Gonchar

Quoted message said:

That said I think it's worth training to ride at a reasonably
high cadence (the usual 90 or so) because it makes the
usual trade of spinning more to delay the onset of fatigue,
and it doesn't come naturally to novices. But anybody
who's moderately trained has probably done this already.

I think what happens is that as you ride more and more your power
increases. I think we observe that cadence goes up but are less likely to
observe that torque was increasing, too. So people observe that "good"
riders spin faster and they think spinning is, in isolation, a good thing
to emulate.

"Robert Chung" <[email hidden]> wrote in
news:[email hidden]:

Quoted message said:

Quoted message said:

That said I think it's worth training to ride at a reasonably
high cadence (the usual 90 or so) because it makes the
usual trade of spinning more to delay the onset of fatigue,
and it doesn't come naturally to novices. But anybody
who's moderately trained has probably done this already.

I think what happens is that as you ride more and more your power
increases. I think we observe that cadence goes up but are less likely
to observe that torque was increasing, too. So people observe that
"good" riders spin faster and they think spinning is, in isolation, a
good thing to emulate.

What about riders who use a high cadence, but it's so high they are
bouncing around so much they look like a 300-lb guy on a Softride? When
you are going for a high cadence, should you start out by balancing a
wine glass or beer can on your helmet and only pedal as fast as you can
without the glass or can falling off? Or will wearing a wine glass on
your helmet just make you look like some RAGBRAI-type rider? What should
I use so people will know I am working on spinning a high cadence
smoothly and not just riding around with a wine glass on my helmet as
some sort of weird organized ride thing? Or is the helmet the thing that
separates "training" from "stupid" and you should use one of those little
cycling caps and balance the wine glass on the cap on your head?

--
Bill Asher

Robert Chung said:

Hansen, et al. 2002. "Crank inertial load affects freely chosen pedal rate
during cycling." Journal of Biomechanics 35: 277-285.

Abstract

Cyclists seek to maximize performance during competition, and gross
efficiency is an important factor affecting performance. Gross
efficiency is itself affected by pedal rate. Thus, it is important to
understand factors that affect freely chosen pedal rate. Crank
inertial load varies greatly during road cycling based on the selected
gear ratio. Nevertheless, the possible influence of crank inertial
load on freely chosen pedal rate and gross efficiency has never been
investigated. This study tested the hypotheses that during cycling
with sub-maximal work rates, a considerable increase in crank inertial
load would cause (1) freely chosen pedal rate to increase, and as a
consequence, (2) gross efficiency to decrease. Furthermore, that it
would cause (3) peak crank torque to increase if a constant pedal rate
was maintained. Subjects cycled on a treadmill at 150 and 250 W, with
low and high crank inertial load, and with preset and freely chosen
pedal rate. Freely chosen pedal rate was higher at high compared with
low crank inertial load. Notably, the change in crank inertial load
affected the freely chosen pedal rate as much as did the 100 W
increase in work rate. Along with freely chosen pedal rate being
higher, gross efficiency at 250 W was lower during cycling with high
compared with low crank inertial load. Peak crank torque was higher
during cycling at 90 rpm with high compared with low crank inertial
load. Possibly, the subjects increased the pedal rate to compensate
for the higher peak crank torque accompanying cycling with high
compared with low crank inertial load.

ID
rotational inertia of each wheel about its axis of rotation 0.1786
(kg m2)
IF
combined rotational inertia of the pedals, crank arms, and chain
wheels about the crank axis 0.0355 (kg m2)
IG
rotational inertia of the freewheel 0.0003 (kg m2)
mB
mass of the bicycle frame1 6.416 (kg)2 (see 2)
mC
mass of the subject (variable, see text) (see 2)
mD
mass of each wheel 1.973 (kg) (see 2)
mF
combined mass of the chain wheels, crank arms, and pedals 1.660
(kg) (see 2)
mG
mass of the freewheel 0.317 (kg) (see 2)
mW
mass on the weight magazine (incl. the weight magazine) (variable,
see text) (see 2)
RD
radius of each wheel 0.3429 (m) (see 2)
RF
number of teeth in the chain wheel (variable, see text) (see 2)
RG
number of teeth in the freewheel (variable, see text) (see 2)

(1) In this context the bicycle frame represents the whole bicycle
minus the wheels, crank arms, and pedals.
(2) Determined in this study.

--
E. Dronkert

William Asher said:

When
you are going for a high cadence, should you start out by balancing a
wine glass or beer can on your helmet and only pedal as fast as you can
without the glass or can falling off?

There is no reason to put a glass of wine at risk just to prove some
silly training theory. Unless the wine is called 'Supplesse'. Then you
could be riding with Supplesse. Which calls for you to dance on the
pedals a lot.

Curtis L. Russell
Odenton, MD (USA)
Just someone on two wheels...

Curtis L. Russell said:

There is no reason to put a glass of wine at risk just to prove some
silly training theory. Unless the wine is called 'Supplesse'. Then you
could be riding with Supplesse. Which calls for you to dance on the
pedals a lot.

Maybe its OK if you use cheap wine or sherry.

Robert Chung said:

Bret said:

Robert Chung said:

Bret wrote:

> Do you not agree that for a given condition (flat road, no wind, time
> trialing) every rider has a maximum power that they can generate at a
> given cadence and that when plotted would be zero at the extremes with
> a peak at some point in between

Sorta, but I think finding that maximum isn't quite as easy as you
appear to think it is.

Why is that? Do you think that the slope of the Power curve is too low
to detect the peak?

No, not exactly, it's because power is a rate over time, and "maximum"
power is going to be affected by the length of time over which it is
measured even for a particular cadence. Max one-second power at a given
cadence is going to be different than max 30-second power (or 1 minute, or
5 minute, or 1 hour). So, explain the experiment that you'd do to find,
say, max 5 second power at 90 rpm. How do you keep your cadence constant
at 90 rpm for that length of time? How do you know that was your best
effort? Or perhaps you meant max power over one comple crank revolution,
at many different rpms (e.g., max power for 1 second at 60 rpm, max power
for .67 seconds at 90 rpm, max power for .5 seconds at 120 rpm). Getting
this latter thing would be simpler but I'm not sure what practical use
there is in knowing max power over 1 crank revolution at a given cadence.
What do you think it's useful for?

I'm talking about maximum sustainable power (I did mention time
trialing) at an interval sufficiently long for the body's reaction to
stabilize. For an experiment, I'd use a Velodyne in ergometer mode and
gradually increase power while maintaining a steady cadence until heart
rate reached what I consider from experience to be my maximum
sustainable level. Then I would repeat for other cadences. Then I would
repeat the test in a different order to control for fatigue and heat
drift. What results would you expect? I might really do this some time.

Quoted message said:

Quoted message said:

Quoted message said:

> You see no value in finding that peak?

Not really, except for curiosity's sake. I don't think it has a very
important prescriptive role in terms of training. See
http://home.earthlink.net/~acoggan/setraining , especially figure 2.

You are focused on cadence as a training tool and Andy's main point in
the article is that low cadence workouts are ineffective as strength
training. But I'm not talking about that or any other training method.
I'm talking about finding the cadence for maximum power transfer and
using it when maximum power is needed.

Actually, I'm not focused on cadence solely as a training tool. I don't
think it has a prescriptive role in training, yes; but I also don't think
it has a prescriptive role in racing.

Quoted message said:

Regarding figure 2, the plot of max AEPF vs. CPV (solid black line)
indicates that peak power is at 120 RPM (stated in the linked article).
I'm a little unclear how that line was plotted.

From standing start data. But one of the things to notice was that the
solid line was pretty linear over a wide range of cadences. If you have a
linear relationship between pedal speed and pedal force, their product is
maximized at half of max speed (and half of max force). So if you knew max
cadence was around n, you'd know max power is attained at around n/2. But
you weren't asking about the cadence that maximizes power, you were asking
about the max power at each level of cadence. So I was pointing at figure
2 to show that the max 1 revolution power at different cadences is way
above the power you use in racing situations (that's why the line is above
the color blobs).

I was speaking of maximum sustainable power at each cadence. Is there a
relationship between that and max 1 revolution power at the same
cadence? Or are you just showing me how inprecise my language was?

Quoted message said:

Though I sort of like your implication for an entirely new category of
Master Fatty excuses: "I had the wrong cadence when he attacked."

Nah. More knowedge would mean fewer excuses.

Bret

Bret said:

I'm talking about maximum sustainable power (I did mention time
trialing) at an interval sufficiently long for the body's reaction to
stabilize.

Ah. That's different.

For an experiment, I'd use a Velodyne in ergometer mode and

Quoted message said:

gradually increase power while maintaining a steady cadence until heart
rate reached what I consider from experience to be my maximum
sustainable level. Then I would repeat for other cadences. Then I would
repeat the test in a different order to control for fatigue and heat
drift. What results would you expect? I might really do this some time.

I'd expect that you'd find that as long as you're well away from the
linear boundary in Andy's fig. 2, muscular contraction speed in and of
itself isn't going to be the limiting factor. In that case, I think you'll
find that you can produce functional threshold power at many different
combos of cadence and torque.

Robert Chung said:

I'd expect that you'd find that as long as you're well away from the
linear boundary in Andy's fig. 2, muscular contraction speed in and of
itself isn't going to be the limiting factor. In that case, I think you'll
find that you can produce functional threshold power at many different
combos of cadence and torque.

I've been stair stepping once or twice a week on the same machine for
about 10-12 years. It reads my power output in watts so I'm quite
familiar with what I am capable of. The steps are lever arms that hold
me off the ground. The higher the intensity I program into the machine,
the faster the steps fall (they spring back automatically) and the
harder I have to work to stay off the ground. I can do this by stepping
with smaller but faster steps, or bigger and slower. Regardless, I can
produce only the same threshold power. There's only so much in the
engine room.

Wayne

Wayne Pein said:

Robert Chung said:

I'd expect that you'd find that as long as you're well away from the
linear boundary in Andy's fig. 2, muscular contraction speed in and of
itself isn't going to be the limiting factor. In that case, I think you'll
find that you can produce functional threshold power at many different
combos of cadence and torque.

I've been stair stepping once or twice a week on the same machine for
about 10-12 years. It reads my power output in watts so I'm quite
familiar with what I am capable of. The steps are lever arms that hold
me off the ground. The higher the intensity I program into the machine,
the faster the steps fall (they spring back automatically) and the
harder I have to work to stay off the ground. I can do this by stepping
with smaller but faster steps, or bigger and slower. Regardless, I can
produce only the same threshold power. There's only so much in the
engine room.

It seems pretty clear that the limiting factor is cardio-fitness for
semi-sustainable efforts. The big question for me is what about long
term sustainability? Endurance? What leaves you the most fresh after
4-6 hours (or more) in the saddle?

Joseph

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

Quoted message said:

What leaves you the most fresh after
4-6 hours (or more) in the saddle?

Alcohol, then baby wipes.

Carl Sundquist said:

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

Quoted message said:

What leaves you the most fresh after
4-6 hours (or more) in the saddle?

Alcohol, then baby wipes.

Inside, outside, respectively.

Ron

joseph.santaniello said:

Quoted message said:

What leaves you the most fresh after
4-6 hours (or more) in the saddle?

Carl Sundquist said:

Alcohol, then baby wipes.

Is baby wipes some new kind of LiveDrunk(tm) cocktail ?

Ewoud, "crank inertial load" seems like one of those terms pulled out of the
air. Does it make any sense to you? I mean, what are they referring to
exactly?

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

Quoted message said:

Robert Chung said:

Hansen, et al. 2002. "Crank inertial load affects freely chosen pedal rate
during cycling." Journal of Biomechanics 35: 277-285.

Abstract

Cyclists seek to maximize performance during competition, and gross
efficiency is an important factor affecting performance. Gross
efficiency is itself affected by pedal rate. Thus, it is important to
understand factors that affect freely chosen pedal rate. Crank
inertial load varies greatly during road cycling based on the selected
gear ratio. Nevertheless, the possible influence of crank inertial
load on freely chosen pedal rate and gross efficiency has never been
investigated. This study tested the hypotheses that during cycling
with sub-maximal work rates, a considerable increase in crank inertial
load would cause (1) freely chosen pedal rate to increase, and as a
consequence, (2) gross efficiency to decrease. Furthermore, that it
would cause (3) peak crank torque to increase if a constant pedal rate
was maintained. Subjects cycled on a treadmill at 150 and 250 W, with
low and high crank inertial load, and with preset and freely chosen
pedal rate. Freely chosen pedal rate was higher at high compared with
low crank inertial load. Notably, the change in crank inertial load
affected the freely chosen pedal rate as much as did the 100 W
increase in work rate. Along with freely chosen pedal rate being
higher, gross efficiency at 250 W was lower during cycling with high
compared with low crank inertial load. Peak crank torque was higher
during cycling at 90 rpm with high compared with low crank inertial
load. Possibly, the subjects increased the pedal rate to compensate
for the higher peak crank torque accompanying cycling with high
compared with low crank inertial load.

ID
rotational inertia of each wheel about its axis of rotation 0.1786
(kg m2)
IF
combined rotational inertia of the pedals, crank arms, and chain
wheels about the crank axis 0.0355 (kg m2)
IG
rotational inertia of the freewheel 0.0003 (kg m2)
mB
mass of the bicycle frame1 6.416 (kg)2 (see 2)
mC
mass of the subject (variable, see text) (see 2)
mD
mass of each wheel 1.973 (kg) (see 2)
mF
combined mass of the chain wheels, crank arms, and pedals 1.660
(kg) (see 2)
mG
mass of the freewheel 0.317 (kg) (see 2)
mW
mass on the weight magazine (incl. the weight magazine) (variable,
see text) (see 2)
RD
radius of each wheel 0.3429 (m) (see 2)
RF
number of teeth in the chain wheel (variable, see text) (see 2)
RG
number of teeth in the freewheel (variable, see text) (see 2)

(1) In this context the bicycle frame represents the whole bicycle
minus the wheels, crank arms, and pedals.
(2) Determined in this study.

--
E. Dronkert

Tom Kunich said:

Ewoud, "crank inertial load" seems like one of those terms pulled out of the
air. Does it make any sense to you?

It's just weight on the pedal (including weight times arm of all
components of the drivetrain, afaict).

--
E. Dronkert

Quoted message said:

It seems pretty clear that the limiting factor is cardio-fitness for
semi-sustainable efforts. The big question for me is what about long
term sustainability? Endurance? What leaves you the most fresh after
4-6 hours (or more) in the saddle?

Joseph

I think if one wants to go as fast as possible for that long or longer,
optimal cadence can be quite variable. For one, it would be hard to
test, n being small. You could ride a stationary bike at different
cadences with the same watt output to check out how you feel at the end.
Also, it would be very mentally and physically taxing to hold a steady
cadence. Variability gives the mind and body a break.

As another anecdotal example, I've also used an upper body ergometer
twice a week for years. It's basically a bicycle for the upper body. I
mix up the routines I do. Two, however, are similar. For 10 minutes I
hold about 400 watts turning about 60 rpm, or I hold about 160 watts
turning about 105 rpm. Surprisingly, while the 400 watt effort IS more
taxing on me, the 160 watt effort is almost as much perceived exertion,
and certainly not less than half as tough. The reason is that
maintaining that high of a cadence is really difficult.

Wayne

Ewoud Dronkert said:

Tom Kunich said:

Ewoud, "crank inertial load" seems like one of those terms pulled out of the
air. Does it make any sense to you?

It's just weight on the pedal (including weight times arm of all
components of the drivetrain, afaict).

This idea of crank intertia is quite intriguing. I have previoulsy only
ever thought about force, crank length and pedal speed. As I understand
it crank inertia is the "stickiness" of a given cadence. If you think
about riding up a steep hill, as soon as you back off, everything slows
quickly and it is hard to keep a smooth pedaling style. This is low
crank intertia. At high speed on flats, easing off does not have as
drastic an effect. Flywheel of sorts, but it also includes the inertia
of the rider and the forces of resistance.

I wonder if my high-ish weight and super low cadence have any effect
(and what it is) on my perception of crank inertial while riding.

Joseph