywhere until Von Drais' runningmachines of 1817. Yet the illustration

appeared to be genuine. I wrote to theauthors and publishers and sent copies tovarious museums and friends in Italy tofind, without success, whether or not it wasgenuine, and then sent it to Derek Robertsin Britain. He and his brother founded the

(Southern) Veteran-Cycle Club many yearsago, and he is generally recognized to be theleading cycling historian in the world. LesBowerman gives us a progress report, whichis essentially that the ordinance could wellbe genuine, but, if so, it probably refers tovehicles other than bicycles.

Other PapersThese (above) are the papers principally

concerned with cycling technology. Thereare also several papers on bicycle racing, onColonel Albert Pope and the developmentof mass production, on early bicycle acces-sories, including the trumpet and bugle, andan extensive history by Ross Petty of womenand cycling. The whole volume gives greatpleasure to the human-power enthusiast. Ifthere is space in future issues of HumanPower I may review the earlier volumes.

-Dave Wilson

LETTERSACKERMAN, GORMANAND THREE-WHEELED HPVS

I have just read the article on Ackermansteering for three-wheeled HPVs withinterest. The paper is well written andorganized, but I do feel that somecomments are in order. Mr. Gorman uses a

steering configuration that includes two tierods and a rack and pinion to connect thetrailing arms. I have never seen this systemused on tricycles although it is common inautomobiles. A much simpler and lightersystem uses a single tie rod with a secondsmall tie rod connecting the handle-bartube to one of the trailing arms. The use ofa single tie rod also simplifies the equationsused to compute the trailing-arm angle.

I have written a computer program tomake the calculations and plot the error inwheel turning angle for various turningradii. My results correspond to those of Mr.Gorman's when the value T in his equationsis made zero. It is interesting to note thatthe difference in wheel angles, inside-out-

Volume 13 number 1, fall 1997 17Human Power

side, is correct only at zero turning angleand at the angle at which the trailing armangle is calculated. Maximum error at otherturning angles normally will be in the orderof .03 degrees, but can be as much as 0.1degrees. A scrubbing angle of 0.1 degreesseems to me to be negligible.

If anyone is interested, I will be happy toe-mail the program to him.Lowell W. Zabel Ret (many years ago) Prof Chem Eng UME

As an aside, there is a simple way tocheck wheel scrubbing on an existingvehicle. Place a piece of paper under theoutside wheel while the wheels are turned.Roll the bike forward a few feet. If thepaper rotates, the difference between theinside wheel angle and the outside wheelangle is not correct.(Lowell Zabel and his wife continue to tricyclein their eighties -ed)

ANOTHER BIZARRE IDEAThis last Saturday I had the task of tak-

ing my son to a "fun park" after deliveringmy daughter to a party. My ten-year-old sonand I spent five hours at the fun park.

The major fun was in the go-karts. Thesewere (it appeared) 3 to 5-hp go-karts withfull 360-degree bumpers and a small trackwith bumpers as well. You wore a four-pointharness and the carts were limited to somespeed under 10 mph. Environmental note:they were using the new Honda four-cycleOHV engines, maybe in anticipation ofsmall-engine smog rules about to hit inCalifornia.

Other than getting a sunburn and somewicked bruises from the about-one-g turns(I found out that if you took the turns justright, you could do the whole course fullthrottle) I had a weird idea.

What if you set up a HPV trike race inthe same sort of track? Even at 10 mph, thetrack had so many sharp turns, and theeffect of 10 cars trying to pass on lanes thatwere basically 2.9 cars wide is quite thrilling.The course had five turns, one 180-degreesthat was basically two lanes wide, someother tight corners, and a "sweeper", alsosmall hills and dips.

There's a lot of strategy and the sensationof speed is amazing. The neat thing is thatthe entire race is viewable. And since drivingskill plays a huge role in the outcome itwould be an interesting event. I also thinkthat HPVs would be even more fun than

the gas carts-faster than these 10-mph-speed-limited ones-at least.

Is this a good idea? Maybe there's a trackin [Las] Vegas?William Volk

THE TOUR REVIEWDave Wilson wrote:

"The data are very interesting andimportant. They show pretty convincinglythat "normal" unfaired LWBs with ridershave higher air drag that do the same riderson road bikes".

On this point I disagree. There was noroad bike tested (the MTB in the test wasdefinitely no normal road bike but a racingbike with wider tires!). There was no appro-priate comparison in the test!

The rider on the racing machine couldn'tstand the position for more than one km, ifI remember the value correctly. There arevery few riders who can stand this extremeseating position in the test for a longer time.Therefore they lumped together totally dif-ferent machines!

In addition, the testers noted that thefront fairing of the Peer Gynt could increasethe aerodynamic drag when it was not prop-erly fastened. (They didn't need an expen-sive wind-tunnel test to tell them that!)

Also the rear fairing of the low-racer wasnot well shaped. The photos published inTour showed that the front edge of the rearfairing protrudes away from the body intothe airstream, very poor for aerodynamicdrag. The low-racer should have given betterresults in the test.

If someone wants to write a comment ofa test, or to set up a new test series, ensurethat like machines are compared, includingsimilar fenders, lighting equipment, luggageand so forth. Measuring aerodynamic dragis hard enough: we should get everythingright.Joachim [email protected]. defitp://www-ifia.fzk. de/personal/fuchs

CONGRATULATIONS!(Normally I don'tpublish complimentary letters.We do receive afew. However, PaulMacCreadys letter was so goodfor the morale ofthe many people involved in putting outHuman Power that I could not bring myself toexclude it. Paul MacCready is the chairman ofthe board ofAero Vironment and the IHPVA

internationalpresident. -Dave Wilson)I just received the spring 1997 Human

Power. It is so good I wanted to write tocongratulate you and everyone else involved.Especially delightful was the set of substan-tive summaries of the articles in the table ofcontents. If the momentum can be contin-ued, this will become a very significantjournal.Paul B. MacCready222 East Huntington DriveMonrovia, CA 91016

SLOW ON HILLS?Here is a theory regarding your

comments in Human Power about someTour de France riders being slow on hills:The best hill climbers tend to be small wiryguys because they have the best power-to-weight ratio. But the bigger guys have moretotal power, so they do better in the flats.Their greater weight is not a disadvantagein the flats, and the little guys are not littleenough to get a wind-resistance advantageover them.

I am afraid I can't shed any light onrecumbent hill-climbing issues. Some ofthe physiology studies you have publishedsuggest maybe the recumbent position isn'tthe best for power generation. HasEdmund Burke ever weighed in on this? Invarious places he has published studies thatget right down to the activity of variousmuscle groups, but I haven't seen anywherehe does this with recumbents. The peoplewho make and sell various recumbentexercise bikes make some claims in ads

sometimes, but I have never seen theirresearch published either.

I recently re-read the section in JohnForester's Effective Cycling about recum-bents. He uses lame analysis. Among otherthings, he completely dismisses the comfortquestion by saying that sling seats are avail-able for conventional bikes. In the first placeI know of only one; in the second place it,or any sling seat, can't work very wellbecause of the need for your legs to extenddownward. I am sorry to see that section inwhat is apparently a recent edition of "EC".John Riley

A MINI-HISTORY OF HPVSArnfried Schmitz

It was Laurent Chapuis (some HPV peo-ple will know him!) who asked me: "Whatwas the reason for all [the excitement about

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18 Volume 13 number 1, fall 1997 Human Power

HPVs]? Give as short an answer as possi-ble!" That is difficult, because some reasonscome from a long while ago.

1910: The Prussian government forbidsmotor-paced bicycle races. Speeds ofaround 100 kmph generate some terrifyingaccidents. The race organizers slow downthe bicycles by separating them somewhatfrom the drag shields. There are lots ofrules and definitions. So pure speedbecomes second to show.

1913: There is much laughter about the"Torpedo Bike". How can an added aerody-namic fairing around a bike, adding alsoconsiderable weight, raise the speed? But itdoes! Others try emulating the experiment,but the UCI race organizers stop this forregular racing. World War I does also.

1934: A so-called horizontal bike, legal,but much faster than a classic machinethrough its low and ergonomic construc-tion, is banned from regular racing andfrom qualifying for world records. One ofthe reasons: "Technical bases should beequal for every sportsman", which means"technical progress is dubious in sportcycling". The inventor and constructorC. Mochet dies. He should have taken thepower abuse to court ...

1984: The champion E Moser achieves aworld record, but on an illegal bike.Afterwards the regulations are adapted toallow it. This means "Don't touch an estab-lished hierarchy!"

In the period between these last twoevents of note, 1974, the CaliforniansLambie and Kyle founded the IHPVA, free-ing bicycle development by open racing.The speed increase is fantastic, but the pub-licity impact is small. Today the associationhas clubs in most industrialized countries,but is growing slowly. A young generation iscoming. May everyone remember PeterErnst's words: "Ask not what the club can

do for me, but what I can do for the club?"The UCI, the world's racing body for

traditional bicycles, does have a free catego-ry, at present totally unoccupied. Will youencourage this to be taken over one day?Arnfried SchmitzLioux Gordes, Quartier Gallas, F-84220France.

(We were allowed to publish Arnfied Schmitzsfascinating and valuable article "Why yourbicycle hasn't changedfor 106years" in ourissue vol. 11 no. 3. -ed.)

NOTESSUSTAINABLE-TRANSPORTATIONCONFERENCEby David R. Conn

In mid-1995, a document was posted onthe Internet to the HPV discussion group. Itwas an announcement of an internationaltransportation conference to be held inVancouver, Canada in March 1996. Theconference was to be presented by theOrganization for Economic Cooperationand Development, and hosted by theCanadian and British Columbia govern-ments. I live in Vancouver, and decided toattend the conference to promote human-powered vehicles.

I wrote to the conference organizers inOttawa and offered to organize a displayand make a presentation on behalf of theIHPVA. They replied that they wouldn'thave displays, and it was too late to schedulea presentation, but invited me to attend andto submit a paper for possible publication inconference procedings. I didn't submit as Icouldn't make the deadline given.

The OECD is an independent body rep-resenting 25 industrial countries. The con-ference was called "Towards SustainableTransportation". The preamble in the con-

ference program questioned whether trans-portation could be sustainable, pointingout, "Improvements in fuel efficiency andpollution control during the past twodecades have been more than offset byincreases in the ownership, use and power ofmotor vehicles of various kinds." It addedthat there are 600 million motor vehicles in

the world, and their use is growing wellbeyond the rate of population growth.

There were presentations scheduled overthree days, most of them dealing with landvehicles. 78 papers were summarized in theconference program, to be published later.The best known speaker was AmoryLovins, the author and consultant. On thelast day, all participants convened to discussand adopt a statement of sustainabletransportation principles which beganbluntly, "Our current transportation systemis not on a sustainable path." It placedmost of the blame on our use of the privateautomobile. Bicycles and the use of humanpower seemed to be a very small part of abig picture: how to move huge numbers ofpeople and vast amounts of freight aboutthe globe without continuing to damageour ecosystem.

There was a paper by Vancouver's newnonprofit Alternative Transportation Center.The Center aims to decrease automotive

dependence, with an emphasis on cycling.There was a paper by the activist group V6loQuebec, about efforts to integrate the bicy-cle into the transportation mix in theMontreal area. There was a paper by HughMcClintock, a lecturer at NottinghamUniversity, about planning for urban cyclistsin Britain and continental Europe. Out of78 papers accepted, only those three dealtprimarily with the bicycle.

I expected to see professors and govern-ment policy-makers as presenters and audi-ence members, but was pleased to also seeengineers, executives, activists and planningstudents. Bicycle activists made the point inopen discussion that bicycles are vehiclestoo, and could have a substantial part toplay in transportation becoming sustainable.Because of their remarks, changes weremade in the final conference statement ofsustainable transportation principles.

I certainly learned something fromattending the conference. A few thoughtsthat stay with me are as follows.

Total mobility can't be our ultimate goal.It is possible to have too much mobility, and

that destroys communities. The layout ofour cities and towns is a major part of theproblem; it makes car ownership almostessential (for those who can afford them).

A lot of fine minds among the presentersare working to save our ecosystem from theautomobile, but they aren't consideringmuscle-powered vehicles seriously.

My own influence was limited to leaflet-ing for the IHPVA and promoting human-powered vehicles to other delegates at lunch.Had I known the hotel floor plan, I couldhave parked my Tour Easy recumbent inview of the delegates to create a subversivedisplay. I hope that other IHPVA memberswill attend transportation conferences tohelp get our point of view across to govern-ment and industry decision-makers. Manyof them have never heard of human-pow-ered vehicles, and have no idea of their capa-bilities or potential. If members would liketo order conference procedings, contact:Julie CharbonneauTowards Sustainable DevelopmentCanadian National Organizing CommitteePlace Vincent Massey351 St-Joseph Blvd., 13th fl.Hull, PQ, Canada KIA OH3

Human Power Volume 13 number 1, fall 1997 19~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~Volume 13 number 1, fall 1997 19Human Power

TECHNICAL NOTEHow thin may thebraking rim of my wheel get?by Chris Juden

Dick King asks how thin a rim maywear (due to braking) before failing andJim Papadopoulos asks if such failures aredisastrous.

I wrote an article entitled "ExplodingRims", for the February 1993 issue of ourCTC magazine (Cycletouring &eCampaigning), in which I fully describedthis problem. Leading up to that article Ihad been receiving an increasing number ofreports of blown-out rim flanges, someaccompanied with sections of rim, and havesince received many more.

The design of cycle rims changedsignificantly in the 1980s. Steel rims andstraight-sided alloy went out, hook-edgedrims became ubiquitous. By the early '90s alot of these rims had become worn enoughto be blown away by tyre pressure, buttheir users were not aware of that (evenwhen changing a tyre) because the thick-ened edge conceals the state of wear of thethinner section of rim wall immediatelybelow it. And while a few rims failed soft,gradually bending outwards and warning ofimpending failure by causing brake snatch,others went with a bang.

When this happens a length of the rimedge peels off, usually but not always fromthe joint (welded rims also fail), and theinner tube pops through the resulting gap.Although a lot of failures occur while inflat-ing the tyre, some quite serious road acci-dents have also resulted. Some riders havecrashed due to loss of control upon suddendeflation of the tyre and one was alsostabbed in the back of the leg by the flailingstrip of rim edge!

I cannot single out any particular makes:most of those commonly used by our mem-bers are represented in my collection of bitsof exploded rim. All have hooked edges(road and off-road types are now similar inthis respect). It seems that in the past alloyrims just got thinner and thinner until theywore through into the pinning hollow, orthe edges progressively bent over andbecame sharp, or they simply lacked thestrength to stay true. But I am aware of onemanufacturer (Alesa) who has recognisedthe danger of such failures and produces arim (with the Alesa Safety Line feature)which is designed to wear through into the

pinning hollow before the flange becomesthin enough to fail.

The thickness of rim wall at explosivefailure obviously varies with materialstrength and inflation pressure. The thickestI've seen is about 0.7 mm, the thinnest 0.5mm. But this measurement isn't easy tomake prior to failure, due to the hookededge, and one cannot expect average ridersto check their rims in this way.

So long as you know how wide and thickthe rim was to start with you could checkoverall width; and to give a margin of safetyI recommend discarding a rim after 1 mmof total wear. But even this is perhaps a littletechnical for the average bicyclist.

I suggest a simple proof test every fewhundred km after 3000 km (the shortestdistance I've known any road rider wear arim out-off-road use can be much moreabrasive). Inflate the tyre to a pressure onebar (15 psi) or so higher than you'll ever rideat, wait for a minute, during which intervalyou may usefully spin the wheel and inspectthe tyre for distortion or other signs ofweakness, then let it down again to normalpressure. I shouldn't need to explain to thisreadership that proof testing is a respectableengineering procedure. If nothing wentbang or looked out of shape, then the wheelshould be as safe to ride as it was before-hand. But it's advisable to wear overalls,gloves and goggles when testing-whichshould be scheduled for when your favouritebuilder has the right kind of replacementrims in stock and not the day before a tour!Chris Juden, CTC Technical OfficerCyclists' Touring Club UKTel: +44 (0) 1483 417217Fax: +44 (0) 1483 426994e-mail: cycling@ctc. org. ukhttp://www. ctc. org. uk(Chris Juden and Mark Marsh were kindenough to allow me to use their contribu-tions in the "HBS: hardcore bicycling sci-ence" mail list, organised and moderated byJim Papadopoulos. -ed.)

Another comment on how thinmay the braking rim get?by Mark Marsh

Jim Papadopoulos wrote "Has anyoneout there actually experienced the failure -is it disastrous (sidewall blows off, wheeljams) or benign (sidewall spreads a little,grazes the brake pad)?

Both failure modes you suggest can

happen: the rims often go when beingpumped up. However, both my experienceshave been of the catastrophic type. The firstwasn't so bad: the rear rim blew a sectionout while descending off road and as aconsequence the rear tyre blew out. It mayhave locked the rear wheel but since I wasbraking quite heavily at the time I didn'tnotice. The most dangerous part of it wasthe 400-mm length of sharp rim wall thatwas flapping around my legs until itfatigued off (the rim not my leg!).

The second occasion was much worse:the front rim blew out whilst descending a30-degree dirt track at about 7 m/s (15mph). It locked the front wheel instantlyand I was thrown straight over the handle-bars. I managed to tuck and roll, but it wasquite a hard landing nonetheless.

I now run ceramic rims on the mountainbike. The ceramic coating makes the wheellast a lot longer: it is just starting to wearthrough after two summers and winters ofriding (most Sundays) in quite poor condi-tions. As a rough guide we (both my usualriding companions use ceramics) think theytriple the wear life of the rim. Since theycost roughly three times the price of anuncoated rim this saves the cost of a coupleof rebuilds (and the inconvenience).Currently they have done twice the mileageI would expect from an uncoated rim andthey still have 85% coated surface and the'normal' rim to wear through before theywill need replacement.

If you tend to wear out a rim beforebreaking it then I would recommend theceramic coatings; obviously if you tend towreck rims through impact they offer littleadvantage. We seem to get about 3000 km(1800 miles) in dry conditions, and 2000km (1200 miles) in wet.

Interestingly I am still using the originalXT brake pads fitted when I put the rimson: they are now nearly worn out. NormallyI would expect to get through a set of LXpads every 6-8 weeks in the winter. I amtold that this is probably a function of thechange from LX to XT pads rather than thechange to ceramic rims but I believe that theceramic coating also extends the life of thepads due to the lack of the grey abrasivesludge that the rim wall normally turns into.Mark Marsh < marshm @vicorp. co. uk>

20 Volume 13 number 1, fall •1997 Human Power20 Volume 13 number , fall 997 Human Power

ZACH KAPLAN ON FAIRINGSThis was written by Zach Kaplan in thehpv@ihpva. org list, and is reprinted with hispermission - Ed.

Unlike many of the fully faired two-wheeler riders, most of my riding experiencewith them has been on public roads, notclosed track. In fact I have been on closedtracks with them only a total of a few hoursat HPV events.

In general I really like riding fully fairedtwo-wheelers on the road. I find the fairingmakes me much more visible and I get a lotmore respect and courtesy from motoristswith a fully faired recumbent than on anunfaired recumbent-which in turn getsmore respect than a conventional uprightbike. Not only does the fairing greatlyincrease my visibility but it also makes theHPV look like a heavier vehicle than it real-ly is. Motorists often ask me if it is electricor what type of motor it has. Most find ithard to believe it is just a pedal bike. This isa good image to put forth: if they think it isa heavy motorized vehicle they are going tobe less likely to hit it for fear of doing majordamage to their car.

The increased aerodynamic efficiency ofthe full fairing allows me to keep up withthe speed of traffic on 40-50 km/h roads.This allows me to take a full lane which issafer than being off to the side going slowerthan the traffic flow. The effect of passingcars also gives me more of a draft with thefull fairing than on an unfaired recumbent.A minivan two car lengths up ahead willeasily allow me to bring my cruising speedup to 55 km/h if it accelerates graduallyenough. I often get these semi-free rides forconsiderable distances while still being ableto keep a safe following distance. I love get-ting passed by huge trucks. I watch as myspeedometer goes up several km/h after thetruck passes. Surprisingly the big trucksrarely create handling problems. They tendto push me away slightly as they approachbut never by much. Oncoming big trucks athigh speed on a two-lane road are more of acause for concern. The shock wave fromthem hits like an explosion. The bike moveslaterally a bit for a second or so but onceyou get used to that it is no big deal. If I amgoing extremely fast I will slow down if I seean oncoming truck on a two-lane road.Once in a time trial I didn't bother slowingdown and it was no big deal: the oncomingair from the truck felt as if it were hard

braking, but after a second or two every-thing was back to normal.

Here in the San Francisco Bay Area it isoften windy but not usually extremelywindy. I have to remove the fabric mid-fairing only a few times per year aroundhere. However there are some gustydownhills such as the one going down intoSausalito from the Golden Gate bridge. Ona calm day or at night I let it fly at close to80 km/h on this hill. On a windy day I just"burn out" the brakes and hold it down to30 km/h or so. This isn't a very long hill.

For dealing with very gusty conditionsin high-traffic areas I have developed atechnique I call "going with the flow." I dothis when there is a lot of traffic on theroad and I don't want them to pass meclosely in case I need that section of theroad due to a gust. I simply keep a loosegrip on the handlebars and let the wind dowhat it wants to with the HPV. I'll let itmove laterally about 1 metre in eitherdirection if it's really gusty. I am incomplete control while this is going on andcan always use the brakes or lean into thegust if I want to hold a straighter line. Itreally freaks out the motorists behind methough. They get 'way behind me which iswhere I want them, and don't attempt topass unsafely.

I have never heard of faired bikes beingoutlawed in certain areas. Can you cite anyexamples? I can tell you that if every cyclistriding today were riding a fully faired bikeusing today's technology they mostcertainly would be banned in short order.Right now the faired bikes are fairly easy toride in no-wind conditions but take a lot of

skill to ride in windy conditions,particularly at higher speeds. I think I oncetold an upright rider that he was usingmore muscle power but I was using morebrain power to ride. I of course don't wantthings to stay this way. I don't want fairedHPVs to remain something elitist,requiring special skills. I would like to seemany more faired HPVs out there on theroad. But we are going to need to designmore easily controllable vehicles before thiscan happen. This is where my thoughtsturn to three-wheelers, semi-automaticcontrol-surface-compensation systems, andlower riding positions. Keep in mind I amno expert on what will or won't work. Ihave never had the pleasure of riding a fullyfaired three-wheeler or ultra-low faired two-

wheeler on a windy day. Those designsmight not be enough of an improvementor they might be. I don't know yet. Anyonewant to loan me one so I can tell you?

Hugh Murphy, the organizer of theDeath Valley double century, phoned meup when he received my registration andtold me I wouldn't be allowed to ride withthe full fairing. I ended up telling him abunch of technical terms and telling himhow the HPV I was using was suitable forthese conditions and how I would be verycareful. He ended up giving me specialpermission to ride fully faired so long as Iabsolutely would not ride beside any othercyclists except when passing and give themas much space as possible while passing. Iended up doing the ride with the fullfairing and it did turn out to be quitewindy. About two thirds of the way intothe ride I determined conditions where toounsafe to keep the fabric on so I took it offand folded it up completing the rest of theride with just the nose and tail installed.Even then it was hard to keep anythingclose to a straight line. Everyone wasgetting blown around on that ride. I heardthat a tandem got blown off the road.Zach Kaplan CyclesMuir Beach, California, USAPhone: 415-381-5723

CALL FOR PAPERS FOR DENMARK1998 EUROPEAN CHAMPIONSHIPS

A human-powered vehicles symposiumwill be held in conjunction with the HPVEuropean championships in Roskilde,Denmark, 5-9 August 1998. The sympo-sium, organized by Carl Georg Rasmussen,will take place at the Roskilde TekniskeSkole on Wednesday, 5 August 1998.

Contacts: Dr. Andreas Fuchs, Ingenieur-schule Bern HTL, Morgartenstrasse 2c,CH-3014 Bern, Switzerland. Phone:+41-31-333 0625; .Dr. Joachim Fuchs, Morgenstrasse 45, D-76137 Karlsruhe, Germany. Phone: +49-721-826539; ; homepage: http://www-ifia.fzk.de/personal/fuchsOther links: http://www.ihpva.org/;Dansk Cyklist Forbund:http://webhotel.uni-c.dk/dcf/

Deadlines: for abstracts, 1 March 1998;for camera-ready papers, 1 June 1998.

Volume 13 number 1, fall 1997 21Human Power

BICYCLES AND THE TAX-MANby Richard Veffer

In a press release dated August 18 1995,Secretary of State Vermeend, of Finance,[NL] announced that commuting by bicyclewill finally become attractive in terms of tax-ation. As per the first of September 1995, anumber of measures are in force in connec-tion with this announcement.The following measures have been taken:1. The Secretary of State wants to encourage

employers to give a bicycle to theiremployees for commuting. If the value ofthe bicycle (as determined by the recom-mended retail price of the bicycle) isbelow Dfl 1500 (including tax), incometax will only be levied once for theamount of Dfl 150. It is allowed to giveone bicycle per three years only.

2. If the bicycle is used for commuting only,and as such remains property of theemployer, no income tax is levied. Again,the ruling that the recommended retailprice of the bicycle has to be Dfl 1500 orless (including tax) applies.

3. Probably with the mostly unfairedupright bicycles in mind, on which therider is exposed to the elements, theSecretary of State has decided to allow theemployer to pay for the cost of publictransport through a railway 5-return tick-et or universal ticket, without beingtaxed. However this decision is only validfor the bicycle made available by theemployer, not for the employees whohave been given a bicycle. Take note, ifyour employer gives you money so youcan buy your own tickets this rule isunlikely to apply.

4. Furthermore, items directly related to thebicycle, such as foul weather clothing,locks, maintenance, etc., can be reim-bursed by the employer up to an agreedlimit, after consultation with the taxoffice.

5. If you are not given a bicycle by youremployer, or have one made available toyou, and you use your own for businesstrips, your employer is allowed to pay youup to 12 cents per kilometer untaxed. Ifyour employer does not give you thisallowance, you are allowed to deduct 12cents per kilometer from the taxed costs(however this only applies if the employeepays for both bicycle and bicycle relatedcosts).Finally, there are two more rulings

which should make it attractive for theemployer to give bicycles away or makethem available:* The full cost of bicycles with a cost priceof Dfl 1000 or less can be deducted fromcompany profits in one go, and so they donot have to be depreciated during the eco-nomic life cycle* Bicycles with a cost price of more thanDfl 1000 can be depreciated in three years,even if the economic lifespan is longer.

At the tax office a central informationsource will be set up: the Bicycle-informa-tion point. Here, both employers andemployees can get all the answers to ques-tions related to the taxation of bicycles.

With this arrangement Vermeend showsthat is he is not deaf to the cries from the(organised) bicycle industry. For the recum-bent cyclist, the rulings are not applicable intheir standard form. The recommendedretail price of recumbents is well above theDfl 1500 mentioned before.

This complication has two possible solu-tions: on the one hand, the employee who isgiven a bicycle worth (say) Dfl 3250, coulddecide to pay Dfl 1750 himself. In this case,he is only given Dfl 1500 worth of (part ofa) bicycle. In this situation it is to be expect-ed that the rulings described above areapplicable.

Another solution could be reached if theemployee gets in touch with her or his owntax inspector (note: only the employees taxinspector is duly authorised to make anyagreements, not the [income] tax inspectorof the employer!). He or she can present thesituation to the tax inspector and makeagreements as to what amount should beearmarked as income. In 1994, before thisarrangement existed, I myself was able toreach an agreement with the tax inspector,that said that for a recumbent worthDfl 2350, Dfl 150 one-offwould be regard-ed as taxable income.

According to the newly created rulingthis amount will possibly be slightly higherin the future, but a similar tax agreementwill still be cheaper for the employee thansharing the costs of the bicycle with theemployer.

Should you have questions or commentsabout these rulings, you can reach me viathe editors of HPVNieuws.Translated by Wouter Suverkropp(1 US dollar was about 1.68 Dfl [when thiswas translated], wbs)

EDITORIALSThe outing of impotence

Bicycling displayed two acts of couragein 1997. One was an article in the Julyissue generally favorable to recumbents.The second was a follow-up in the Augustissue in which a senior editor confessed notonly that he had been rendered impotentby riding on hard bicycle saddles (there wasan accompanying article about the topic)but had switched to a recumbent bike, atype for which he normally had somedisdain, and after only six weeks hadconsiderably recovered. To most of us inthe HPV community the pain and nervedamage in the neck, wrists and crotch thatcome from long-duration riding in thetraditional bicycling position are wellknown (incidentally the medical emphasisin the Bicycling interview was on blood-vessel damage), but it was still remarkablethat the principal main-line bicyclemagazine would be so broad-minded andhonest. It was obvious that this was anexplosive issue that tabloid journalists,maybe others too, in all media would wantto exploit. On September 18, 1997 theABC program 20-20 interviewed LisaGosselin, Bicycling's editor, who hadobviously been subjected by the bicyclemanufacturers that advertise so widely inher magazine to the kind of pressure thatthe tobacco companies used to put oneditors who dared to publish an article thatsuggested that smoking was anything butgloriously healthful. She chose her wordsvery carefully. "Yes, he is still bicycling,"she said in response to a question from Dr.Timothy Johnson, ABC's in-house medicalspecialist. "He adjusted his riding style."(That at least is a tacit acknowledgmentthat recumbents are now main-line

bicycles).The tiny recumbent-bicycle industry has

been helped generally by these events. Wehope that the manufacturers of traditionalbicycles and components will react in amanner as different from that of thetobacco companies as possible. For yearsthere have been saddles available that havepromised to avoid putting pressure ondelicate areas for males and females. Therehave been handlebars that allow frequentchanging of the wrist position and thatreduce pressure on the ulnar nerve. Theavoidance of damage to the neck seems tome the most intractable. At the end of the

22 Volume 13 number 1, fall 11997 Human Power

22 Volume 13 number , fall 1997 Human Power

first twenty-four hours in a typical RaceAcross America, over half the lean, superblyfit athletes who start have quit, most, Ibelieve, because of neck pain. Even in whatseemed like a comfortably uprightmountain-bike position on wide saddlesmy wife and I, in a recent low-pressure1200-km tour of New Zealand's SouthernAlps, had severe pain in all three areas ofconcern, but the neck pain lasted longestafter the trip was over. Some people havemade periscopes so that they can ride withtheir heads comfortably down. That seemsan extreme response. HPV enthusiasts wantto co-exist with a healthy and healthfultraditional-bicycle industry, and we wish ita speedy and effective response.

-Dave Wilson

GUEST EDITORIALRecord rules and altitudePaul Buttemer

The recent debate about IHPVA recordrules in general, is one that we have muchto gain from resolving. I believe that thecontext of the debate should be expanded,and that there is far more at stake thansimply "who's best".

Firstly I'd like identify myself, so thatreaders will have an idea of my perspective.My involvement with the IHPVA has beenmostly as a participant in IHPVAsanctioned events. I have been veryfortunate to be able to ride, since 1990, inthe Varna vehicles built by GeorgeGeorgiev. I have competed in the annualIHPVA Championships in 1990(Portland), 1991 (Milwaukee), 1992(Yreka), 1994 (Eureka), and 1996 (LasVegas), and in the 1993 Colorado SpeedChallenge. George and I hold one record,namely the one-mile flying-start TT.George's vehicles have, along with goodresults in other events, placed first andsecond in the 200-m sprints at the 1994and 1996 Championships. My personalinterest, though, goes deeper than that ofan "engine", as I am fascinated with thevery young science, and the art, ofaerodynamics.

There is no question that altitude affectsperformance, and at this time we can'taccurately quantify how much it does, asthere are too many variables to consider.So, it is quite reasonable that onecompetitor, who doesn't have access tohigh-altitude venues, should want to

qualify the performance of anothercompetitor, who does have this access. Thesimple solution, one which we are currentlypursuing, is to make one or more categoriesbased on altitude.

Furthermore, many factors, altitudebeing only one, affect performance on agiven course. Let me cite an example: at the1994 Championships, the sprint course wasright at sea level. In the cold, humid, butstill, early morning air, my top speed wasabout 77 kmph. Later in the warmer, lesshumid air, I was able to attain about 85kmph in a gusty cross wind. At this venue,the environmental change resulted in a sub-stantial difference in performance. Backhome, there is a stretch of road, also at sealevel, that we (Team Varna), occasionallypractice sprints on. The pavement is verygood, but the slope is such that one point inthe course pokes up just barely above the2/3 percent line, making it illegal for anyrecord activity. It is necessary to use thisroad very early in the morning to avoid traf-fic, so generally we're out on it at 5:00 A.M.or so. I can attain speeds of about 100 kphon this course in still wind conditions. So,when we compare this course with the onein Eureka, which is at the same altitude, wesee a dramatic difference of almost 25kmph! My point is, that the situation weface in qualifying performances is far morecomplicated than just resolving the altitudequestion.

We could go ahead and impose altituderules, but this is not going to prevent onecompetitor from having a large advantageof another, by virtue of other factors to dowith the air and with the course surface.

When we are dealing with streamlinedvehicles (as opposed to a normal unfairedbicycle), factors other than altitude becomemore significant. We simply cannot, at thispoint in time, compare performances ontwo different courses, even if they are atexactly the same altitude. If we really wantto "make things fair", we need to impose amyriad of rules and restrictions, some ofwhich haven't even been considered yet.This will take much time, will probablygive rise to some ill feelings, will makefewer venues available, and will cause fewerand fewer competitions to take place. Weneed more competitions, not fewer, to takeplace under any reasonable conditions. Theonly way to find out "who's best" (if this iswhat you are interested in), is to have

competitors go head to head on a numberof varied courses. Beyond this, ourcompetitions are the proving grounds forour theories on aerodynamics, powertransmission efficiency, and the dynamicsof the human engine. They can be thesource of immensely valuable scientificdata, if we choose to record these data. Theaccumulation of these data will eventuallyallow us to determine accurately how suchthings as altitude, barometric pressure,temperature, humidity, slope and thecourse surface affect performance. I haveseen (notably in Human Power) all kinds oftheories about the effects of these factors,so it is obvious that they are of generalinterest. What better place is there to apply,and possibly verify, these theories than dataaccumulated, without bias, in real-worldcircumstances?

At the recent championships in LasVegas the course for the 200 m sprints washeld on an airport runway, with a gradientsomewhere between one and two percent(exact figure unknown at the time). Mysubjective estimate is that this gradientadded about 20-22 kmph over what ourspeeds would be if the course was level. (Idid this by travelling down and up thecourse at various levels of effort, and foundthat the difference in speed, between downand up, was always 40-44 kph at the sameeffort level. This was a very crudeexperiment, at best, but it was interestingfor me to know about how much the slopewas adding to our speeds.) The speeds wereunrealistically fast, but, I suspect that everycompetitor thoroughly enjoyed the thrill ofbeing on this course. It would be a shameto reduce the possibility of using such acourse, which seemed to be at the outerlimit of armchair reason.

In conclusion, I would like to proposethat we move our focus away from tryingto determine fair rules for world records. It

cannot be done. Instead we should put ourefforts into having more competitions, andto the creation of a database that willcontain results of every performance anddetails of the factors surrounding eachperformance. We could still at any time, ifwe want, design an arbitrary set of criteriaas a filter for the database and pull out an"official" world record.

Paul Buttemer 905 Sandpines DriveComox, BC, Canada V9M3V3

Human Power Volume 13 number 1, fall 1997 23~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~23Human Power Volume 13 number 1, fall 997

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