Clipless pedals no more efficient than flat?

On Wed, 12 Aug 2020 17:59:20 -0700 (PDT), Frank Krygowski
wrote:

On Wednesday, August 12, 2020 at 8:52:35 PM UTC-4, AMuzi wrote:
On 8/12/2020 6:22 PM, John B. wrote:
On Thu, 13 Aug 2020 06:01:07 +0700, John B.
wrote:

On Wed, 12 Aug 2020 14:54:14 -0700 (PDT), jbeattie
wrote:

On Wednesday, August 12, 2020 at 9:24:50 AM UTC-7, Frank Krygowski wrote:
On 8/11/2020 11:28 PM, jbeattie wrote:
On Tuesday, August 11, 2020 at 6:03:46 PM UTC-7, Frank Krygowski wrote:
On 8/11/2020 6:05 PM, jbeattie wrote:

I certainly pulled up or across the pedal when track racing, and if I pulled out, it could be catastrophic -- and thus double straps and later clipless (some racers used clipless and straps). Foot retention is important when sprinting and climbing out of the saddle. https://www.tandfonline.com/doi/full...0.2020.1769201

It's a shame they didn't test stiff soled cycling shoes with toe clips.
For a long time those were the default choice for avid cyclists. They're
still my choice for long rides.

But I'll point out, that paper (apparently) did not measure efficiency.
The power improvements were huge (9.7???8.7% power gain by adding toe
clips to soft shoes, and 16.6???10.2% gain with rigid shoes and
clipless). On a five percent grade, that corresponds to a very
noticeable increase in speed. If those gains were due to lack of
efficiency of soft soles, those soles must have been soaking up a hell
of a lot of power. That means they should get very hot.

We can discuss this, but I suspect a lot of the gains measured were due
to the "red bikes are faster" effect. Testers were probably
preconditioned to think toe clips help a lot, and REAL cycling shoes and
clipless are what professionals use. That's a recipe for a powerful placebo.

If not that, then what made the power difference? Where would the power
have been previously lost? We should be able to talk about that in detail.

And shoes can make a big difference. I remember going from Detto, Vittoria or Italia (they all blended together) bicycling/bowling shoes of yore with little steel stiffeners and nail on cleats to Duegis with wood soles and bolt-on plastic cleats. https://www.classicsteelbikes.com/wp...-1-600x400.jpg That was huge -- like going from Michelin 50s to Vittoria CGs (I never rode silks). That was probably the single biggest component improvement I ever had.

Again, we should be able to analyze the exact source of the improvement.
The shoes are not a source of power; they are a simple device for
transmitting power from your foot to the pedal.

I don't doubt that some changes allow better biomechanics and thus
better power output. But it's hard for me to see how shoes do that.


A couple of things: (1) your ankle is not a spring, dropping as the sole flexes. Old cycling shoes were really like bowling shoes and not very stiff. (2) Deeper, more secure cleats -- for better or worse. It was not a subtle change for me at all. Others agree: http://stevetilford.com/2016/05/26/cycling-shoes-2/ YMMV.

I'm not surprised that there are people who rhapsodize about shoes. And
I know that certain shoes are more or less comfortable for certain
riders, some shoes have better closure systems, etc. But to return to
_technical_ discussion about power transfer:

Again, the paper you linked could have tested stiff soled shoes with toe
clips. Unfortunately it didn't.

And it's true that "stiff" isn't a binary condition. But aside from
commuting or utility riding, all the cycling shoes I've used (since Bata
Bikers came on the scene) have seemed pretty stiff to me. Not as stiff
as wooden soles, but then, nobody here has identified a mechanism for
power loss through a sole that's a little less stiff.

Thought experiment (since you mention springs): Place a spring with a
high stiffness (say, 100 pounds per inch) on a bike pedal. Place a ten
pound weight on that spring. It will sag 1/10 inch. What's the force on
the pedal?

Repeat with a spring that's less stiff (say, 50 pounds per inch). Place
the same ten pound weight on that spring. It will sag 2/10 inch. What's
the force on that pedal?

The answer is the same in both cases: Pedal force is ten pounds.

It seems pretty simple to me. The power used flexing the sole is not transmitted into the pedal. It is wasted energy. A sloppy shoe-pedal interface is lossy. No? Did you not cinch up your toe-straps before a climb or a sprint?

Rather than trying thought experiments, go and try a pair of stiff shoes in a clipless pedal system. Actually experience the modern world before making grand pronouncement about how nothing makes a difference. And BTW, "pulling up" is not a myth -- as anyone who has pulled out in track sprint can tell you. I almost pulled out of my left shoe last night humping up a hill and had to reach down and cinch up the ratchet -- or if I were you, stop and retie my shoe.

-- Jay Beattie.


If there is a substantial loss of power through "flexing the sole" why
aren't runners wearing hard soled shoes? My guess is that an Olympic
class sprinter is applying at least as much, and possibly more, force
against the ground than a cyclist applies against the pedals. Abebe
Bikila of Ethiopia won an Olympic gold medal in a world-record
2:15:16.2 running barefooted in 1960.

Further to the above, Usain Bolt in breaking the world 100m record
developed a maximum of 2619.5 watts after only 0.89 seconds of the
race.

Not wearing hard soled shoes :-)
--
Cheers,

John B.


Then again Roger Bannister and runners of his era and before
ran in 'running flats', thin very light leather shoes with
leather soles.

And there's been the recent trend of barefoot running.

It may well be that, just like flat or engaged pedals,
humans adapt well to many variants. Crank length seems to be
similar as there aren't objective performance differences
despite rider perception.

Indeed, we're probably the most adaptable animal species ever.

- Frank Krygowski

Perhaps because we aren't "specialized".

A lion can run incredibly fast, about 50 MPH,for a short distance.
Because that is how he gets supper, (actually she gets supper) but
can't climb trees. A Monkey isn't very fast on the flat but scurries
up trees quickly. A human is slower then a lion in a sprint and can't
climb trees as well as the monkey but can do both.
--
Cheers,

John B.

On 8/12/2020 8:57 PM, John B. wrote:
On Wed, 12 Aug 2020 17:59:20 -0700 (PDT), Frank Krygowski
wrote:

On Wednesday, August 12, 2020 at 8:52:35 PM UTC-4, AMuzi wrote:
On 8/12/2020 6:22 PM, John B. wrote:
On Thu, 13 Aug 2020 06:01:07 +0700, John B.
wrote:

On Wed, 12 Aug 2020 14:54:14 -0700 (PDT), jbeattie
wrote:

On Wednesday, August 12, 2020 at 9:24:50 AM UTC-7, Frank Krygowski wrote:
On 8/11/2020 11:28 PM, jbeattie wrote:
On Tuesday, August 11, 2020 at 6:03:46 PM UTC-7, Frank Krygowski wrote:
On 8/11/2020 6:05 PM, jbeattie wrote:

I certainly pulled up or across the pedal when track racing, and if I pulled out, it could be catastrophic -- and thus double straps and later clipless (some racers used clipless and straps). Foot retention is important when sprinting and climbing out of the saddle. https://www.tandfonline.com/doi/full...0.2020.1769201

It's a shame they didn't test stiff soled cycling shoes with toe clips.
For a long time those were the default choice for avid cyclists. They're
still my choice for long rides.

But I'll point out, that paper (apparently) did not measure efficiency.
The power improvements were huge (9.7???8.7% power gain by adding toe
clips to soft shoes, and 16.6???10.2% gain with rigid shoes and
clipless). On a five percent grade, that corresponds to a very
noticeable increase in speed. If those gains were due to lack of
efficiency of soft soles, those soles must have been soaking up a hell
of a lot of power. That means they should get very hot.

We can discuss this, but I suspect a lot of the gains measured were due
to the "red bikes are faster" effect. Testers were probably
preconditioned to think toe clips help a lot, and REAL cycling shoes and
clipless are what professionals use. That's a recipe for a powerful placebo.

If not that, then what made the power difference? Where would the power
have been previously lost? We should be able to talk about that in detail.

And shoes can make a big difference. I remember going from Detto, Vittoria or Italia (they all blended together) bicycling/bowling shoes of yore with little steel stiffeners and nail on cleats to Duegis with wood soles and bolt-on plastic cleats. https://www.classicsteelbikes.com/wp...-1-600x400.jpg That was huge -- like going from Michelin 50s to Vittoria CGs (I never rode silks). That was probably the single biggest component improvement I ever had.

Again, we should be able to analyze the exact source of the improvement.
The shoes are not a source of power; they are a simple device for
transmitting power from your foot to the pedal.

I don't doubt that some changes allow better biomechanics and thus
better power output. But it's hard for me to see how shoes do that.


A couple of things: (1) your ankle is not a spring, dropping as the sole flexes. Old cycling shoes were really like bowling shoes and not very stiff. (2) Deeper, more secure cleats -- for better or worse. It was not a subtle change for me at all. Others agree: http://stevetilford.com/2016/05/26/cycling-shoes-2/ YMMV.

I'm not surprised that there are people who rhapsodize about shoes. And
I know that certain shoes are more or less comfortable for certain
riders, some shoes have better closure systems, etc. But to return to
_technical_ discussion about power transfer:

Again, the paper you linked could have tested stiff soled shoes with toe
clips. Unfortunately it didn't.

And it's true that "stiff" isn't a binary condition. But aside from
commuting or utility riding, all the cycling shoes I've used (since Bata
Bikers came on the scene) have seemed pretty stiff to me. Not as stiff
as wooden soles, but then, nobody here has identified a mechanism for
power loss through a sole that's a little less stiff.

Thought experiment (since you mention springs): Place a spring with a
high stiffness (say, 100 pounds per inch) on a bike pedal. Place a ten
pound weight on that spring. It will sag 1/10 inch. What's the force on
the pedal?

Repeat with a spring that's less stiff (say, 50 pounds per inch). Place
the same ten pound weight on that spring. It will sag 2/10 inch. What's
the force on that pedal?

The answer is the same in both cases: Pedal force is ten pounds.

It seems pretty simple to me. The power used flexing the sole is not transmitted into the pedal. It is wasted energy. A sloppy shoe-pedal interface is lossy. No? Did you not cinch up your toe-straps before a climb or a sprint?

Rather than trying thought experiments, go and try a pair of stiff shoes in a clipless pedal system. Actually experience the modern world before making grand pronouncement about how nothing makes a difference. And BTW, "pulling up" is not a myth -- as anyone who has pulled out in track sprint can tell you. I almost pulled out of my left shoe last night humping up a hill and had to reach down and cinch up the ratchet -- or if I were you, stop and retie my shoe.

-- Jay Beattie.


If there is a substantial loss of power through "flexing the sole" why
aren't runners wearing hard soled shoes? My guess is that an Olympic
class sprinter is applying at least as much, and possibly more, force
against the ground than a cyclist applies against the pedals. Abebe
Bikila of Ethiopia won an Olympic gold medal in a world-record
2:15:16.2 running barefooted in 1960.

Further to the above, Usain Bolt in breaking the world 100m record
developed a maximum of 2619.5 watts after only 0.89 seconds of the
race.

Not wearing hard soled shoes :-)
--
Cheers,

John B.


Then again Roger Bannister and runners of his era and before
ran in 'running flats', thin very light leather shoes with
leather soles.

And there's been the recent trend of barefoot running.

It may well be that, just like flat or engaged pedals,
humans adapt well to many variants. Crank length seems to be
similar as there aren't objective performance differences
despite rider perception.

Indeed, we're probably the most adaptable animal species ever.

- Frank Krygowski

Perhaps because we aren't "specialized".

A lion can run incredibly fast, about 50 MPH,for a short distance.
Because that is how he gets supper, (actually she gets supper) but
can't climb trees. A Monkey isn't very fast on the flat but scurries
up trees quickly. A human is slower then a lion in a sprint and can't
climb trees as well as the monkey but can do both.

meh.
'We have the Maxim and they have not.'

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

On Wed, 12 Aug 2020 21:12:35 -0500, AMuzi wrote:

On 8/12/2020 8:57 PM, John B. wrote:
On Wed, 12 Aug 2020 17:59:20 -0700 (PDT), Frank Krygowski
wrote:

On Wednesday, August 12, 2020 at 8:52:35 PM UTC-4, AMuzi wrote:
On 8/12/2020 6:22 PM, John B. wrote:
On Thu, 13 Aug 2020 06:01:07 +0700, John B.
wrote:

On Wed, 12 Aug 2020 14:54:14 -0700 (PDT), jbeattie
wrote:

On Wednesday, August 12, 2020 at 9:24:50 AM UTC-7, Frank Krygowski wrote:
On 8/11/2020 11:28 PM, jbeattie wrote:
On Tuesday, August 11, 2020 at 6:03:46 PM UTC-7, Frank Krygowski wrote:
On 8/11/2020 6:05 PM, jbeattie wrote:

I certainly pulled up or across the pedal when track racing, and if I pulled out, it could be catastrophic -- and thus double straps and later clipless (some racers used clipless and straps). Foot retention is important when sprinting and climbing out of the saddle. https://www.tandfonline.com/doi/full...0.2020.1769201

It's a shame they didn't test stiff soled cycling shoes with toe clips.
For a long time those were the default choice for avid cyclists. They're
still my choice for long rides.

But I'll point out, that paper (apparently) did not measure efficiency.
The power improvements were huge (9.7???8.7% power gain by adding toe
clips to soft shoes, and 16.6???10.2% gain with rigid shoes and
clipless). On a five percent grade, that corresponds to a very
noticeable increase in speed. If those gains were due to lack of
efficiency of soft soles, those soles must have been soaking up a hell
of a lot of power. That means they should get very hot.

We can discuss this, but I suspect a lot of the gains measured were due
to the "red bikes are faster" effect. Testers were probably
preconditioned to think toe clips help a lot, and REAL cycling shoes and
clipless are what professionals use. That's a recipe for a powerful placebo.

If not that, then what made the power difference? Where would the power
have been previously lost? We should be able to talk about that in detail.

And shoes can make a big difference. I remember going from Detto, Vittoria or Italia (they all blended together) bicycling/bowling shoes of yore with little steel stiffeners and nail on cleats to Duegis with wood soles and bolt-on plastic cleats. https://www.classicsteelbikes.com/wp...-1-600x400.jpg That was huge -- like going from Michelin 50s to Vittoria CGs (I never rode silks). That was probably the single biggest component improvement I ever had.

Again, we should be able to analyze the exact source of the improvement.
The shoes are not a source of power; they are a simple device for
transmitting power from your foot to the pedal.

I don't doubt that some changes allow better biomechanics and thus
better power output. But it's hard for me to see how shoes do that.


A couple of things: (1) your ankle is not a spring, dropping as the sole flexes. Old cycling shoes were really like bowling shoes and not very stiff. (2) Deeper, more secure cleats -- for better or worse. It was not a subtle change for me at all. Others agree: http://stevetilford.com/2016/05/26/cycling-shoes-2/ YMMV.

I'm not surprised that there are people who rhapsodize about shoes. And
I know that certain shoes are more or less comfortable for certain
riders, some shoes have better closure systems, etc. But to return to
_technical_ discussion about power transfer:

Again, the paper you linked could have tested stiff soled shoes with toe
clips. Unfortunately it didn't.

And it's true that "stiff" isn't a binary condition. But aside from
commuting or utility riding, all the cycling shoes I've used (since Bata
Bikers came on the scene) have seemed pretty stiff to me. Not as stiff
as wooden soles, but then, nobody here has identified a mechanism for
power loss through a sole that's a little less stiff.

Thought experiment (since you mention springs): Place a spring with a
high stiffness (say, 100 pounds per inch) on a bike pedal. Place a ten
pound weight on that spring. It will sag 1/10 inch. What's the force on
the pedal?

Repeat with a spring that's less stiff (say, 50 pounds per inch). Place
the same ten pound weight on that spring. It will sag 2/10 inch. What's
the force on that pedal?

The answer is the same in both cases: Pedal force is ten pounds.

It seems pretty simple to me. The power used flexing the sole is not transmitted into the pedal. It is wasted energy. A sloppy shoe-pedal interface is lossy. No? Did you not cinch up your toe-straps before a climb or a sprint?

Rather than trying thought experiments, go and try a pair of stiff shoes in a clipless pedal system. Actually experience the modern world before making grand pronouncement about how nothing makes a difference. And BTW, "pulling up" is not a myth -- as anyone who has pulled out in track sprint can tell you. I almost pulled out of my left shoe last night humping up a hill and had to reach down and cinch up the ratchet -- or if I were you, stop and retie my shoe.

-- Jay Beattie.


If there is a substantial loss of power through "flexing the sole" why
aren't runners wearing hard soled shoes? My guess is that an Olympic
class sprinter is applying at least as much, and possibly more, force
against the ground than a cyclist applies against the pedals. Abebe
Bikila of Ethiopia won an Olympic gold medal in a world-record
2:15:16.2 running barefooted in 1960.

Further to the above, Usain Bolt in breaking the world 100m record
developed a maximum of 2619.5 watts after only 0.89 seconds of the
race.

Not wearing hard soled shoes :-)
--
Cheers,

John B.


Then again Roger Bannister and runners of his era and before
ran in 'running flats', thin very light leather shoes with
leather soles.

And there's been the recent trend of barefoot running.

It may well be that, just like flat or engaged pedals,
humans adapt well to many variants. Crank length seems to be
similar as there aren't objective performance differences
despite rider perception.

Indeed, we're probably the most adaptable animal species ever.

- Frank Krygowski

Perhaps because we aren't "specialized".

A lion can run incredibly fast, about 50 MPH,for a short distance.
Because that is how he gets supper, (actually she gets supper) but
can't climb trees. A Monkey isn't very fast on the flat but scurries
up trees quickly. A human is slower then a lion in a sprint and can't
climb trees as well as the monkey but can do both.

meh.
'We have the Maxim and they have not.'

By "maxim" I assume that you mean Sir Hiram Stevens Maxim's invention
rather than the synonym for "axiom".
--
Cheers,

John B.

Frank Krygowski wrote:
On Wednesday, August 12, 2020 at 5:54:17 PM UTC-4, jbeattie wrote:
On Wednesday, August 12, 2020 at 9:24:50 AM UTC-7, Frank Krygowski wrote:
I'm not surprised that there are people who rhapsodize about shoes. And
I know that certain shoes are more or less comfortable for certain
riders, some shoes have better closure systems, etc. But to return to
_technical_ discussion about power transfer:

Again, the paper you linked could have tested stiff soled shoes with toe
clips. Unfortunately it didn't.

And it's true that "stiff" isn't a binary condition. But aside from
commuting or utility riding, all the cycling shoes I've used (since Bata
Bikers came on the scene) have seemed pretty stiff to me. Not as stiff
as wooden soles, but then, nobody here has identified a mechanism for
power loss through a sole that's a little less stiff.

Thought experiment (since you mention springs): Place a spring with a
high stiffness (say, 100 pounds per inch) on a bike pedal. Place a ten
pound weight on that spring. It will sag 1/10 inch. What's the force on
the pedal?

Repeat with a spring that's less stiff (say, 50 pounds per inch). Place
the same ten pound weight on that spring. It will sag 2/10 inch. What's
the force on that pedal?

The answer is the same in both cases: Pedal force is ten pounds.

It seems pretty simple to me. The power used flexing the sole is not
transmitted into the pedal. It is wasted energy. A sloppy shoe-pedal
interface is lossy. No? Did you not cinch up your toe-straps before a climb or a sprint?

"It seems pretty simple to me" should be a warning. Imagine Joerg
saying that about a legal issue.

To give you a hint of the complexity, you've conflated "power" and
"energy." ("Force" and "work" are other such quantities. All are
related but not identical; all are used colloquially.)

So, how would an engineer calculate - at least roughly - the energy
lost due to sole flex? It would be the product of the force applied
and the (extra) distance it moves. Seems to me we're talking a distance
of a tiny fraction of an inch, and probably a microscopic loss. As I
hinted earlier, if that energy were lost by soaking into the shoe
structure, it would be converted to heat energy. It would be detectable
by an increase in temperature. But when I commuted to work, my office
shoes never seemed to get hot!


Frank, what you are missing is that you don’t always need to waste energy
in order to not put out as much power. I dare you to put out as much power
riding barefoot as you would with shoes. Most riders with most pedals would
find their power dropping, not due to energy wastage, but just because it
would hurt to ride barefoot.

And BTW, no, I don't cinch up my straps before a climb or sprint.
I did almost no racing, so the sprints were (and still are) fun moments
on a ride with a friend. Climbs? I just climb them. When I did time
trials, I did cinch up and sometimes used racing shoes with cleats.
Did it make a difference? Well, that's the question. I have no data
that proves they did.

Rather than trying thought experiments, go and try a pair of stiff shoes
in a clipless pedal system. Actually experience the modern world before
making grand pronouncement about how nothing makes a difference.

Hey, I actually experienced a brand new bike the other day - a red
one! I could tell that red paint really made it faster! (The color
may have been "Placebo Red.")

That should indicate the problem. It's often hard to tell real benefits
from placebo benefits. That's why sciency guys do measurements and
analyze data.

And BTW, "pulling up" is not a myth -- as anyone who has pulled out in
track sprint can tell you. I almost pulled out of my left shoe last
night humping up a hill and had to reach down and cinch up the ratchet
-- or if I were you, stop and retie my shoe.

Please understand, I'm NOT saying nobody ever pulls up on a pedal. As
I've said, I do on occasion on steep climbs or fast starts - say, to
use a gap in traffic to cross a street. I do that with my slightly
loose toe clip straps. But it's such a tiny portion of my riding it
doesn't matter much.

Apparently some data indicates it may not matter much for anybody.

- Frank Krygowski

On Wednesday, August 12, 2020 at 10:36:32 PM UTC-4, Ralph Barone wrote:

Frank, what you are missing is that you don’t always need to waste energy
in order to not put out as much power. I dare you to put out as much power
riding barefoot as you would with shoes. Most riders with most pedals would
find their power dropping, not due to energy wastage, but just because it
would hurt to ride barefoot.

?? I haven't said anything in favor of riding barefoot.

- Frank Krygowski

On Thu, 13 Aug 2020 02:36:27 +0000 (UTC), Ralph Barone
wrote:

Frank Krygowski wrote:
On Wednesday, August 12, 2020 at 5:54:17 PM UTC-4, jbeattie wrote:
On Wednesday, August 12, 2020 at 9:24:50 AM UTC-7, Frank Krygowski wrote:
I'm not surprised that there are people who rhapsodize about shoes. And
I know that certain shoes are more or less comfortable for certain
riders, some shoes have better closure systems, etc. But to return to
_technical_ discussion about power transfer:

Again, the paper you linked could have tested stiff soled shoes with toe
clips. Unfortunately it didn't.

And it's true that "stiff" isn't a binary condition. But aside from
commuting or utility riding, all the cycling shoes I've used (since Bata
Bikers came on the scene) have seemed pretty stiff to me. Not as stiff
as wooden soles, but then, nobody here has identified a mechanism for
power loss through a sole that's a little less stiff.

Thought experiment (since you mention springs): Place a spring with a
high stiffness (say, 100 pounds per inch) on a bike pedal. Place a ten
pound weight on that spring. It will sag 1/10 inch. What's the force on
the pedal?

Repeat with a spring that's less stiff (say, 50 pounds per inch). Place
the same ten pound weight on that spring. It will sag 2/10 inch. What's
the force on that pedal?

The answer is the same in both cases: Pedal force is ten pounds.

It seems pretty simple to me. The power used flexing the sole is not
transmitted into the pedal. It is wasted energy. A sloppy shoe-pedal
interface is lossy. No? Did you not cinch up your toe-straps before a climb or a sprint?

"It seems pretty simple to me" should be a warning. Imagine Joerg
saying that about a legal issue.

To give you a hint of the complexity, you've conflated "power" and
"energy." ("Force" and "work" are other such quantities. All are
related but not identical; all are used colloquially.)

So, how would an engineer calculate - at least roughly - the energy
lost due to sole flex? It would be the product of the force applied
and the (extra) distance it moves. Seems to me we're talking a distance
of a tiny fraction of an inch, and probably a microscopic loss. As I
hinted earlier, if that energy were lost by soaking into the shoe
structure, it would be converted to heat energy. It would be detectable
by an increase in temperature. But when I commuted to work, my office
shoes never seemed to get hot!


Frank, what you are missing is that you don’t always need to waste energy
in order to not put out as much power. I dare you to put out as much power
riding barefoot as you would with shoes. Most riders with most pedals would
find their power dropping, not due to energy wastage, but just because it
would hurt to ride barefoot.


I really wonder. Back when I was a young lad I rode a bicycle
barefooted for much of the summer. Granted that "Summer" in upstate
New Hampshire doesn't last that long but still...
--
Cheers,

John B.

On Thursday, August 13, 2020 at 7:44:04 AM UTC+2, John B. wrote:
On Thu, 13 Aug 2020 02:36:27 +0000 (UTC), Ralph Barone
wrote:

Frank Krygowski wrote:
On Wednesday, August 12, 2020 at 5:54:17 PM UTC-4, jbeattie wrote:
On Wednesday, August 12, 2020 at 9:24:50 AM UTC-7, Frank Krygowski wrote:
I'm not surprised that there are people who rhapsodize about shoes. And
I know that certain shoes are more or less comfortable for certain
riders, some shoes have better closure systems, etc. But to return to
_technical_ discussion about power transfer:

Again, the paper you linked could have tested stiff soled shoes with toe
clips. Unfortunately it didn't.

And it's true that "stiff" isn't a binary condition. But aside from
commuting or utility riding, all the cycling shoes I've used (since Bata
Bikers came on the scene) have seemed pretty stiff to me. Not as stiff
as wooden soles, but then, nobody here has identified a mechanism for
power loss through a sole that's a little less stiff.

Thought experiment (since you mention springs): Place a spring with a
high stiffness (say, 100 pounds per inch) on a bike pedal. Place a ten
pound weight on that spring. It will sag 1/10 inch. What's the force on
the pedal?

Repeat with a spring that's less stiff (say, 50 pounds per inch). Place
the same ten pound weight on that spring. It will sag 2/10 inch. What's
the force on that pedal?

The answer is the same in both cases: Pedal force is ten pounds.

It seems pretty simple to me. The power used flexing the sole is not
transmitted into the pedal. It is wasted energy. A sloppy shoe-pedal
interface is lossy. No? Did you not cinch up your toe-straps before a climb or a sprint?

"It seems pretty simple to me" should be a warning. Imagine Joerg
saying that about a legal issue.

To give you a hint of the complexity, you've conflated "power" and
"energy." ("Force" and "work" are other such quantities. All are
related but not identical; all are used colloquially.)

So, how would an engineer calculate - at least roughly - the energy
lost due to sole flex? It would be the product of the force applied
and the (extra) distance it moves. Seems to me we're talking a distance
of a tiny fraction of an inch, and probably a microscopic loss. As I
hinted earlier, if that energy were lost by soaking into the shoe
structure, it would be converted to heat energy. It would be detectable
by an increase in temperature. But when I commuted to work, my office
shoes never seemed to get hot!


Frank, what you are missing is that you don’t always need to waste energy
in order to not put out as much power. I dare you to put out as much power
riding barefoot as you would with shoes. Most riders with most pedals would
find their power dropping, not due to energy wastage, but just because it
would hurt to ride barefoot.


I really wonder. Back when I was a young lad I rode a bicycle
barefooted for much of the summer. Granted that "Summer" in upstate
New Hampshire doesn't last that long but still...
--
Cheers,

John B.

Yeah, we came a long way since 1935....

Lou

On 8/12/2020 9:22 PM, John B. wrote:
On Wed, 12 Aug 2020 21:12:35 -0500, AMuzi wrote:

On 8/12/2020 8:57 PM, John B. wrote:
On Wed, 12 Aug 2020 17:59:20 -0700 (PDT), Frank Krygowski
wrote:

On Wednesday, August 12, 2020 at 8:52:35 PM UTC-4, AMuzi wrote:
On 8/12/2020 6:22 PM, John B. wrote:
On Thu, 13 Aug 2020 06:01:07 +0700, John B.
wrote:

On Wed, 12 Aug 2020 14:54:14 -0700 (PDT), jbeattie
wrote:

On Wednesday, August 12, 2020 at 9:24:50 AM UTC-7, Frank Krygowski wrote:
On 8/11/2020 11:28 PM, jbeattie wrote:
On Tuesday, August 11, 2020 at 6:03:46 PM UTC-7, Frank Krygowski wrote:
On 8/11/2020 6:05 PM, jbeattie wrote:

I certainly pulled up or across the pedal when track racing, and if I pulled out, it could be catastrophic -- and thus double straps and later clipless (some racers used clipless and straps). Foot retention is important when sprinting and climbing out of the saddle. https://www.tandfonline.com/doi/full...0.2020.1769201

It's a shame they didn't test stiff soled cycling shoes with toe clips.
For a long time those were the default choice for avid cyclists. They're
still my choice for long rides.

But I'll point out, that paper (apparently) did not measure efficiency.
The power improvements were huge (9.7???8.7% power gain by adding toe
clips to soft shoes, and 16.6???10.2% gain with rigid shoes and
clipless). On a five percent grade, that corresponds to a very
noticeable increase in speed. If those gains were due to lack of
efficiency of soft soles, those soles must have been soaking up a hell
of a lot of power. That means they should get very hot.

We can discuss this, but I suspect a lot of the gains measured were due
to the "red bikes are faster" effect. Testers were probably
preconditioned to think toe clips help a lot, and REAL cycling shoes and
clipless are what professionals use. That's a recipe for a powerful placebo.

If not that, then what made the power difference? Where would the power
have been previously lost? We should be able to talk about that in detail.

And shoes can make a big difference. I remember going from Detto, Vittoria or Italia (they all blended together) bicycling/bowling shoes of yore with little steel stiffeners and nail on cleats to Duegis with wood soles and bolt-on plastic cleats. https://www.classicsteelbikes.com/wp...-1-600x400.jpg That was huge -- like going from Michelin 50s to Vittoria CGs (I never rode silks). That was probably the single biggest component improvement I ever had.

Again, we should be able to analyze the exact source of the improvement.
The shoes are not a source of power; they are a simple device for
transmitting power from your foot to the pedal.

I don't doubt that some changes allow better biomechanics and thus
better power output. But it's hard for me to see how shoes do that.


A couple of things: (1) your ankle is not a spring, dropping as the sole flexes. Old cycling shoes were really like bowling shoes and not very stiff. (2) Deeper, more secure cleats -- for better or worse. It was not a subtle change for me at all. Others agree: http://stevetilford.com/2016/05/26/cycling-shoes-2/ YMMV.

I'm not surprised that there are people who rhapsodize about shoes. And
I know that certain shoes are more or less comfortable for certain
riders, some shoes have better closure systems, etc. But to return to
_technical_ discussion about power transfer:

Again, the paper you linked could have tested stiff soled shoes with toe
clips. Unfortunately it didn't.

And it's true that "stiff" isn't a binary condition. But aside from
commuting or utility riding, all the cycling shoes I've used (since Bata
Bikers came on the scene) have seemed pretty stiff to me. Not as stiff
as wooden soles, but then, nobody here has identified a mechanism for
power loss through a sole that's a little less stiff.

Thought experiment (since you mention springs): Place a spring with a
high stiffness (say, 100 pounds per inch) on a bike pedal. Place a ten
pound weight on that spring. It will sag 1/10 inch. What's the force on
the pedal?

Repeat with a spring that's less stiff (say, 50 pounds per inch). Place
the same ten pound weight on that spring. It will sag 2/10 inch. What's
the force on that pedal?

The answer is the same in both cases: Pedal force is ten pounds.

It seems pretty simple to me. The power used flexing the sole is not transmitted into the pedal. It is wasted energy. A sloppy shoe-pedal interface is lossy. No? Did you not cinch up your toe-straps before a climb or a sprint?

Rather than trying thought experiments, go and try a pair of stiff shoes in a clipless pedal system. Actually experience the modern world before making grand pronouncement about how nothing makes a difference. And BTW, "pulling up" is not a myth -- as anyone who has pulled out in track sprint can tell you. I almost pulled out of my left shoe last night humping up a hill and had to reach down and cinch up the ratchet -- or if I were you, stop and retie my shoe.

-- Jay Beattie.


If there is a substantial loss of power through "flexing the sole" why
aren't runners wearing hard soled shoes? My guess is that an Olympic
class sprinter is applying at least as much, and possibly more, force
against the ground than a cyclist applies against the pedals. Abebe
Bikila of Ethiopia won an Olympic gold medal in a world-record
2:15:16.2 running barefooted in 1960.

Further to the above, Usain Bolt in breaking the world 100m record
developed a maximum of 2619.5 watts after only 0.89 seconds of the
race.

Not wearing hard soled shoes :-)
--
Cheers,

John B.


Then again Roger Bannister and runners of his era and before
ran in 'running flats', thin very light leather shoes with
leather soles.

And there's been the recent trend of barefoot running.

It may well be that, just like flat or engaged pedals,
humans adapt well to many variants. Crank length seems to be
similar as there aren't objective performance differences
despite rider perception.

Indeed, we're probably the most adaptable animal species ever.

- Frank Krygowski

Perhaps because we aren't "specialized".

A lion can run incredibly fast, about 50 MPH,for a short distance.
Because that is how he gets supper, (actually she gets supper) but
can't climb trees. A Monkey isn't very fast on the flat but scurries
up trees quickly. A human is slower then a lion in a sprint and can't
climb trees as well as the monkey but can do both.

meh.
'We have the Maxim and they have not.'

By "maxim" I assume that you mean Sir Hiram Stevens Maxim's invention
rather than the synonym for "axiom".
--
Cheers,

John B.


It's a quotation and yes it's capitalized.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

On 8/12/2020 9:36 PM, Ralph Barone wrote:
Frank Krygowski wrote:
On Wednesday, August 12, 2020 at 5:54:17 PM UTC-4, jbeattie wrote:
On Wednesday, August 12, 2020 at 9:24:50 AM UTC-7, Frank Krygowski wrote:
I'm not surprised that there are people who rhapsodize about shoes. And
I know that certain shoes are more or less comfortable for certain
riders, some shoes have better closure systems, etc. But to return to
_technical_ discussion about power transfer:

Again, the paper you linked could have tested stiff soled shoes with toe
clips. Unfortunately it didn't.

And it's true that "stiff" isn't a binary condition. But aside from
commuting or utility riding, all the cycling shoes I've used (since Bata
Bikers came on the scene) have seemed pretty stiff to me. Not as stiff
as wooden soles, but then, nobody here has identified a mechanism for
power loss through a sole that's a little less stiff.

Thought experiment (since you mention springs): Place a spring with a
high stiffness (say, 100 pounds per inch) on a bike pedal. Place a ten
pound weight on that spring. It will sag 1/10 inch. What's the force on
the pedal?

Repeat with a spring that's less stiff (say, 50 pounds per inch). Place
the same ten pound weight on that spring. It will sag 2/10 inch. What's
the force on that pedal?

The answer is the same in both cases: Pedal force is ten pounds.

It seems pretty simple to me. The power used flexing the sole is not
transmitted into the pedal. It is wasted energy. A sloppy shoe-pedal
interface is lossy. No? Did you not cinch up your toe-straps before a climb or a sprint?

"It seems pretty simple to me" should be a warning. Imagine Joerg
saying that about a legal issue.

To give you a hint of the complexity, you've conflated "power" and
"energy." ("Force" and "work" are other such quantities. All are
related but not identical; all are used colloquially.)

So, how would an engineer calculate - at least roughly - the energy
lost due to sole flex? It would be the product of the force applied
and the (extra) distance it moves. Seems to me we're talking a distance
of a tiny fraction of an inch, and probably a microscopic loss. As I
hinted earlier, if that energy were lost by soaking into the shoe
structure, it would be converted to heat energy. It would be detectable
by an increase in temperature. But when I commuted to work, my office
shoes never seemed to get hot!


Frank, what you are missing is that you don’t always need to waste energy
in order to not put out as much power. I dare you to put out as much power
riding barefoot as you would with shoes. Most riders with most pedals would
find their power dropping, not due to energy wastage, but just because it
would hurt to ride barefoot.

And BTW, no, I don't cinch up my straps before a climb or sprint.
I did almost no racing, so the sprints were (and still are) fun moments
on a ride with a friend. Climbs? I just climb them. When I did time
trials, I did cinch up and sometimes used racing shoes with cleats.
Did it make a difference? Well, that's the question. I have no data
that proves they did.

Rather than trying thought experiments, go and try a pair of stiff shoes
in a clipless pedal system. Actually experience the modern world before
making grand pronouncement about how nothing makes a difference.

Hey, I actually experienced a brand new bike the other day - a red
one! I could tell that red paint really made it faster! (The color
may have been "Placebo Red.")

That should indicate the problem. It's often hard to tell real benefits
from placebo benefits. That's why sciency guys do measurements and
analyze data.

And BTW, "pulling up" is not a myth -- as anyone who has pulled out in
track sprint can tell you. I almost pulled out of my left shoe last
night humping up a hill and had to reach down and cinch up the ratchet
-- or if I were you, stop and retie my shoe.

Please understand, I'm NOT saying nobody ever pulls up on a pedal. As
I've said, I do on occasion on steep climbs or fast starts - say, to
use a gap in traffic to cross a street. I do that with my slightly
loose toe clip straps. But it's such a tiny portion of my riding it
doesn't matter much.

Apparently some data indicates it may not matter much for anybody.



' because it would hurt to ride barefoot.'

On most pedals, yes.
I could image some enterprising soul with a broad gel faced
platform pedal; it's not impossible.


--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

On Wednesday, August 12, 2020 at 5:44:55 PM UTC-7, John B. wrote:
On Wed, 12 Aug 2020 17:12:03 -0700 (PDT), jbeattie
wrote:

On Wednesday, August 12, 2020 at 4:22:50 PM UTC-7, John B. wrote:
On Thu, 13 Aug 2020 06:01:07 +0700, John B.
wrote:

On Wed, 12 Aug 2020 14:54:14 -0700 (PDT), jbeattie
wrote:

On Wednesday, August 12, 2020 at 9:24:50 AM UTC-7, Frank Krygowski wrote:
On 8/11/2020 11:28 PM, jbeattie wrote:
On Tuesday, August 11, 2020 at 6:03:46 PM UTC-7, Frank Krygowski wrote:
On 8/11/2020 6:05 PM, jbeattie wrote:

I certainly pulled up or across the pedal when track racing, and if I pulled out, it could be catastrophic -- and thus double straps and later clipless (some racers used clipless and straps). Foot retention is important when sprinting and climbing out of the saddle. https://www.tandfonline.com/doi/full...0.2020.1769201

It's a shame they didn't test stiff soled cycling shoes with toe clips.
For a long time those were the default choice for avid cyclists.. They're
still my choice for long rides.

But I'll point out, that paper (apparently) did not measure efficiency.
The power improvements were huge (9.7???8.7% power gain by adding toe
clips to soft shoes, and 16.6???10.2% gain with rigid shoes and
clipless). On a five percent grade, that corresponds to a very
noticeable increase in speed. If those gains were due to lack of
efficiency of soft soles, those soles must have been soaking up a hell
of a lot of power. That means they should get very hot.

We can discuss this, but I suspect a lot of the gains measured were due
to the "red bikes are faster" effect. Testers were probably
preconditioned to think toe clips help a lot, and REAL cycling shoes and
clipless are what professionals use. That's a recipe for a powerful placebo.

If not that, then what made the power difference? Where would the power
have been previously lost? We should be able to talk about that in detail.

And shoes can make a big difference. I remember going from Detto, Vittoria or Italia (they all blended together) bicycling/bowling shoes of yore with little steel stiffeners and nail on cleats to Duegis with wood soles and bolt-on plastic cleats. https://www.classicsteelbikes.com/wp...-1-600x400.jpg That was huge -- like going from Michelin 50s to Vittoria CGs (I never rode silks). That was probably the single biggest component improvement I ever had.

Again, we should be able to analyze the exact source of the improvement.
The shoes are not a source of power; they are a simple device for
transmitting power from your foot to the pedal.

I don't doubt that some changes allow better biomechanics and thus
better power output. But it's hard for me to see how shoes do that.


A couple of things: (1) your ankle is not a spring, dropping as the sole flexes. Old cycling shoes were really like bowling shoes and not very stiff. (2) Deeper, more secure cleats -- for better or worse. It was not a subtle change for me at all. Others agree: http://stevetilford.com/2016/05/26/cycling-shoes-2/ YMMV.

I'm not surprised that there are people who rhapsodize about shoes.. And
I know that certain shoes are more or less comfortable for certain
riders, some shoes have better closure systems, etc. But to return to
_technical_ discussion about power transfer:

Again, the paper you linked could have tested stiff soled shoes with toe
clips. Unfortunately it didn't.

And it's true that "stiff" isn't a binary condition. But aside from
commuting or utility riding, all the cycling shoes I've used (since Bata
Bikers came on the scene) have seemed pretty stiff to me. Not as stiff
as wooden soles, but then, nobody here has identified a mechanism for
power loss through a sole that's a little less stiff.

Thought experiment (since you mention springs): Place a spring with a
high stiffness (say, 100 pounds per inch) on a bike pedal. Place a ten
pound weight on that spring. It will sag 1/10 inch. What's the force on
the pedal?

Repeat with a spring that's less stiff (say, 50 pounds per inch). Place
the same ten pound weight on that spring. It will sag 2/10 inch. What's
the force on that pedal?

The answer is the same in both cases: Pedal force is ten pounds.

It seems pretty simple to me. The power used flexing the sole is not transmitted into the pedal. It is wasted energy. A sloppy shoe-pedal interface is lossy. No? Did you not cinch up your toe-straps before a climb or a sprint?

Rather than trying thought experiments, go and try a pair of stiff shoes in a clipless pedal system. Actually experience the modern world before making grand pronouncement about how nothing makes a difference. And BTW, "pulling up" is not a myth -- as anyone who has pulled out in track sprint can tell you. I almost pulled out of my left shoe last night humping up a hill and had to reach down and cinch up the ratchet -- or if I were you, stop and retie my shoe.

-- Jay Beattie.


If there is a substantial loss of power through "flexing the sole" why
aren't runners wearing hard soled shoes? My guess is that an Olympic
class sprinter is applying at least as much, and possibly more, force
against the ground than a cyclist applies against the pedals. Abebe
Bikila of Ethiopia won an Olympic gold medal in a world-record
2:15:16.2 running barefooted in 1960.

Further to the above, Usain Bolt in breaking the world 100m record
developed a maximum of 2619.5 watts after only 0.89 seconds of the
race.

Not wearing hard soled shoes :-)
--
Cheers,

John B.

Oddly, when we look at professional cyclists, they are all wearing hard-soled shoes. I wonder if there is some difference between running and cycling? Hmmm. Maybe those cyclists have been deceived by marketing!

-- Jay Beattie.

Yes, you are correct, but not because any loss of power due to "sole
flexing".I suggest that it is largely a matter of using very small
angular pedals with sharp edges that would hurt if you stepped on them
bare footed, or even wearing soft soled shoes. But, of course, bicycle
racing people want to ride sleek, slim, slippery, bicycles rather than
having those big, flat, dorky, pedals that you can use bare footed.
See
https://tinyurl.com/y3yl82ev
--

Good luck riding pinned pedals barefooted.

-- Jay Beattie.