Clipless pedals no more efficient than flat?

Frank Krygowski wrote:
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


Of course you didn’t, and probably for the same reason as the example I put
out. Even though there would be no greater energy (or power, take your
pick) losses riding barefoot, the localized areas of increased pressure on
the sole of your foot would result in a tendency to apply less force
because it would be uncomfortable to apply more. If you’ve ever run
barefoot and landed on a pebble, you notice it. So stiff soles shoes can
allow greater power transfer simply by making it more comfortable to do so
for sustained periods.

IJohn 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 donÂ’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.



I’m sure we’ve all rode barefoot or with minimal footwear at one time or
another. The question is “Were you at the head of the peloton while doing
so?�

On 8/13/2020 10:49 AM, Ralph Barone wrote:
Frank Krygowski wrote:
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


Of course you didn’t, and probably for the same reason as the example I put
out. Even though there would be no greater energy (or power, take your
pick) losses riding barefoot, the localized areas of increased pressure on
the sole of your foot would result in a tendency to apply less force
because it would be uncomfortable to apply more. If you’ve ever run
barefoot and landed on a pebble, you notice it. So stiff soles shoes can
allow greater power transfer simply by making it more comfortable to do so
for sustained periods.

OK, that's more understandable.

I don't doubt that if a person used to have pain, hot foot, numb toes
etc. from older style equipment, that person could produce more power
with comfortable shoes.

But I and several of my friends use "touring" cycling shoes with toe
clips. I've never had any discomfort, and I've never heard those friends
complain. I don't believe we'd see any power increase by changing to
special clipless shoes. In fact, I suspect the formerly uncomfortable
guy I described above could do just as well if he found a _comfortable_
pair of shoes like I use.

Incidentally, we know a couple that are extremely avid tourists and
utility cyclists - the most dedicated in our area. They routinely spend
months at a time touring Europe or the U.S., camping all the way. They
love SPD sandals. That makes me wonder about the "efficiency" and
"pulling up" on a sandal that's firmly clipped to the pedal, but
compared to a shoe, only loosely attached to one's foot.

Of course, I think it makes negligible difference. But do clipless shoe
fans disparage clipless sandals?

--
- Frank Krygowski

On 2020-08-12 14:15, Tom Kunich wrote:
On Tuesday, August 11, 2020 at 11:26:40 AM UTC-7, Joerg wrote:
On 2020-08-10 18:49, bob prohaska wrote:
I found this not-entirely-ancient video,
https://www.youtube.com/watch?v=KUEaN9FKGLE which posits that
there's no efficiency gain using clipless (or traditional
toe-clips) in terms of rider performance.

That's a considerable surprise. It certainly _felt_ more
efficient to use clips/straps, and then Shimano SPDs, compared to
flat pedals.

Am I a victim of self-deception? Or worse yet, marketing?

There is something to it. When applying force also in the
pulling-up phase you are using muscles in your legs that you
wouldn't be able to use with regular flat pedals.

However, my limit aren't the leg muscles, I simply run out of
breath on a long steep climb or when "flooring it" on a bike path
that has no speed limit. Long story short I used to ride with loop
pedals which offer the same "pulling up" advantage as SPD and
similar. When I switched to MTB flat pedals I found no difference
in my performance when it comes to average speed.

As for slipping off the pedals I never found that to be an issue. I
have to use them because I ride with sandals most of the year. So I
did something that makes purists cringe, I mounted MTB pedals on my
road bike. It's the lower cost plastic kind because those allowed
me to cut and then round the spikes to about half their length.
This reduces the wear on bottoms of shoes and also the gashes in
case I crash hard.

-- Regards, Joerg

http://www.analogconsultants.com/
Yes, but it all comes from your lungs and circulatory system which is
the limiting factor.


That is exactly my point, that is why my muscles aren't the limiting
factor. Before they redline I am running out of breath.


... A circular pedals stroke allows some of your
muscles to rest while others are working. This is only a SMALL but
important effect for professional racers.


Yeah, but even if I wasn't limited by lung capacity I do not need to win
a race. Cycling is supposed to be fun, at least most of the time.

--
Regards, Joerg

http://www.analogconsultants.com/

Frank Krygowski wrote:
On 8/13/2020 10:49 AM, Ralph Barone wrote:
Frank Krygowski wrote:
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


Of course you didn’t, and probably for the same reason as the example I put
out. Even though there would be no greater energy (or power, take your
pick) losses riding barefoot, the localized areas of increased pressure on
the sole of your foot would result in a tendency to apply less force
because it would be uncomfortable to apply more. If you’ve ever run
barefoot and landed on a pebble, you notice it. So stiff soles shoes can
allow greater power transfer simply by making it more comfortable to do so
for sustained periods.

OK, that's more understandable.

I don't doubt that if a person used to have pain, hot foot, numb toes
etc. from older style equipment, that person could produce more power
with comfortable shoes.

But I and several of my friends use "touring" cycling shoes with toe
clips. I've never had any discomfort, and I've never heard those friends
complain. I don't believe we'd see any power increase by changing to
special clipless shoes. In fact, I suspect the formerly uncomfortable
guy I described above could do just as well if he found a _comfortable_
pair of shoes like I use.

Incidentally, we know a couple that are extremely avid tourists and
utility cyclists - the most dedicated in our area. They routinely spend
months at a time touring Europe or the U.S., camping all the way. They
love SPD sandals. That makes me wonder about the "efficiency" and
"pulling up" on a sandal that's firmly clipped to the pedal, but
compared to a shoe, only loosely attached to one's foot.

Of course, I think it makes negligible difference. But do clipless shoe
fans disparage clipless sandals?


Hey, I think we may be slowly converging on a statement we can both agree
on. Your major cycling mode is touring/commuting (pretty much the same as
me), and for that, I don’t think that changing shoes is going to magically
make an extra 14 W appear at the crank. However, I think the study that was
referenced probably had to do with racing, and under those conditions, a
better foot-pedal interface can allow the rider to put out a few more Watts
because you don’t have to use those Watts to ensure that your foot stays on
the pedal and the stiff sole ensures that the force is applied evenly
across the bottom of the foot.

On Monday, 10 August 2020 21:49:48 UTC-4, bob prohaska wrote:
I found this not-entirely-ancient video,
https://www.youtube.com/watch?v=KUEaN9FKGLE
which posits that there's no efficiency gain
using clipless (or traditional toe-clips) in
terms of rider performance.

That's a considerable surprise. It certainly
_felt_ more efficient to use clips/straps,
and then Shimano SPDs, compared to flat pedals.

Am I a victim of self-deception? Or worse yet,
marketing?

Thanks for reading,

bob prohaska

I find that a stiff sole shoe and clipless or toe-clip and straps pedals make a huge difference after many hours of pedaling my bicycle. I know that on some longer hills that I pull up hard on the pedals and I'm glad that I'm able to do so as it beats getting off the bike and pushing the loaded bike up the hill.

Others may prefer to walk, I like to ride whenever possible especially on dirt roads with a bit of loose surface where pushing the loaded bike often results in the bike almost stationary but me moving backwards down the hill.

Cheers

On 8/13/2020 12:09 PM, Ralph Barone wrote:
Frank Krygowski wrote:
On 8/13/2020 10:49 AM, Ralph Barone wrote:
Frank Krygowski wrote:
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


Of course you didn’t, and probably for the same reason as the example I put
out. Even though there would be no greater energy (or power, take your
pick) losses riding barefoot, the localized areas of increased pressure on
the sole of your foot would result in a tendency to apply less force
because it would be uncomfortable to apply more. If you’ve ever run
barefoot and landed on a pebble, you notice it. So stiff soles shoes can
allow greater power transfer simply by making it more comfortable to do so
for sustained periods.

OK, that's more understandable.

I don't doubt that if a person used to have pain, hot foot, numb toes
etc. from older style equipment, that person could produce more power
with comfortable shoes.

But I and several of my friends use "touring" cycling shoes with toe
clips. I've never had any discomfort, and I've never heard those friends
complain. I don't believe we'd see any power increase by changing to
special clipless shoes. In fact, I suspect the formerly uncomfortable
guy I described above could do just as well if he found a _comfortable_
pair of shoes like I use.

Incidentally, we know a couple that are extremely avid tourists and
utility cyclists - the most dedicated in our area. They routinely spend
months at a time touring Europe or the U.S., camping all the way. They
love SPD sandals. That makes me wonder about the "efficiency" and
"pulling up" on a sandal that's firmly clipped to the pedal, but
compared to a shoe, only loosely attached to one's foot.

Of course, I think it makes negligible difference. But do clipless shoe
fans disparage clipless sandals?


Hey, I think we may be slowly converging on a statement we can both agree
on.

Is that allowed here??


--
- Frank Krygowski

On Thursday, August 13, 2020 at 9:09:25 AM UTC-7, Ralph Barone wrote:
Frank Krygowski wrote:
On 8/13/2020 10:49 AM, Ralph Barone wrote:
Frank Krygowski wrote:
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


Of course you didn’t, and probably for the same reason as the example I put
out. Even though there would be no greater energy (or power, take your
pick) losses riding barefoot, the localized areas of increased pressure on
the sole of your foot would result in a tendency to apply less force
because it would be uncomfortable to apply more. If you’ve ever run
barefoot and landed on a pebble, you notice it. So stiff soles shoes can
allow greater power transfer simply by making it more comfortable to do so
for sustained periods.

OK, that's more understandable.

I don't doubt that if a person used to have pain, hot foot, numb toes
etc. from older style equipment, that person could produce more power
with comfortable shoes.

But I and several of my friends use "touring" cycling shoes with toe
clips. I've never had any discomfort, and I've never heard those friends
complain. I don't believe we'd see any power increase by changing to
special clipless shoes. In fact, I suspect the formerly uncomfortable
guy I described above could do just as well if he found a _comfortable_
pair of shoes like I use.

Incidentally, we know a couple that are extremely avid tourists and
utility cyclists - the most dedicated in our area. They routinely spend
months at a time touring Europe or the U.S., camping all the way. They
love SPD sandals. That makes me wonder about the "efficiency" and
"pulling up" on a sandal that's firmly clipped to the pedal, but
compared to a shoe, only loosely attached to one's foot.

Of course, I think it makes negligible difference. But do clipless shoe
fans disparage clipless sandals?

Hey, I think we may be slowly converging on a statement we can both agree
on. Your major cycling mode is touring/commuting (pretty much the same as
me), and for that, I don’t think that changing shoes is going to magically
make an extra 14 W appear at the crank. However, I think the study that was
referenced probably had to do with racing, and under those conditions, a
better foot-pedal interface can allow the rider to put out a few more Watts
because you don’t have to use those Watts to ensure that your foot stays on
the pedal and the stiff sole ensures that the force is applied evenly
across the bottom of the foot.
I thought your point was pretty clear. Why do you suppose that people want to subvert the subject and argue about something that wasn't meant?

Lou Holtman wrote:
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


Some folks haven’t noticed though.

On Thu, 13 Aug 2020 05:13:09 -0700 (PDT), Lou Holtman
wrote:

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

1944 actually :-)
--
Cheers,

John B.