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Chuck Webb
August 26th 03, 12:40 AM
Another great write-up, and still an amazing ride both for distance and
average speed on a 24"...

> Even allowing for the back problem, the ratio alone does not make the
> uni the same as a Coker for speed.


And yes, you can do all the math you want about crank ratio and foot
speed but...

on a direct drive vehicle, the only way to really gear it up is a bigger
wheel...more distance travelled per rev. (Blue Shift excepted, that is,
of course)!

Chuck


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Klaas Bil
August 26th 03, 09:56 AM
Chuck Webb wrote:
> *you can do all the math you want about crank ratio and foot speed
> but...
>
> on a direct drive vehicle, the only way to really gear it up is a
> bigger wheel...more distance travelled per rev. (Blue Shift excepted,
> that is, of course)!*

Hmm. I'm not sure that that is technically correct: does a bigger wheel
gear up anything? Anyway, if you mean that the famous Constant Foot
Speed Hypothesis is worthless you should try various crank sizes. The
CFSH may have its weak points leading to such correction issues as a
'fear factor' but it surely has a right to live!

Klaas Bil - fan of the numerical approach


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Mikefule
August 26th 03, 03:16 PM
Well, thank you both for your concern (this typed with a pen held in my
teeth as I lie on my bed of pain...)

I went into work today but had to give up and come home. I'm still
walking like Quasimodo.

The Constant Footspeed Hypothesis is, of course, a tongue in cheek
expression.

The idea is that (if you accept the hypothesis) your feet travel at a
given speed, whatever the size of the cranks. Therefore, if the cranks
are twice as long, it takes your feet twice the time to do one complete
revolution - or vice versa.

"Gearing" comes from the ratio between the length of the crank and the
radius of the wheel. This is because the circumference of the circle
your feet make is 2 x PI x R (where R = Radius = the length of the
crank) and the circumference of the wheel is also 2 X Pi x R (Where R =
the radius of the wheel).

So, the theory goes, if you have a 20 inch unicycle with 5 inch cranks,
or a 24 inch unicycle with 6 inch cranks, the ratios are the same. (5 =
half the radius of the 20 inch wheel; 6 = half the radius of the 24 inch
wheel.) For every yard/metre/cubit/pasang that your foot moves, the
wheel will move 2 yards/metres/cubits/pasangs.

(Anyone else sad enough to know about pasangs? :0) )

So applying this hyposthesis to the Coker (36 with 6 inch cranks) and
the 24 with 4 inch cranks, we see that the ratios are identical. Does
this mean that the unicycles have identical speeds? The question is too
simple.

We have to consider:
Maximum speed in a straight line on the flat
Average speed over a long journey on the flat
Average speed on a varied journey with obstacles
Comfortable cruising speed

It would be surprising to find that a 36/6 and a 24/4 would be identical
in all categories.

We can consider the matter easily by reductio ad absurdam (not quite the
normal use of the expression, I admit) and consider a 6 inch diameter
wheel with 1 inch cranks, and a 6 foot diameter wheel with 12 inch
cranks. Would either of these perform the same as the Coker? The
ratios are the same, but we don't need practical experiments to convince
us that given a choice of a 6/1, 36/6 and a 72/12 (all wheel
diameter/crank length in inches) only one would be a sensible coice for
speed or distance.

Similarly, the standard out of the box 20 has 5 inch cranks, the
standard out of the box 24 has 6 inch cranks. Would we expect similar
performance from them? To an extent, yes. But what about a 4 inch
wheel with 1 inch cranks, or a 40 inch wheel with 10 inch cranks?
Clearly not.

The Constant Footspeed Hypothesis is a useful guide when comparing the
perfomance of mid-range wheel sizes and crank sizes. The reason it
isn't completely accurate is that it excludes the most important part of
the unicycle: the rider.

The rider varies with:
Leg length
Ratio of lower leg length to upper leg length
Skill
Experience
Courage

Also, some riders are better able to apply lots of force slowly, whereas
others are better able to supply a small amount of force quickly. You
get sprinters, middle distance runners and Marathon runners. It's the
same with unicycling.

Anyway, by riding a long distance (24 miles) on a 24 with 102s, i have
been able to make a direct comparison with my experiences on a 28 with
110s and a Coker with 150s. According tot he hypothesis, the 28 should
be fastest (it isn't) and the Coker and 24 should be identical (they
aren't).

The answer seems to be, big wheels are generally faster than small
wheels, given broadly similar ratios. The 'gearing' of crank to wheel
is about the same, but the 'gearing' of thigh to wheel is different.


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fall."
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GILD
August 26th 03, 03:40 PM
Mikefule wrote:
> *(Anyone else sad enough to know about pasangs? :0) )
> *


no, but there isn't a form of 'wildlife'
(http://www.hyperdictionary.com/dictionary/pasang) i cant find with my
trusty old google machine

;)


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Mikefule
August 26th 03, 05:46 PM
Not the meaning of 'Pasang' that I had in mind. :0)

Off topic at first:

If memory serves, the Pasang was a unit of measurement in the fictional
world or Gor, the setting for a huge number of blood 'n' guts and sword
'n' sworcery type fantasy books which were popular in the 1970s or
thereabouts. They had titles like, "Outlaws of Gor", "Swords of Gor",
"Dragon Riders of Gor" and so on. These may not be actual titles, but
I'm sure you get the idea. As a spotty teenager, I read many of them,
along with Brak the Barbarian (the poor man's Conan!), and Neq the
Sword, Var the Stck, Sos the Rope, and (most embarassingly) rather too
many of Ann(e) McCaffery's Dragonblurb novels.

The Pasang was a unit of measurement for distances we would measure in
miles or kilometres (as opposed to inches, yards, parsecs, centimetres
etc.)

My original reference to Pasangs was spontaneous. I knew the books were
about Gor. To research this particular post, however, I have checked
Google for 'Gor' and I found that the writer's name was John Norman.
Furthermore, there seem to be several websites devoted to "Gorean
philosophy," and the like, which suggests to me a 'fandom' similar to
that attached to Star Trek, Doctor Who, Blake's 7 and so on.

Back on topic: I believe John Norman has still to write the two future
classics of the genre: Unicyclists of Gor, and Giraffe Riders of Gor.
Any plot suggestions? ;0)

As for the sympathy! If I'd cut my leg and posted a picture... but oh
no, I have to ride 6 miles, crippled with pain and nothing to
photograph. Miserable lot.


--
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"Our greatest glory is not in never falling, but in rising every time we
fall."
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Chuck Webb
August 26th 03, 09:30 PM
> Well, thank you both for your concern (this typed with a pen held in
> my teeth as I lie on my bed of pain...)

Yes, please accept my sincere apologies...i got so caught up in your
beautiful prose, then started thinking about the wheel size/crank length
thing, and forgot all about your pain! :(

So...i offer my belated sympathy, and hope that you recover fully and
quickly so that we can once again read of your journeys! :)

Chuck


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Klaas Bil
August 27th 03, 02:20 AM
Mikefule wrote:
> *Well, thank you both for your concern (this typed with a pen held in
> my teeth as I lie on my bed of pain...)*

Concern? Hm yeah, Mikefule I hope you feel better soon! But I know that
even the worst backpains go away. Been there done that. Pain or no pain,
I have to go through a set of neat exercises every couple of days to
keep it at bay.

Talking about concern, I was concerned though about the "attack" on the
elegant CFSH, launched by yourself maybe a year ago. It didn't come
across at the time as a tongue-in-cheek thing and I still regard it as a
valid first approximation albeit within a limited range. Hell, since the
CFSH was brought into daylight, I have timed myself more than a hundred
times on a variety of wheel and crank sizes out of sheer intriguedness
with the concept. Yes I will report some day.

I didn't know about Pasangs, not even about cubits I must admit. And a
yard? Well I've heard about that but there seems to be no standard yard;
just think of the Scotland yard and the back yard. So I will use the
S.I. system exclusively :-) .

Klaas Bil


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duaner
August 27th 03, 06:21 AM
Klaas Bil wrote:
> *
> ... And a yard? Well I've heard about that but there seems to be no
> standard yard; ...*


In the USA, a yard is defined as three feet -- exactly 0.9144 meters.


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GILD
August 27th 03, 09:12 AM
Mikefule wrote:
> *Not the meaning of 'Pasang' that I had in mind. :0*


u say pasang, i say piesang...
(an attempted take-off of the tomeito/tomahto joke that requires u to
know that 'piesang' is the afrikaans word for banana in order to realise
that it's a) not funny, and
b) thoroughly irrelevant)

:rolleyes:

Mikefule wrote:
> *If memory serves, the Pasang was a unit of measurement in the
> fictional world or Gor, the setting for a huge number of blood 'n'
> guts and sword 'n' sworcery type fantasy books which were popular in
> the 1970s or thereabouts*


i've never heard of any of this but your mention of pasangs lead to a
fascinating afternoon's study of gorean philosophy
this is one of the main reasons i'm truly glad that i picked up
unicycling
i'm rather judgemental by nature despite the howls of disbelief from the
back of the audience
and in a previous (pre-uni) incarnation, would probably have looked at
the followers of gor and muttered something about 'get a life'
finding personal enjoyment atop one wheel seems to have tempered my
mutterings with a realisation that the high ground i'm attempting to
take in my judgement of the free time pursuits of others is rather
skinny

Mikefule wrote:
> *which suggests to me a 'fandom' similar to that attached to Star
> Trek*


now i have to wonder if trekkies look at this group as being 'weird'

Mikefule wrote:
> *Back on topic: I believe John Norman has still to write the two
> future classics of the genre: Unicyclists of Gor, and Giraffe Riders
> of Gor. Any plot suggestions? ;0)*


lots!!
:D :D :D


--
GILD - Waffle-tosser

The second half of a man's life is made up of nothing but the habits he
has
acquired during the first half.
-- Fyodor Dostoevsky


'pleez check this out' (http://www.reuniteluna.com/)

JUST SAY 'KNOW'!

Namaste!
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Phil_Donaldson
August 27th 03, 09:38 AM
Mikefule wrote:
> *My route was from Trent Lock at Sawley up to the canal basin at
> Langley Mill.*

Great write up Mike. Until you wrote this, I would never have thought of
riding up that towpath, probably because I find the landscape aound
LE/Ilkeston so ugly.

Glad yer gorom' OK, yoth.*


Phil

*Local slang meaing "Glad to hear that you made it home alright, old
chap.


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wobbling bear
August 27th 03, 04:33 PM
Mikefule wrote:
> *
> Also, some riders are better able to apply lots of force slowly,
> whereas others are better able to supply a small amount of force
> quickly. You get sprinters, middle distance runners and Marathon
> runners. It's the same with unicycling.
>
> Anyway, by riding a long distance (24 miles) on a 24 with 102s, i have
> been able to make a direct comparison with my experiences on a 28 with
> 110s and a Coker with 150s. According tot he hypothesis, the 28
> should be fastest (it isn't) and the Coker and 24 should be identical
> (they aren't).
>
> The answer seems to be, big wheels are generally faster than small
> wheels, given broadly similar ratios. The 'gearing' of crank to wheel
> is about the same, but the 'gearing' of thigh to wheel is different. *



I have read recently that physiologists that studied cycling came
to the conclusion that , contrary to cyclist's popular belief, the
optimum pace
for pedaling is much slower than previously thought.
A cyclist should try to keep around 70 strokes/minutes
and thus will be able to go with optimum economy.

are we unicyclists burning our heart out?
unless I am mistaken this would approximately mean
6.5 Km/h on a 20" or 12+ km/h on a Coker
(btw I do not even go that fast and am out of breath !)

bear


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Klaas Bil
August 27th 03, 04:42 PM
wobbling bear wrote:
> *A cyclist should try to keep around 70 strokes/minutes
> and thus will be able to go with optimum economy.
> *

This may be true but I'm not sure it contrasts with cyclist's popular
belief. It would be strange if it turned out that all cyclists have done
it 'wrong' until today. Cyclists, especially when they are racing, are
interested more in high speed than in optimum economy. My car is also
more economic at low engine RPMs but then it's not that fast.

Klaas Bil


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wobbling bear
August 27th 03, 05:48 PM
brian.slater wrote:
> *
>
> That's interesting, the last _scientific_ report I read about the
> efficiency in cycling said 60 PPM. Of course their idea of efficiency
> was the maximum co2 production=maximum efficiency. However, that will
> burn you out for DAYS after, as that uses your reserves to create
> maximum -short term*- power. If you want to last longer (more than
> an hour) and therefore go farther (AND be able to do *anything* the
> next day) somewhere around 80-100 is what is what I've heard in
> cycling circles.
>
> It all depends on what you'r trying to achieve, extremly short high
> speeds, or looong trips.
>
> Id be interested in the source you found.
>
>
> Or in long distance when doing the tour thing.
>
> And if you're doing Tour de France, you need high speed and endurance.
>


in fact I've read that in a "pop" review about science I found in my
father's home
I do not remind wether it was "science et vie" or "science et avenir"
(- french reviews- may or june or july 2003 issue)
there was a diagram showing that for long efforts going after 80/100
strokes was a bad idea (though popular)
it was stated that the brain wants higher rates and that's why
generation of cyclists got it wrong!

I'll try later to find similar resources on the net

bear


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Ken Fuchs
August 27th 03, 10:30 PM
wobbling bear > wrote:

>I have read recently that physiologists that studied cycling came
>to the conclusion that , contrary to cyclist's popular belief, the
>optimum pace for pedaling is much slower than previously thought.
>A cyclist should try to keep around 70 strokes/minutes
>and thus will be able to go with optimum economy.

I would presume that the crank length was about 170mm (close to the
average crank length for bicyclists). As crank length is shortened, the
optimal cadence will almost certainly increase, though perhaps not
linearly (would the optimal cadence double when crank length is halved?)

>are we unicyclists burning our heart out?
>unless I am mistaken this would approximately mean
>6.5 Km/h on a 20" or 12+ km/h on a Coker
>(btw I do not even go that fast and am out of breath !)

Yes, unicycists' higher cadence does indeed place greater demands on
their hearts and lungs, but isn't that part of the fun?

Sincerely,

Ken Fuchs >

onewheeldave
August 28th 03, 01:45 AM
Danny Colyer wrote:
>
> 8 years later I still religiously perform a set of back stretching
> exercises every morning or evening. If I skip them then I get quite
> stiff within a couple of days.
>
>
>
>
> [/B]

Is it a small enough set that you could post what the exercises are?

I'm sure a few people here would appreciate some effective back
protection exercises.


--
onewheeldave - Semi Skilled Unicyclist

"He's also been known to indulge in a spot of flame juggling - but it's
the Muni that really fires him up."

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chirokid
August 28th 03, 03:27 AM
> You have my sympathy Mikefule. [/B]
>
> >
> >
> > Mikefule, you also have my sympathy. A back in the pain can be one
> > of the worst pains you ever experience.
> >
> >
> >
> > > "Treat Your Own Back" by Robin McKenzie, ISBN 0-9597746-6-1. It
> > > was recommended to me by my physiotherapist after I slipped a disk
> > > in 1995. It's quite expensive for a very thin volume, but I'm
> > > sure it's saved me a lot of pain. [/B]
> > >
> > > >
> > > >
> > > > Danny Colyer is right. This book by McKenzie is wonderful. I
> > > > am a Doctor of Chiropractic (we fix patient's backs all day
> > > > long), and I teach McKenzie stretches to several patients every
> > > > day. He did the whole back industry a great service by writting
> > > > this book.
> > > >
> > > >
> > > >
> > > > > 8 years later I still religiously perform a set of back
> > > > > stretching exercises every morning or evening. If I skip them
> > > > > then I get quite stiff within a couple of days. [/B]
> > > >
> > > >
> > > > Danny, if this is the case, I would suggest you locate a good
> > > > Chiropractor. The combination of re-aligning your spine,
> > > > through Chiropractic care and doing your daily stretches should
> > > > give you a better result. Getting stiff within 2 days of
> > > > skipping your stretches tells me you, in all likelyhood, need
> > > > the addition of Chiropractic care to you "Healthy Back Plan".
> > > >
> > > >
> > > > Plus, you could ride your unicycle further, harder and in less
> > > > pain! :) That got us back on topic. --chirokid--



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chirokid

"Unicycling can make you proud then humble in very quick succession."
Mikefule

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chirokid
August 28th 03, 03:29 AM
Whoops, I guess I still have not figured out this MULTIPLE Quote in one
post thingy yet. I'll keep trying to learn.

I'm a back doc, not a computer guru. --chirokid--


--
chirokid

"Unicycling can make you proud then humble in very quick succession."
Mikefule

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GILD
August 28th 03, 09:41 AM
chirokid wrote:
> *Whoops, I guess I still have not figured out this MULTIPLE Quote in
> one post thingy yet. --chirokid-- *


hi there

i can't remeber who told me this but it works a charm
if u want to do multiple posts, u can either remember the whole sequence
of [url/#^}--blahbblah]^[email protected]_ u have to type or cheat

cheating is easier
once u decide to reply to a thread using multiple quotes, press control
and 'n'
this (i never knew) opens a copy of the page that u're on in a new
window
file-new-window does the same thing (i'm in IE here, dont get
complicated now)
in the original window, click on 'quote' at the applicable post
go to the new window and click on 'quote' at the other post u want to
quote

back to the first window,trim the quote, add your bit and then go to the
new window, trim the quoted bit to your needs and highlight/copy/paste
it below your first quote and reply in the original window
u can now hit 'back' on the second window in case u need to do another
quote

and so on

just spreading the joy...


--
GILD - Waffle-tosser

The only difference between me and a madman is that i'm not mad.
Pablo Picasso

'this will only take a minute...'
(http://www.burmacampaign.org.uk/actions/un.htm/)

JUST SAY 'KNOW'!

Namaste!
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Mikefule
August 28th 03, 12:59 PM
Just for the record, I didn't invent the Constant Footspeed Hypothesis.
I vaguely recall the first reference to it that I saw was by Roger - on
that someone quoted Roger in this forum. I did, however, use it as a
basis for several informal experiments. The results seemed to suggest
it is only a valid hypothesis in the 'mid range' or for adjacent vlaues
of wheel size or crank length. For extremes, common sense says it
couldn't possibly be valid.


--
Mikefule - Roland Hope School of Unicycling

"Our greatest glory is not in never falling, but in rising every time we
fall."
Confucius
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Danny Colyer
August 28th 03, 08:55 PM
chirokid dodgily quoted:
> > > > > This book by McKenzie is wonderful.
<snip>
> > > > > He did the whole back industry a great service by
> > > > > writting this book.

It's good to be backed up by an expert :-)

> > > > > Danny, if this is the case, I would suggest you locate a good
> > > > > Chiropractor.

I've been told that before. But I don't believe chiropracty is
available on the NHS, and I'm a cheapskate. I've only had a few days of
discomfort in the last 7 years, so I'm happy enough.

> > > > > Plus, you could ride your unicycle further, harder and in less
> > > > > pain! :) That got us back on topic. --chirokid--

The only times I've ever had discomfort while unicycling have been from
riding with a twisted saddle (easily corrected) or from riding on a
camber with low tyre pressure (lots of twisting, again easily
corrected). I tend to twist to the left, and holding onto the front of
the saddle with my left hand helps enormously in preventing that.

I should ride more and harder to strengthen my abs, though, which have
been getting progressively saggier over the last few years :-(

(According to Zod I'm exactly 1 week younger than Kris Holm, so his
should be that bit saggier still. But I think he cheats by yiking a lot
more than I do).

--
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nosabe332
August 29th 03, 03:31 AM
there've been so many tangents i feel like i've stepped into geometry
class.... ahem..

anyway i wanted to bring up the crank ratio topic. a 24" with 170s is
incredibly inefficient at moving without perspiring. i considered 150s
a while ago, but nothing happened of it.. after reading Mikefule's
essay, i again consider new cranks. being back in urban berkeley, i
wonder if getting 102s would be a good option. i don't think there is
much mountainous terrain here, and i can probably still MUni if i so
desired. i would probably use the machine as a convenient transport..
which begs another question of tire type.. should i stick with my
knobby? or get a hookworm? or something else? how many times i've
asked that question, i'll never know.


--
nosabe332 - can't.. go slow enough!

-Eric

'well turn on something... i'm starting to think!'
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Mikefule
August 29th 03, 07:38 AM
102s are good on a real 24. On a 24 with a big tyre (effectively a 26)
you might find them a bit short. You gain on speed but lose on
control.

110s are a good compromise. Anything longer than 125 on a 24 makes it a
real tractor.


--
Mikefule - Roland Hope School of Unicycling

"Our greatest glory is not in never falling, but in rising every time we
fall."
Confucius
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