Beware of PowerCranks

[Bill]

Tom Kunich wrote:
> As Robert pointed out, I've been using the incorrect names - my
> ex-brother-in-law was born WITH a coronary artery but without the AORTA
> believe it not.
>
> "Tom Kunich" <cyclintom@yahoo. com> wrote in message
> news:[email protected]...
>> "Bill" <[email protected]> wrote in message
>> news:[email protected]...
>>> Michael Press wrote:
>>>> In article <[email protected]>
>>>> ,
>>>> "Tom Kunich" <cyclintom@yahoo. com> wrote:
>>>>> I have an ex-brother in law who was the longest surviving person
>>>>> without a main coronary artery.
>>> Huh? How did he live at all without a main coronary artery?
>>> This sounds impossible.
>> "Sounds" is not "is". This is a known birth defect and occurs often enough
>> that they were familiar with the condition when they shoved a catheter
>> through the deadend of the coronary artery. In his case the minor arteries
>> and a hole between the chambers of his heart sufficed to keep him alive
>> though he was a blue baby. His whole life each succeeding doctor told him
>> that he only had a couple of months to a year to live.
>>
>> He is now about 55 and back in the mid-90's they replaced 25% of his heart
>> with one that had a coronary artery on it and then later they had to go in
>> and replace the valve with a mechanical valve. And then that valve failed
>> and they had to replace it again.
>>
>> He stood for the bar and passed so he knew what his rights were and
>> managed to maintain health insurance his whole life with Kaiser. Believe
>> me they grumbled a whole lot but they have kept him alive and he has two
>> daughters and worked most of his life.
>>
>> After he had his heart repaired and his VO2 went from 70% to 99% he acted
>> like a drunk for a couple of years until he adjusted to not having oxygen
>> his whole life.
>>
>>
>
>
Kind of amazing story there. If he lived all that time and there are
more like him that really does make for a survival tale.
Cheers,
Bill Baka

 

[Bill]

Tom Kunich wrote:
> "Ewoud Dronkert" <[email protected]> wrote in message
> news:[email protected]...
>> On Wed, 06 Jun 2007 02:34:37 GMT, Bill wrote:
>>> Like maybe those silly oval crank rings about 15-20 years back?
>> They're back and called Q-Rings.
>
> And the oval rings stuff started WAY back in the 20's I think. Every couple
> of decades someone reinvents things.
>
> But that is the way of the world. When researching an invention of my uncle
> back in the 60's, I discovered the identical invention every 20 years since
> the patent office opened.
>
>
Weren't they called Ergo rings or something like that? I had a set on my
Schwinn Super Sport and they just felt strange to ride so I tossed them
and use regular rings now.
Bill Baka

 

[Davey Crockett]

* Bill <[email protected]> a écrit
> Tom Kunich wrote:
>> "Ewoud Dronkert" <[email protected]> wrote in message
>> news:[email protected]...
>>> On Wed, 06 Jun 2007 02:34:37 GMT, Bill wrote:
>>>> Like maybe those silly oval crank rings about 15-20 years back?
>>> They're back and called Q-Rings.
>>
>> And the oval rings stuff started WAY back in the 20's I think. Every
>> couple of decades someone reinvents things.
>>
>> But that is the way of the world. When researching an invention of
>> my uncle back in the 60's, I discovered the identical invention
>> every 20 years since the patent office opened.
>>
>>
> Weren't they called Ergo rings or something like that? I had a set on
> my Schwinn Super Sport and they just felt strange to ride so I tossed
> them and use regular rings now.
> Bill Baka

Bio-Pace was the last incarnation of the non-round chainring I think

JF-Bernard used to have bikes putatively equipped with them, but
closer inspection of his bike revealed that the only thing bio-pace
was the decal since Shimano sponsored the Look squad in those days

His rings were round

--
Le vent à Dos
Davey Crockett [No 4Q to reply]

 

[Andy Coggan]

On Jun 2, 9:39 pm, "Phil Holman" <piholmanc@yourservice> wrote:

> Frank Day. His last posts here were after a scientific study showed a
> statistically significant 1.5% gross efficiency improvement. The experts
> here still wouldn't buy it.

It wasn't a case of "not buying it", but how to interpret it.

Andy Coggan

 

[Andy Coggan]

On Jun 3, 12:58 pm, "Phil Holman" <piholmanc@yourservice> wrote:

> I just checked their website and found another study of trained cyclists
> that showed a 15.6% increase in VO2max and an 11.6% icrease in max
> power.

Yeah, training will do that for you (or at least it should).

Andy Coggan (whose sustainable power is up 11% in the last 10 wk)

 

[Andy Coggan]

On Jun 3, 3:02 pm, "Phil Holman" <piholmanc@yourservice> wrote:

> What does it take to get an appropriate and properly
> designed test?

Somebody who knows what they're doing? ;-)

Andy Coggan

 

[Andy Coggan]

On Jun 3, 3:16 pm, Tim McNamara <[email protected]> wrote:

> My understanding- which may not be correct- is that VO2 max is
> biologically determined and that training does not significantly change
> this.

Your understanding is incorrect: VO2max (in mL/min/kg) increases by
15-25% with just moderate training, and by up to 60% with more
prolonged/extensive training. Even elite athletes who have been
training for many years routinely experience swings in VO2max of up to
10% (sometimes more) between the peak of in-season fitness and the
nadir of off-season slothdom.

Andy Coggan

 

[Andy Coggan]

On Jun 5, 11:04 pm, "Phil Holman" <piholmanc@yourservice> wrote:
> <[email protected]> wrote in message

> > In recent times, steam RR locomotives, although not rated in Horse
> > Power (but rather "tractive effort", the pull at which the wheels
> > would spin) had a conversion chart to HP based on grate area in the
> > fire box which governs how much heat can be transferred to steam in
> > the boiler. Grate area is closely similar to lung displacement for
> > physically fit racers. That is what limits climbing or TT ability,
> > not ankling, pedaling style or other external means.
>
> You continue to repeat this misconception. Lung displacement or lung
> capacity is not the limiting factor in climbing or TTing or cycling in
> general. If you understood the cause and effect elements you would
> understand that extreme "out of breath" is caused by excess CO2 in the
> blood stream as a result of lactic buffering.

Great! Now we have one engineer feeding misconceptions about how
physiology functions to another engineer...

Fact: CO2 plays only a very limited role in regulating ventilation
during exercise.

> That is, the limits of
> aerobic capacity were reached upstream (cardiac output, blood muscle
> interface limitations etc) and no further limitations are imposed by the
> lungs. It wouldn't matter if you doubled lung capacity, blood lactate
> concentrations wouldn't change and this is the culminating event in
> limiting aerobic performance. Heavy breathing is an effect not a cause.

In fact, mild-to-moderate arterial desaturation tends to occur during
maximal exercise in a significant portion of the population (at least
discounting young, healthy, untrained men!), indicating that, at least
to some extent, aerobic capacity (i.e., VO2max) is limited, in part,
by pulmonary function.

Andy Coggan

 

[Bill]

Andy Coggan wrote:
> On Jun 5, 11:04 pm, "Phil Holman" <piholmanc@yourservice> wrote:
>> <[email protected]> wrote in message
>
>>> In recent times, steam RR locomotives, although not rated in Horse
>>> Power (but rather "tractive effort", the pull at which the wheels
>>> would spin) had a conversion chart to HP based on grate area in the
>>> fire box which governs how much heat can be transferred to steam in
>>> the boiler. Grate area is closely similar to lung displacement for
>>> physically fit racers. That is what limits climbing or TT ability,
>>> not ankling, pedaling style or other external means.
>> You continue to repeat this misconception. Lung displacement or lung
>> capacity is not the limiting factor in climbing or TTing or cycling in
>> general. If you understood the cause and effect elements you would
>> understand that extreme "out of breath" is caused by excess CO2 in the
>> blood stream as a result of lactic buffering.
>
> Great! Now we have one engineer feeding misconceptions about how
> physiology functions to another engineer...
>
> Fact: CO2 plays only a very limited role in regulating ventilation
> during exercise.

Another fact: The reason you can't hold your breath for more than about
2 minutes, even while sitting, is the CO2 buildup in the airways causing
a forced breathing reflex.
Even someone who is not working out can exercise the lungs, as I used to
do during long car commutes. Inhale to the absolute maximum and hold for
as long as possible. I gained some lung volume from doing that on long
boring stretches of road. Sounds lame, but it worked.
>
>> That is, the limits of
>> aerobic capacity were reached upstream (cardiac output, blood muscle
>> interface limitations etc) and no further limitations are imposed by the
>> lungs. It wouldn't matter if you doubled lung capacity, blood lactate
>> concentrations wouldn't change and this is the culminating event in
>> limiting aerobic performance. Heavy breathing is an effect not a cause.
>
> In fact, mild-to-moderate arterial desaturation tends to occur during
> maximal exercise in a significant portion of the population (at least
> discounting young, healthy, untrained men!), indicating that, at least
> to some extent, aerobic capacity (i.e., VO2max) is limited, in part,
> by pulmonary function.
>
> Andy Coggan
>
I have to wonder whether it is my legs anaerobic capacity that is being
depleted in my daily 'suicide' runs, as in sprint until no longer able
to run at all. Only after dropping to a walk does my heart and lungs get
the idea they should be doing more. My breathing and pulse don't seem to
peak until about 30 seconds after the run of about the same time.
Is that a normal thing or am I just breaking the rules of exercise???
Cycling I can't even get to that state of totally out of breath and high
pulse rate. Maybe an imbalance between leg fitness and cardio fitness??
Bill Baka

 

[Tim McNamara]

In article <[email protected]>,
Andy Coggan <[email protected]> wrote:

> On Jun 3, 3:16 pm, Tim McNamara <[email protected]> wrote:
>
> > My understanding- which may not be correct- is that VO2 max is
> > biologically determined and that training does not significantly
> > change this.
>
> Your understanding is incorrect: VO2max (in mL/min/kg) increases by
> 15-25% with just moderate training, and by up to 60% with more
> prolonged/extensive training. Even elite athletes who have been
> training for many years routinely experience swings in VO2max of up
> to 10% (sometimes more) between the peak of in-season fitness and the
> nadir of off-season slothdom.

Thanks. I wish I still was in touch with that exercise physiologist to
update him...

 

[Andy Coggan]

On Jun 3, 9:01 pm, "Phil Holman" <piholmanc@yourservice> wrote:
> "A Muzi" <[email protected]> wrote in message
>
> news:[email protected]...
>
>
>
>
>
> >>>>> Ride Faster <[email protected]> wrote:
> >>>>>> I had the same experience with PowerCranks. This product is
> >>>>>> garbage.
>
> >>>> "[email protected]" <[email protected]> wrote:
> >>>>> It's really outrageous for them Powercrank to charge so much for a
> >>>>> faulty design.
>
> >>> "Tim McNamara" <[email protected]> wrote
> >>>> The proprietor of PowerCranks used to post here to rebut
> >>>> criticisms, but
> >>>> I haven't seen anything from him for a while. Basically I suspect
> >>>> that
> >>>> the price is high because (1) he promises that his product will
> >>>> make you
> >>>> faster for which competitive people will pay lots of money and (2)
> >>>> his
> >>>> business is small enough that he doesn't get much by way of
> >>>> economies of
> >>>> scale to bring his production costs down.
>
> >> "Phil Holman" <piholmanc@yourservice> wrote:
> >>> Frank Day. His last posts here were after a scientific study showed
> >>> a statistically significant 1.5% gross efficiency improvement. The
> >>> experts here still wouldn't buy it.
>
> > [email protected] wrote:
> >> No offense, but that sounds like 200 watts rising to 203 watts.
>
> > Wouldn't that be 200W reduced to a mere 197 watts?
>
> No, but I know what you are getting at. For the same 200 watt output,
> VO2 consumption reduces by 100*1.5/E = approx 6% less. From this we
> infer that for the same O2 consumption, the athlete can output 212
> watts.

Can that be safely inferred?

Andy Coggan

 

[Andy Coggan]

On Jun 7, 2:26 pm, Bill <[email protected]> wrote:

> The reason you can't hold your breath for more than about
> 2 minutes, even while sitting, is the CO2 buildup in the airways causing
> a forced breathing reflex.

And this relates to the *eucapnic* regulation of ventilation during
exercise how?

Andy Coggan

 

[Bill C]

On Jun 7, 3:26 pm, Bill <[email protected]> wrote:
> Andy Coggan wrote:
> > On Jun 5, 11:04 pm, "Phil Holman" <piholmanc@yourservice> wrote:
> >> <[email protected]> wrote in message
>
> >>> In recent times, steam RR locomotives, although not rated in Horse
> >>> Power (but rather "tractive effort", the pull at which the wheels
> >>> would spin) had a conversion chart to HP based on grate area in the
> >>> fire box which governs how much heat can be transferred to steam in
> >>> the boiler. Grate area is closely similar to lung displacement for
> >>> physically fit racers. That is what limits climbing or TT ability,
> >>> not ankling, pedaling style or other external means.
> >> You continue to repeat this misconception. Lung displacement or lung
> >> capacity is not the limiting factor in climbing or TTing or cycling in
> >> general. If you understood the cause and effect elements you would
> >> understand that extreme "out of breath" is caused by excess CO2 in the
> >> blood stream as a result of lactic buffering.
>
> > Great! Now we have one engineer feeding misconceptions about how
> > physiology functions to another engineer...
>
> > Fact: CO2 plays only a very limited role in regulating ventilation
> > during exercise.
>
> Another fact: The reason you can't hold your breath for more than about
> 2 minutes, even while sitting, is the CO2 buildup in the airways causing
> a forced breathing reflex.
> Even someone who is not working out can exercise the lungs, as I used to
> do during long car commutes. Inhale to the absolute maximum and hold for
> as long as possible. I gained some lung volume from doing that on long
> boring stretches of road. Sounds lame, but it worked.

Guess all those pearl divers were faking it since you have concluded
it's not possible. I think Andy might know a little more on the
subject and have a bit more credibility.
Bill C

 

[Howard Kveck]

In article <[email protected]>,
Andy Coggan <[email protected]> wrote:


> eucapnic

First use of this word in this group (rbr).

--
tanx,
Howard

Never take a tenant with a monkey.

remove YOUR SHOES to reply, ok?

 

[Bill]

Andy Coggan wrote:
> On Jun 7, 2:26 pm, Bill <[email protected]> wrote:
>
>> The reason you can't hold your breath for more than about
>> 2 minutes, even while sitting, is the CO2 buildup in the airways causing
>> a forced breathing reflex.
>
> And this relates to the *eucapnic* regulation of ventilation during
> exercise how?
>
> Andy Coggan
>
Eucapnic?????
Where's Webster's when I need it?
I was kind of shooting at having to hold your breath when riding in the
country and going through a cloud of dust, fertilizer, and whatever else
a tractor can put into the air you have to ride through.
Google leads to a wild goose chase on eucapnic. It isn't even in Webster's.
You win the oddball word contest.
Bill Baka

 

[Bill]

Bill C wrote:
> On Jun 7, 3:26 pm, Bill <[email protected]> wrote:
>> Even someone who is not working out can exercise the lungs, as I used to
>> do during long car commutes. Inhale to the absolute maximum and hold for
>> as long as possible. I gained some lung volume from doing that on long
>> boring stretches of road. Sounds lame, but it worked.
>
> Guess all those pearl divers were faking it since you have concluded
> it's not possible. I think Andy might know a little more on the
> subject and have a bit more credibility.
> Bill C
>
They just have more tolerance or determination. I did read that CO2
buildup in the lungs was a major trigger for the breathing reflex.
Some of those pearl divers go down and don't make it back up in good
shape. Tourists never hear about them.
Also, a minor correction. I never concluded it was impossible, just
improbable. My personal best is 3 minutes at the bottom of my pool.
My wife thought I drowned.
I know, darn, he didn't drown.
Bill Baka

 

[Phil Holman]

"Andy Coggan" <[email protected]> wrote in message
news:[email protected]...
> On Jun 3, 3:02 pm, "Phil Holman" <piholmanc@yourservice> wrote:
>
>> What does it take to get an appropriate and properly
>> designed test?
>
> Somebody who knows what they're doing? ;-)
>

You would think that quality would be more common than it is.

Phil H

 

[Phil Holman]

"Andy Coggan" <[email protected]> wrote in message
news:[email protected]...
> On Jun 5, 11:04 pm, "Phil Holman" <piholmanc@yourservice> wrote:
>> <[email protected]> wrote in message
>
>> > In recent times, steam RR locomotives, although not rated in Horse
>> > Power (but rather "tractive effort", the pull at which the wheels
>> > would spin) had a conversion chart to HP based on grate area in the
>> > fire box which governs how much heat can be transferred to steam in
>> > the boiler. Grate area is closely similar to lung displacement for
>> > physically fit racers. That is what limits climbing or TT ability,
>> > not ankling, pedaling style or other external means.
>>
>> You continue to repeat this misconception. Lung displacement or lung
>> capacity is not the limiting factor in climbing or TTing or cycling
>> in
>> general. If you understood the cause and effect elements you would
>> understand that extreme "out of breath" is caused by excess CO2 in
>> the
>> blood stream as a result of lactic buffering.
>
> Great! Now we have one engineer feeding misconceptions about how
> physiology functions to another engineer...

Ouch.

>
> Fact: CO2 plays only a very limited role in regulating ventilation
> during exercise.

My understanding is that there is an interrelationship between chemical
and neurogenic factors in the control of respiration.

>
>> That is, the limits of
>> aerobic capacity were reached upstream (cardiac output, blood muscle
>> interface limitations etc) and no further limitations are imposed by
>> the
>> lungs. It wouldn't matter if you doubled lung capacity, blood lactate
>> concentrations wouldn't change and this is the culminating event in
>> limiting aerobic performance. Heavy breathing is an effect not a
>> cause.
>
> In fact, mild-to-moderate arterial desaturation tends to occur during
> maximal exercise in a significant portion of the population (at least
> discounting young, healthy, untrained men!), indicating that, at least
> to some extent, aerobic capacity (i.e., VO2max) is limited, in part,
> by pulmonary function.

And do we see desaturation in disproportionate amounts with more
instances in lower performing athletes or do we see it evenly scattered
through the performance sprectrum. Much like VO2max in predicting
cycling performance, is lung capacity in the same category?

Phil H

 

[Phil Holman]

"Andy Coggan" <[email protected]> wrote in message
news:[email protected]...
> On Jun 3, 12:58 pm, "Phil Holman" <piholmanc@yourservice> wrote:
>
>> I just checked their website and found another study of trained
>> cyclists
>> that showed a 15.6% increase in VO2max and an 11.6% icrease in max
>> power.
>
> Yeah, training will do that for you (or at least it should).

I'm at a loss for the need to test for it. Controls would be nice.

>
> Andy Coggan (whose sustainable power is up 11% in the last 10 wk)
>
Good for you.

Phil H

 

[Phil Holman]

"Andy Coggan" <[email protected]> wrote in message
news:[email protected]...
> On Jun 3, 9:01 pm, "Phil Holman" <piholmanc@yourservice> wrote:
>> "A Muzi" <[email protected]> wrote in message
>>
>> news:[email protected]...
>>
>>
>>
>>
>>
>> >>>>> Ride Faster <[email protected]> wrote:
>> >>>>>> I had the same experience with PowerCranks. This product is
>> >>>>>> garbage.
>>
>> >>>> "[email protected]" <[email protected]> wrote:
>> >>>>> It's really outrageous for them Powercrank to charge so much
>> >>>>> for a
>> >>>>> faulty design.
>>
>> >>> "Tim McNamara" <[email protected]> wrote
>> >>>> The proprietor of PowerCranks used to post here to rebut
>> >>>> criticisms, but
>> >>>> I haven't seen anything from him for a while. Basically I
>> >>>> suspect
>> >>>> that
>> >>>> the price is high because (1) he promises that his product will
>> >>>> make you
>> >>>> faster for which competitive people will pay lots of money and
>> >>>> (2)
>> >>>> his
>> >>>> business is small enough that he doesn't get much by way of
>> >>>> economies of
>> >>>> scale to bring his production costs down.
>>
>> >> "Phil Holman" <piholmanc@yourservice> wrote:
>> >>> Frank Day. His last posts here were after a scientific study
>> >>> showed
>> >>> a statistically significant 1.5% gross efficiency improvement.
>> >>> The
>> >>> experts here still wouldn't buy it.
>>
>> > [email protected] wrote:
>> >> No offense, but that sounds like 200 watts rising to 203 watts.
>>
>> > Wouldn't that be 200W reduced to a mere 197 watts?
>>
>> No, but I know what you are getting at. For the same 200 watt output,
>> VO2 consumption reduces by 100*1.5/E = approx 6% less. From this we
>> infer that for the same O2 consumption, the athlete can output 212
>> watts.
>
> Can that be safely inferred?
>
I don't think it's too much of a stretch for a very small extrapolation.

Phil H