Beware of PowerCranks



"Bill" <[email protected]> wrote in message
news:[email protected]...

> Not judging by the quality of doctors in my corner of the world.
> I was just thinking that VO2 max might be due to a more efficient whole
> body system than just lung capacity. That takes my 30 second full blast
> runs out of the equation then. Is there an equivalent bicycle event like a
> quarter mile drag race that would be the equal in terms of full burner on
> the legs and wait for the pulse and lungs to catch up?


It's called a Wingate test.
 
On Jun 7, 11:35 pm, "Phil Holman" <piholmanc@yourservice> wrote:
> "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.


Actually, it is, because if efficiency were everything, we'd all be
riding at much slower cadences than we normally do.

"The best predictor of performance is performance itself"

Andy Coggan
 
"Andy Coggan" <[email protected]> wrote in message
news:[email protected]...
....
> Can that be safely inferred?

....
Safe inferences are highly overrated and tend to interfere in normal
conversation. We like to keep a low bar for inferences in rbr. Some of us,
of course, just want to keep a bar.


--
Curtis L. Russell
Odenton, MD (USA)
Just someone on two wheels...
 
"Bill" <[email protected]> wrote in message
news:[email protected]...
> 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.


Shimano had them. Each incarnation they move around the cranks a little bit
this way or that. On the Shimano design the "low" part of the rings were on
the top and bottom so that you could push through the dead spots easier. On
the rings they're using now it's different.
 
"Davey Crockett" <[email protected]> wrote in message
news:[email protected]...
>
> * 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


Interestingly - though the entire range of Shimano had Bio-Pace they didn't
put it on Dura Ace except for one year I think and the egg shaping was
almost non-existant on those rings.
 
Carl Sundquist wrote:
>
> "Bill" <[email protected]> wrote in message
> news:[email protected]...
>
>> Not judging by the quality of doctors in my corner of the world.
>> I was just thinking that VO2 max might be due to a more efficient
>> whole body system than just lung capacity. That takes my 30 second
>> full blast runs out of the equation then. Is there an equivalent
>> bicycle event like a quarter mile drag race that would be the equal in
>> terms of full burner on the legs and wait for the pulse and lungs to
>> catch up?

>
> It's called a Wingate test.


I just looked it up and that might be why my full tilt runs always run
out of gas at about 30 seconds. That's also about my maximum full out
attack time on the bike.
Interesting stuff, so now I have some reading to do.
Bill Baka
 
Andy Coggan wrote:
> On Jun 7, 6:35 pm, Howard Kveck <[email protected]> wrote:
>> In article <[email protected]>,
>> Andy Coggan <[email protected]> wrote:
>>
>>> eucapnic

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

>
> Seriously? Man, that's sad.
>
> Andy Coggan
>

Webster's doesn't have it (I checked) and Google comes up with some
strange hits, but it is most definitely not a mainstream word.
Not in the states, at least.
Bill Baka
 
In article
<[email protected]>,
Andy Coggan <[email protected]> wrote:

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


Where is this fact documented? Blood CO2 level has a
profound effect on ventilation. There is a mechanism in
the brain that senses blood pH. When pH falls the
mechanism increases breathing rate. When pH rises the
mechanism decreases breathing rate. It is a dominant
mechanism as is evident from the phenomenon known as
Cheyne-Stokes respiration where the feed-back mechanism
is involved in a pathological oscillation of breathing rate.

--
Michael Press
 
"Bill" <[email protected]> wrote in message
news:g%[email protected]...
> Carl Sundquist wrote:
>>
>> "Bill" <[email protected]> wrote in message
>> news:[email protected]...
>>
>>> Not judging by the quality of doctors in my corner of the world.
>>> I was just thinking that VO2 max might be due to a more efficient
>>> whole body system than just lung capacity. That takes my 30 second
>>> full blast runs out of the equation then. Is there an equivalent
>>> bicycle event like a quarter mile drag race that would be the equal
>>> in terms of full burner on the legs and wait for the pulse and lungs
>>> to catch up?

>>
>> It's called a Wingate test.

>
> I just looked it up and that might be why my full tilt runs always run
> out of gas at about 30 seconds. That's also about my maximum full out
> attack time on the bike.
> Interesting stuff, so now I have some reading to do.
> Bill Baka


You asked about an event. For the over 50s on the track, there is the
500m which from a standing start runs some 37 seconds or so depending on
your ability. Talk about eyeballs out.

Phil H
 
"Michael Press" <[email protected]> wrote in message
news:[email protected]...
> In article
> <[email protected]>,
> Andy Coggan <[email protected]> wrote:
>
>> Fact: CO2 plays only a very limited role in regulating ventilation
>> during exercise.

>
> Where is this fact documented? Blood CO2 level has a
> profound effect on ventilation. There is a mechanism in
> the brain that senses blood pH. When pH falls the
> mechanism increases breathing rate. When pH rises the
> mechanism decreases breathing rate. It is a dominant
> mechanism as is evident from the phenomenon known as
> Cheyne-Stokes respiration where the feed-back mechanism
> is involved in a pathological oscillation of breathing rate.
>

My understanding for strenous exercise is, there are the initial
collateral impulses which stimulate both the contracting muscles and the
respiratory center. There is actually an initial drop in PCO2. However
after about a minute when PCO2 reaches normal levels again, the
mechanism which you mention kicks in. PCO2 being the main driver over pH
and O2.

Phil H
 
"Andy Coggan" <[email protected]> wrote in message
news:[email protected]...
> On Jun 7, 11:35 pm, "Phil Holman" <piholmanc@yourservice> wrote:
>> "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.

>
> Actually, it is, because if efficiency were everything, we'd all be
> riding at much slower cadences than we normally do.


That just confuses the issue; we are not talking about a race to burn
fewest calories and the example used was at 70% effort. Anyhow, who
would pass up being more efficient at their max sustainble power output
and normal cadence etc.(which I know doesn't read over from this test
result).
>
> "The best predictor of performance is performance itself"


And no one is interested in why?

Phil H
 
Phil Holman wrote:
> "Bill" <[email protected]> wrote in message
> news:g%[email protected]...
>> Carl Sundquist wrote:
>>> "Bill" <[email protected]> wrote in message
>>> news:[email protected]...
>>>
>>>> Not judging by the quality of doctors in my corner of the world.
>>>> I was just thinking that VO2 max might be due to a more efficient
>>>> whole body system than just lung capacity. That takes my 30 second
>>>> full blast runs out of the equation then. Is there an equivalent
>>>> bicycle event like a quarter mile drag race that would be the equal
>>>> in terms of full burner on the legs and wait for the pulse and lungs
>>>> to catch up?
>>> It's called a Wingate test.

>> I just looked it up and that might be why my full tilt runs always run
>> out of gas at about 30 seconds. That's also about my maximum full out
>> attack time on the bike.
>> Interesting stuff, so now I have some reading to do.
>> Bill Baka

>
> You asked about an event. For the over 50s on the track, there is the
> 500m which from a standing start runs some 37 seconds or so depending on
> your ability. Talk about eyeballs out.
>
> Phil H
>
>

I just did it again, and I am waaay over 50, like 58, and didn't really
have to start heavy breathing until I was at about the 1,000 foot
finish. Of course I was still huffing and puffing all the way back, and
the really heavy breathing was only about 30 seconds after I was done
running. Eyeballs out almost describes it though, but I will run as long
as I am able, like maybe 90 or so, and the same with riding a bicycle.
My sister is 72 and still rides on occasion, but not regularly.
The trip odometer on my bike reads about 0.21 miles to the last point I
measured and I just went past that today on my second run. My runs may
or may not be as good as an hour long bike ride but I figure anything
that gets your heart working is a good thing.
Bill Baka
 
On 6/6/07 11:02 PM, in article
[email protected], "Bill" <[email protected]>
wrote:

> 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


BioPace
 
Tim McNamara wrote:
> In article <[email protected]>,
> Andy Coggan <[email protected]> wrote:
>
>> On Jun 7, 6:35 pm, Howard Kveck <[email protected]> wrote:
>>> In article <[email protected]>,
>>> Andy Coggan <[email protected]> wrote:
>>>
>>>> eucapnic
>>> First use of this word in this group (rbr).

>> Seriously? Man, that's sad.

>
> But isn't it correctly spelled "eucapneic?" There are at least zero
> hits on Google for "eucapnic" and 309 hits for "eucapneic."



http://www.merriam-webster.com/dictionary/eucapneic

Not found here.
Is this an intentional wild goose chase?
BB
 
ST wrote:
> On 6/6/07 11:02 PM, in article
> [email protected], "Bill" <[email protected]>
> wrote:
>
>> 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

>
> BioPace
>

Bingo!
Since they seem to pop up every what?..20 years or so can one safely say
that if you don't know your history you are doomed to repeat it?
I would be surprised if the Patent office actually has something like
this every 20 years or so, unless the USPTO is really incompetent.
Maybe I can patent the wheel?
Bill Baka
 
On Fri, 08 Jun 2007 19:39:40 -0500, Tim McNamara
<[email protected]> wrote:

>In article <[email protected]>,
> Andy Coggan <[email protected]> wrote:
>
>> On Jun 7, 6:35 pm, Howard Kveck <[email protected]> wrote:
>> > In article <[email protected]>,
>> > Andy Coggan <[email protected]> wrote:
>> >
>> > > eucapnic
>> >
>> > First use of this word in this group (rbr).

>>
>> Seriously? Man, that's sad.

>
>But isn't it correctly spelled "eucapneic?" There are at least zero
>hits on Google for "eucapnic" and 309 hits for "eucapneic."


Dear Tim,

Try the related eucapnia:

http://cancerweb.ncl.ac.uk/cgi-bin/omd?query=eucapnia&action=Search+OMD

Cheers,

Carl Fogel
 
"Phil Holman" <piholmanc@yourservice> wrote in message
news:[email protected]...
>
> "Michael Press" <[email protected]> wrote in message
> news:[email protected]...
>> In article
>> <[email protected]>,
>> Andy Coggan <[email protected]> wrote:
>>
>>> Fact: CO2 plays only a very limited role in regulating ventilation
>>> during exercise.

>>
>> Where is this fact documented? Blood CO2 level has a
>> profound effect on ventilation. There is a mechanism in
>> the brain that senses blood pH. When pH falls the
>> mechanism increases breathing rate. When pH rises the
>> mechanism decreases breathing rate. It is a dominant
>> mechanism as is evident from the phenomenon known as
>> Cheyne-Stokes respiration where the feed-back mechanism
>> is involved in a pathological oscillation of breathing rate.
>>

> My understanding for strenous exercise is, there are the initial
> collateral impulses which stimulate both the contracting muscles and the
> respiratory center. There is actually an initial drop in PCO2. However
> after about a minute when PCO2 reaches normal levels again, the mechanism
> which you mention kicks in. PCO2 being the main driver over pH and O2.


When your cellular and blood levels of CO2 rise you begin breathing faster.
Unfortunately for you, oxygen has a high priority in your blood stream and
so as you breath harder your expiration of CO2 remains pretty much constant
despite increased demand. As you breath harder the blood picks up more
oxygen and takes up all the space that CO2 wants.

So all that puffing and panting isn't to get more oxygen but to get rid of
more CO2.