Lowest Possible Gears

yup. reminds of that patsy cline song: SEDA ...
i'm an unrepentant ivy league bohemian. it makes my day to ride out
into 'my' upper class nab in the morning and slowly past a blue haired
old hog whose been shouting 'ura unrepentant ivy league bohemian' at
me, on the verge with a plastic bag on her hand scraping hot dogshit
off the grass and after breakfast to boot. divinity deleted.
I 'took' a wonderful fascinating class in microbiology and...

Quoted message said:

On Tue, 10 Apr 2007 20:12:29 -0500, A Muzi <[email hidden]>

Quoted message said:

-snip-

Quoted message said:

<[email hidden]> wrote:
> Try walking up
> one of those Colorado mountains you live near at 3-4 mph while pushing
> a loaded touring bike and then ride up the same stretch at 4 mph.
> Biking up is easier. You may be correct that you actually use less
> energy walking and pushing, but it won't feel like it.

Quoted message said:

Quoted message said:

Sorry, but I'm not following the logic.
You seem to be saying that "biking up is easier" but it uses more
energy?
As for not feeling like it, walking is if anything more natural than
the circular raise-lower cycle of the pedal. Pedaling at such low
speeds turns a modest hiking slope into a steep stairway.
It might feel better in terms of accomplishment and our natural RBT
prejudice that feet are meant to pedal, not to walk, but if it uses
more energy, it will feel harder, not easier.
Note where such logic would eventually lead--a 10 x 34 would make
riding up a hill even "easier", despite requiring twice as many leg
lifts at half the speed. The lower limit for useful uphill bicycle
gearing for normal riders is somewhere down around walking speed.
This is why we just don't see much of the ultra-low gearing setups
that people occasionally wish for on RBT. Bicyclists will try almost
anything, but the extremes usually filter themselves out quickly.

Quoted message said:

Quoted message said:

When the North Vietnamese were trundling military supplies south
through mountain trails on heavily-laden bikes, they pushed instead of
trying to fit ultra-low gearing.

Quoted message said:

Quoted message said:

I'm open, however, to correction. Does anyone actually have a 20 x 38
on a 700c or MTB? If so, try riding up a trail steep enough to require
it for a few hundred yards one day, and then try pushing the bike up
the same trail again.

Quoted message said:

Quoted message said:

Years ago, I watched a pair of ultra-low geared MTB's spinning
furiously up a steep slope in the Wet Mountains and was surprised to
find that I was overtaking them on foot.

Quoted message said:

Quoted message said:

Beginning trials riders often re-discover this sort of thing. There's
a limit to how low you can usefully gear a motorcycle, given the
engine characteristics, and the stock trials machines are usually
close to it.

Quoted message said:

Quoted message said:

Same thing with the human engine--gear a bicycle too low for too steep
a climb, and you work harder than you would just walking. You'd have
to put a hobble on the hiker's boots to even things up. The Fargo
Street Hill climbers use surprisingly high gearing for their ~30%
grade.

Quoted message said:

heh heh great image! We used a photo of Vietcong pushing 400lbs of gear
on a Peugeot though the jungle in a Peugeot ad once. lotsa flak. [see
also 'Bicycles in War']

Quoted message said:

In my experience, most cyclists will prefer a possibly 'inefficient' low
gear to walking. It's a psychological barrier most people simply do not
like to cross. YMMV. I do not have an opinion on what's 'best', having
done both.

Dear Andrew,

I think that we agree about the psychological barrier--most posters on
RBT would automatically strain harder rather than get off and push a
bike, and few of us will give up trying if a pretty girl is watching
or other posters are reading what we write.

But I'm still open to correction.

I just have trouble seeing how moving my feet three feet through an
unnatural high-stepping circle in order to roll myself and my load
forward three feet is going to be easier than ordinary walking.

Walking a bike up a steep hill is not more efficient than riding it,
the inherent efficiencies of cycling still apply. You may be able to
walk faster up a hill than some one cycling up in granny gear, but
you'll be using more energy (if all things are assumed equal). And the
reason it sometimes feels easier to walk is because when you jump off
the bike and start walking you switch to a subtly different muscle
group. One that hasn't been working hard in pedaling that bike up
hill.

I have find that there are limits to pedaling over walking and there
usually around where I'm expending a whole bunch of effort and energy
just keeping the front wheel down. A couple of hills near me run over
25% incline. If I could change the geometry of the bike as I head up
these hills I know I could ride them. Another limit is grip and
terrain where a sure foot would be more efficient than a slipping rear
tyre.

Laters,

Marz

<[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

On Tue, 10 Apr 2007 20:12:29 -0500, A Muzi <[email hidden]>

Quoted message said:

-snip-

Quoted message said:

<[email hidden]> wrote:
> Try walking up
> one of those Colorado mountains you live near at 3-4 mph while pushing
> a loaded touring bike and then ride up the same stretch at 4 mph.
> Biking up is easier. You may be correct that you actually use less
> energy walking and pushing, but it won't feel like it.

Quoted message said:

Sorry, but I'm not following the logic.
You seem to be saying that "biking up is easier" but it uses more
energy?
As for not feeling like it, walking is if anything more natural than
the circular raise-lower cycle of the pedal. Pedaling at such low
speeds turns a modest hiking slope into a steep stairway.
It might feel better in terms of accomplishment and our natural RBT
prejudice that feet are meant to pedal, not to walk, but if it uses
more energy, it will feel harder, not easier.
Note where such logic would eventually lead--a 10 x 34 would make
riding up a hill even "easier", despite requiring twice as many leg
lifts at half the speed. The lower limit for useful uphill bicycle
gearing for normal riders is somewhere down around walking speed.
This is why we just don't see much of the ultra-low gearing setups
that people occasionally wish for on RBT. Bicyclists will try almost
anything, but the extremes usually filter themselves out quickly.

When the North Vietnamese were trundling military supplies south
through mountain trails on heavily-laden bikes, they pushed instead of
trying to fit ultra-low gearing.

I'm open, however, to correction. Does anyone actually have a 20 x 38
on a 700c or MTB? If so, try riding up a trail steep enough to require
it for a few hundred yards one day, and then try pushing the bike up
the same trail again.

Years ago, I watched a pair of ultra-low geared MTB's spinning
furiously up a steep slope in the Wet Mountains and was surprised to
find that I was overtaking them on foot.

Beginning trials riders often re-discover this sort of thing. There's
a limit to how low you can usefully gear a motorcycle, given the
engine characteristics, and the stock trials machines are usually
close to it.

Same thing with the human engine--gear a bicycle too low for too steep
a climb, and you work harder than you would just walking. You'd have
to put a hobble on the hiker's boots to even things up. The Fargo
Street Hill climbers use surprisingly high gearing for their ~30%
grade.

heh heh great image! We used a photo of Vietcong pushing 400lbs of gear
on a Peugeot though the jungle in a Peugeot ad once. lotsa flak. [see
also 'Bicycles in War']

In my experience, most cyclists will prefer a possibly 'inefficient' low
gear to walking. It's a psychological barrier most people simply do not
like to cross. YMMV. I do not have an opinion on what's 'best', having
done both.

Dear Andrew,

I think that we agree about the psychological barrier--most posters on
RBT would automatically strain harder rather than get off and push a
bike, and few of us will give up trying if a pretty girl is watching
or other posters are reading what we write.

But I'm still open to correction.

(clip) I just have trouble seeing how moving my feet three feet through an
unnatural high-stepping circle in order to roll myself and my load forward
three feet is going to be easier than ordinary walking. (clip)

^^^^^^^^^^^^^^^^^^
Carl, the circle through which you move your feet is exactly the same
whether you're spinning on a level road or chugging up a steep hill. If
your bike is properly designed and adjusted for the former, it will be
correct for the latter. Low gearing on a bike is equivalent to using a crow
bar or a winch for moving a heavy load. The arc through which your feet
move must be drawn relative to your body, not to the ground. Otherwise,
walking on a moving train would be really weird.

carlfogel said:

It would probably be less work to get off and push the bike, avoiding
the transmission loss and the fuss of balancing while presumably
struggling uphill at 95 rpm at walking speed.

Pushing would also eliminate the problem of stalling and toppling when
the front tire hits a bump on the road.

This seems logical, but with a heavily loaded bike it's easier
to stay on the bike and pedal, at least for awhile.

Matt O.

Matt O'Toole said:

carlfogel said:

It would probably be less work to get off and push the bike, avoiding
the transmission loss and the fuss of balancing while presumably
struggling uphill at 95 rpm at walking speed.

Pushing would also eliminate the problem of stalling and toppling when
the front tire hits a bump on the road.

This seems logical, but with a heavily loaded bike it's easier
to stay on the bike and pedal, at least for awhile.

Matt O.

Dear Matt,

Quite likely there are short stretches where "at least for a while"
might cover things through coasting, convenience in mounting and
dismounting, perceived comfort, and pure psychological prejudice.

But if your feet are moving 3 feet in an unnatural high-stepping
circle (345 mm = 13.6 inches) to move everything forward 3 feet, it's
hard to see how it's going to be easier in terms of less physical
effort than walking.

At the ~60 rpm that studies suggest is the most efficient cadence, a
24 front x 34 rear with a 2124 mm 700c and a 172.5 mm crank is
chugging up the hill at only 3.35 mph, while a 20 front x 38 rear is
doing all of 2.51 mph.

In a thread with many comments about how most (though not all) riders
lower their cadence on hills, Robert Chung mentioned that studies
indicate maximum efficiency is around 50~60 rpm and drops as cadence
increases:

http://groups.google.com/group/rec.bicycles.tech/msg/f206ae932369120f

Somehow I doubt that anyone is going to build a pedal-powered
cog-railway next to a long stairway that somehow makes it "easier"
than walking.

But maybe someone will explain how the physics and physiology make it
easier to push pedals down around a 1-to-1 overall pedal to rear-wheel
ratio. If I'm mistaken, there must be an explanation.

Cheers,

Carl Fogel

On 11 Apr 2007 07:07:10 -0700, "[email hidden]"
<[email hidden]> wrote:

[snip]

Quoted message said:

Ordinary walking? That is the point I made before. Pushing a 60-100
pound bike up a steep mountain road is not ordinary walking. It takes
far more effort and trouble to push/walk the bike than to ride if your
gear is low enough. Have you ever tried pushing a loaded touring bike
up one of those Colorado mountains you claim to live near? Even the
mild ones of 7% grade. You are bending forward, your achilles tendons
are stretched from bending forward, you are on your toes pushing
forward. Its not ordinary walking.

Carl, someday instead of taking your daily 15 mile trail ride through
the thorns, get a loaded touring bike from someone. Just the bike and
panniers. Put a gallon jug of water in each of the four panniers. 32
pounds total. A light load for loaded touring. Then take this bike
and ride a mile up one of the mountains nearby. Then walk a mile
pushing the bike up the mountain. See which is easier on your legs
and body.

Dear Russell,

Do you have any physical explanation for your theory that pushing
pedals in a large circle is easier than walking when the load and
grade are enough to require a 1-to-1 ratio between pedal motion and
rear wheel travel?

Cheers,

Carl Fogel

On 11 Apr 2007 08:25:15 -0700, "Marz" <[email hidden]> wrote:

[snip]

Quoted message said:

Walking a bike up a steep hill is not more efficient than riding it,
the inherent efficiencies of cycling still apply.

[snip]

Dear Marz,

At a 1-to-1 ratio between pedal and rear wheel travel, what are the
inhere efficiencies of cycling?

Cheers,

Carl Fogel

Leo Lichtman said:

<[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

On Tue, 10 Apr 2007 20:12:29 -0500, A Muzi <[email hidden]>

Quoted message said:

-snip-
> <[email hidden]> wrote:
>> Try walking up
>> one of those Colorado mountains you live near at 3-4 mph while pushing
>> a loaded touring bike and then ride up the same stretch at 4 mph.
>> Biking up is easier. You may be correct that you actually use less
>> energy walking and pushing, but it won't feel like it.

[email hidden] wrote:
> Sorry, but I'm not following the logic.
> You seem to be saying that "biking up is easier" but it uses more
> energy?
> As for not feeling like it, walking is if anything more natural than
> the circular raise-lower cycle of the pedal. Pedaling at such low
> speeds turns a modest hiking slope into a steep stairway.
> It might feel better in terms of accomplishment and our natural RBT
> prejudice that feet are meant to pedal, not to walk, but if it uses
> more energy, it will feel harder, not easier.
> Note where such logic would eventually lead--a 10 x 34 would make
> riding up a hill even "easier", despite requiring twice as many leg
> lifts at half the speed. The lower limit for useful uphill bicycle
> gearing for normal riders is somewhere down around walking speed.
> This is why we just don't see much of the ultra-low gearing setups
> that people occasionally wish for on RBT. Bicyclists will try almost
> anything, but the extremes usually filter themselves out quickly.
>
> When the North Vietnamese were trundling military supplies south
> through mountain trails on heavily-laden bikes, they pushed instead of
> trying to fit ultra-low gearing.
>
> I'm open, however, to correction. Does anyone actually have a 20 x 38
> on a 700c or MTB? If so, try riding up a trail steep enough to require
> it for a few hundred yards one day, and then try pushing the bike up
> the same trail again.
>
> Years ago, I watched a pair of ultra-low geared MTB's spinning
> furiously up a steep slope in the Wet Mountains and was surprised to
> find that I was overtaking them on foot.
>
> Beginning trials riders often re-discover this sort of thing. There's
> a limit to how low you can usefully gear a motorcycle, given the
> engine characteristics, and the stock trials machines are usually
> close to it.
>
> Same thing with the human engine--gear a bicycle too low for too steep
> a climb, and you work harder than you would just walking. You'd have
> to put a hobble on the hiker's boots to even things up. The Fargo
> Street Hill climbers use surprisingly high gearing for their ~30%
> grade.

heh heh great image! We used a photo of Vietcong pushing 400lbs of gear
on a Peugeot though the jungle in a Peugeot ad once. lotsa flak. [see
also 'Bicycles in War']

In my experience, most cyclists will prefer a possibly 'inefficient' low
gear to walking. It's a psychological barrier most people simply do not
like to cross. YMMV. I do not have an opinion on what's 'best', having
done both.

Dear Andrew,

I think that we agree about the psychological barrier--most posters on
RBT would automatically strain harder rather than get off and push a
bike, and few of us will give up trying if a pretty girl is watching
or other posters are reading what we write.

But I'm still open to correction.

(clip) I just have trouble seeing how moving my feet three feet through an
unnatural high-stepping circle in order to roll myself and my load forward
three feet is going to be easier than ordinary walking. (clip)

^^^^^^^^^^^^^^^^^^
Carl, the circle through which you move your feet is exactly the same
whether you're spinning on a level road or chugging up a steep hill. If
your bike is properly designed and adjusted for the former, it will be
correct for the latter. Low gearing on a bike is equivalent to using a crow
bar or a winch for moving a heavy load. The arc through which your feet
move must be drawn relative to your body, not to the ground. Otherwise,
walking on a moving train would be really weird.

Dear Leo,

You're moving your feet around a high-stepping circle. With a 172.5 mm
crank, you're climbing the equivalent of 13.6 inch steps.

As I keep asking, what is the inherent efficiency of a 1-to-1 pedal to
rear wheel travel that makes it superior to walking?

Down at that gearing, you have no apparent mechanical advantage and
your legs are bent so far at the knee at the top of the pedal stroke
that you would seem to be at a considerable disadvantage.

No one disputes the advantages of normal gearing on gentler slopes,
where bicycles trade force for distance. But at 1-to-1 pedal and rear
wheel travel, where is the advantage?

Cheers,

Carl Fogel

Clive George said:

<[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Carl, you can easily maintain your balance and still ride up hills at
less than 4 mph.

Seconded. We regularly ride up hills on a tandem at 2.5-3 mph.

cheers,
clive

Dear Clive,

The question is whether you are working harder to do so than you would
be working if you got off and pushed your bike uphill on foot.

I keep seeing everything in this thread except an explanation of the
physics of how pushing pedals at a 1-to-1 pedal-to-rear-wheel-movement
ratio in a 345 mm circle is going to require less effort than walking.

Cheers,

Carl Fogel

Carl Fogel said:

Quoted message said:

Quoted message said:

Carl, you can easily maintain your balance and still ride up hills
at less than 4 mph.

Quoted message said:

Quoted message said:

Seconded. We regularly ride up hills on a tandem at 2.5-3 mph.

Quoted message said:

The question is whether you are working harder to do so than you
would be working if you got off and pushed your bike uphill on foot.

Quoted message said:

I keep seeing everything in this thread except an explanation of the
physics of how pushing pedals at a 1-to-1
pedal-to-rear-wheel-movement ratio in a 345 mm circle is going to
require less effort than walking.

That isn't the point as I see it. You can't say "I rode all the way"
if you get off and walk. To make pedaling motion equal to rear wheel
motion with 175mm cranks would require a 20t Chainwheel to 38 tooth
rear sprocket. I don't recall seeing anyone ride any distance with
such a gear ratio on any hill where it might be needed.

Walking is also easier for the relatively effortless motion of the
unloaded forward stride beside the arbitrary stride, but then you
can't say "I rode all the way".

Jobst Brandt

<[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

On 11 Apr 2007 08:25:15 -0700, "Marz" <[email hidden]> wrote:

[snip]

Quoted message said:

Walking a bike up a steep hill is not more efficient than riding it,
the inherent efficiencies of cycling still apply.

[snip]

Dear Marz,

At a 1-to-1 ratio between pedal and rear wheel travel, what are the
inhere efficiencies of cycling?

You're neglecting other's points about ergonomics. One's choices are either
leaning over far too much in order to push, or walking naturally while
carrying one's bike. A loaded tourer kind of precludes the latter.

It's not all about the gearing or the progress made per revolution!!!

Greg
--
Ticketbastard tax tracker:
http://ticketmastersucks.org/tracker.html

Dethink to survive - Mclusky

RIGHT! a complex subject. for the past 8 years, i rode more time/
distance/intervals than walked but walked strenuously for short
distances each day.
I moved to the beach. I did a short run up to running on the beach and
tore an ankle muscle. i was unaware of it. I could no longer walk!! i
started a movement to jog after stretching and stopped after a step.
two months later after ankle excercise, i'm kinda back.
yawl know this is true. the excellent armstrong/carmichael workout
book remember?
then the brevet riders...
quantifying spin v walk?????
i can qualify it tho. every tale i've heard personally about how I
RODE OVER THE ROCKY MOUNTAINS was a tall tale. always the news came
in: he gotta ride. not walk not spin but he gotta ride pushing the hd
touring load is cool. itsa great pack animal, no [censored].

I'd rather ride this up a hill than push it.

http://www.eastonbike.com/PRODUCTS/WHEELS/wheel_riders-anthony.html

Carl Sundquist said:

I'd rather ride this up a hill than push it.

http://www.eastonbike.com/PRODUCTS/WHEELS/wheel_riders-anthony.html

Maybe with the gears on this bike:
http://www.pbase.com/coaster/image/76287256
(Kind of cut off, but follow the angle of the timing chain.)

Owww... my knees hurt just looking at that.0

Jeff

In article
<[email hidden]>,

cmcanulty said:

Here are some further thoughts on why I need a lower gear: 1)In our
local bike group I can always get up steeper hills than other riders
even when they are stronger, when I lend my bike others find the hills
much easier 2)However the problem isn't that I have to spin fast or
fall over-I think a lower gear is needed when I have to slow down my
cadence as it is too hard to pedal. I normally spin at 90 to 100 rpm.
If I got such a low gear that I was spinning faster than that when
ascending a steep hill I would be at the lowest practical gear. But
now as I go up a long steep hill I have to gradually lower my cadence.
If I had the optimal gear I would be able to spin at 90-100 on the
steepest hills with a loaded bike. I have often heard the argument
that with a really low gear you have to turn the pedals faster than is
possible or comfortable, but I think this isn't actually the case. I
have never seen someone be able to keep up even their normal cadence
on a very steep long hill, negating this idea at least for the great
majority of riders.

I am about the slowest bike out on the road; almost
everyone passes me. The one exception is a stiff little
0.5 km grade at the end of 1.5 km of lesser grade where
I drop into a 24/23 and keep up with many double chain
wheel bikes that blow past me in other circumstances.
Cadence around 70.

For example, on switch back turns with exaggerated pitch
on the inside, I ride the inside while others take
the outside track for a considerable gain in distance.

--
Michael Press

<[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Clive George said:

<[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Carl, you can easily maintain your balance and still ride up hills at
less than 4 mph.

Seconded. We regularly ride up hills on a tandem at 2.5-3 mph.

The question is whether you are working harder to do so than you would
be working if you got off and pushed your bike uphill on foot.

I keep seeing everything in this thread except an explanation of the
physics of how pushing pedals at a 1-to-1 pedal-to-rear-wheel-movement
ratio in a 345 mm circle is going to require less effort than walking.

I'm not sure you can directly compare in the way you're doing. When pushing,
the distance travelled by my feet is rather smaller than the big pedal
circle - I move them significantly less. So I may well use a lower force on
the pedal, but for a larger distance (I don't honk on the tandem).

I'm not sure you're going to get an answer from simple-minded physics, since
ergonomics comes into play. You need to go out and actually measure some
stuff - and even then it's a bit subjective. Eg I know my calves hurt after
pushing a heavy bike up hill. Where does pain come into your definition of
"less effort"?

cheers,
clive

Matt O'Toole said:

carlfogel said:

It would probably be less work to get off and push the bike, avoiding
the transmission loss and the fuss of balancing while presumably
struggling uphill at 95 rpm at walking speed.

Pushing would also eliminate the problem of stalling and toppling when
the front tire hits a bump on the road.

Quoted message said:

This seems logical, but with a heavily loaded bike it's easier
to stay on the bike and pedal, at least for awhile.

Especially with cleated shoes.

--

John ([email hidden])

Carl Sundquist said:

I'd rather ride this up a hill than push it.

http://www.eastonbike.com/PRODUCTS/WHEELS/wheel_riders-anthony.html

I hope he's got good brakes for that thing. Can you imagine riding it up
this?

http://gklose.de/gallery/albums/album29/aac.jpg

(note bicyclists on left side of picture)

--

John ([email hidden])

Quoted message said:

The question is whether you are working harder to do so than you would
be working if you got off and pushed your bike uphill on foot.

I keep seeing everything in this thread except an explanation of the
physics of how pushing pedals at a 1-to-1 pedal-to-rear-wheel-movement
ratio in a 345 mm circle is going to require less effort than walking.

First of all, consider the 1-to-1 pedal-to-rear-wheel-movement ratio of
pedaling vs. walking, at a constant and equivalent speed, on a _flat_
surface. When walking, one uses energy to move every step forward. Each
time you take a step you are pushing your weight forward.

On a bike, pedaling is only necessary to counter forces related to air
drag and mechanical friction. This is inherent efficiency of cycling.

As for inclines: When going uphill, the cyclist and the walker both have
to exert additional energy to overcome gravity. On slight inclines, the
additional force needed is negligible, so the cyclist is still at an
advantage. But people here seem to have doubts about the cyclist's
advantage when the incline is steeper.

So the question is actually:

At what degree of incline, if any, is a cyclist less efficient pedaling
than he would be by walking his bike?

I don't know the answer. My gut feeling is "none", but perhaps somebody
with more knowledge of this can shed the light.

--
K.

Lang may your lum reek.

Quoted message said:

Carl Fogel said:

Quoted message said:

> Carl, you can easily maintain your balance and still ride up hills
> at less than 4 mph.

Quoted message said:

Quoted message said:

Seconded. We regularly ride up hills on a tandem at 2.5-3 mph.

Quoted message said:

The question is whether you are working harder to do so than you
would be working if you got off and pushed your bike uphill on foot.

Quoted message said:

I keep seeing everything in this thread except an explanation of the
physics of how pushing pedals at a 1-to-1
pedal-to-rear-wheel-movement ratio in a 345 mm circle is going to
require less effort than walking.

That isn't the point as I see it. You can't say "I rode all the way"
if you get off and walk. To make pedaling motion equal to rear wheel
motion with 175mm cranks would require a 20t Chainwheel to 38 tooth
rear sprocket. I don't recall seeing anyone ride any distance with
such a gear ratio on any hill where it might be needed.

Walking is also easier for the relatively effortless motion of the
unloaded forward stride beside the arbitrary stride, but then you
can't say "I rode all the way".

Jobst Brandt

Dear Jobst,

I tend to agree with you and Andrew that there's a strong
psychological factor.

And like you, I'm skeptical of seeing many places where the ultra-low
gearing is useful for normal riders. But to be fair, enough cargo can
make a very low gear useful. It's hard, however, to see any gearing
that will provide a real advantage over pushing on foot.

If there really is some advantage, then it should be possible to build
a pedal-powered cog railway next to a long flight of stairs that will
make it easier to get to the top.

For those curious about the details, for a 175 mm crank and a 2100 mm
circumference 700c tire, my spreadsheet indicates a pedal-to-tire
movement ratio of 1.00519, effectively a 1-to-1 ratio.

At a cadence of 60 rpm, the bicycle would be moving at 2.47 mph.

At the same cadence, someone walking will move at the same speed with
a shortened stride of 3 feet, 7.5 inches. (Given a steep hill or a
heavily loaded bicycle, it's normal for strides to shorten--we gear
down, so to speak, to suit the situation.)

I imagine that in some parallel universe, posters on a hiking
newsgroup are earnestly insisting that it cannot possibly be easier to
pedal a mountain bike up a gentle grade than to walk up it because of
the inherent advantages of walking, because hiking shoes would slip
off the pedals, and because that strange round motion of the feet
would undoubtedly be very painful.

Besides, they couldn't say "I hiked all the way."

Cheers,

Carl Fogel