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  #11  
Old November 26th 18, 05:53 PM posted to rec.bicycles.tech
Claus A▀mann
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Posts: 12
Default Power Meter

Your riding position changes remarkably little if you are riding hard.

Ah, thanks for telling me. I guess I'm doing something wrong then,
as I'm riding in different positions when going uphill compared to
flat/downhill.

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  #12  
Old November 26th 18, 06:12 PM posted to rec.bicycles.tech
[email protected]
external usenet poster
 
Posts: 493
Default Power Meter

On Monday, November 26, 2018 at 8:53:49 AM UTC-8, Claus A├čmann wrote:
Your riding position changes remarkably little if you are riding hard.


Ah, thanks for telling me. I guess I'm doing something wrong then,
as I'm riding in different positions when going uphill compared to
flat/downhill.


But the much lower speed reduces the aerodynamic drag which is logarithmic rather than linear. Again - can you explain why rear hub stress gauges do not find a remarkable difference between power output and speed compared to grade?

Are you a Pro who can climb 12% at 15 mph?
  #13  
Old November 27th 18, 12:04 AM posted to rec.bicycles.tech
Jeff Liebermann
external usenet poster
 
Posts: 2,928
Default Power Meter

On Mon, 26 Nov 2018 13:49:08 +0000 (UTC), Ralph Barone
wrote:

There are still a number of unanswered questions, which is why they don't
have my money yet. Like all new product development projects, they're
behind schedule, and they haven't provided enough real world test data to
keep all the backers happy. However, the price point (160 Euro each, 260
Euro for a pair) is lower than any other direct measuring power meter out
there.


Sorry, but I have no delivery information or current interest in their
business practices. I'm interested in the technology. As Jay has so
eloquently noted, they're a Kickstarter startup and have a high
probability of failings. A good clue is that they collected 10 times
the money that they were trying to attract, which means they either
don't understand the market, or have grossly underpriced their
product. I suspect the latter.

Methinks it maketh more sense to put the sensors in the riders shoes,
rather than in the pedals. It would be easier to build, would
indicate the power delivered by the riders feet instead of the pedals,
and could be used for other power measurements, such as running. One
would only need one power meter sensor pair for the shoes, not one for
each bicycle. Something like this:
https://www.dcrainmaker.com/2016/09/lucks-cycling-power-meter-shoe.html
Well, maybe not. No sign of a power meter on their web pile:
https://luck-bike.es/en/



--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
  #14  
Old November 27th 18, 02:48 AM posted to rec.bicycles.tech
Claus A▀mann
external usenet poster
 
Posts: 12
Default Power Meter

Are you a Pro who can climb 12% at 15 mph?

Which professional cyclist can climb 12% at 24 km/h?
Do you mean for 1 minute?

That seems to require about 10 W/kg
Or maybe this calculator is wrong: BikePower-0.33:
grade of hill = 12.0% headwind = 0.0 kph
rolling friction coeff = 0.0047 BM rate = 1.40 W/kg
air resistance coeff = (0.2670, 0)
efficiency: transmission = 98.0% human = 24.9%

What's the required W/kg based on your calculations
(and which input data do you use)?


--
Note: please read the netiquette before posting. I will almost never
reply to top-postings which include a full copy of the previous
article(s) at the end because it's annoying, shows that the poster
is too lazy to trim his article, and it's wasting the time of all readers.
  #15  
Old November 27th 18, 02:58 AM posted to rec.bicycles.tech
Ralph Barone[_4_]
external usenet poster
 
Posts: 200
Default Power Meter

Jeff Liebermann wrote:
On Mon, 26 Nov 2018 13:49:08 +0000 (UTC), Ralph Barone
wrote:

There are still a number of unanswered questions, which is why they don't
have my money yet. Like all new product development projects, they're
behind schedule, and they haven't provided enough real world test data to
keep all the backers happy. However, the price point (160 Euro each, 260
Euro for a pair) is lower than any other direct measuring power meter out
there.


Sorry, but I have no delivery information or current interest in their
business practices. I'm interested in the technology. As Jay has so
eloquently noted, they're a Kickstarter startup and have a high
probability of failings. A good clue is that they collected 10 times
the money that they were trying to attract, which means they either
don't understand the market, or have grossly underpriced their
product. I suspect the latter.

Methinks it maketh more sense to put the sensors in the riders shoes,
rather than in the pedals. It would be easier to build, would
indicate the power delivered by the riders feet instead of the pedals,
and could be used for other power measurements, such as running. One
would only need one power meter sensor pair for the shoes, not one for
each bicycle. Something like this:
https://www.dcrainmaker.com/2016/09/lucks-cycling-power-meter-shoe.html
Well, maybe not. No sign of a power meter on their web pile:
https://luck-bike.es/en/



Hell, Jeff, just get some strain gauges surgically inserted in your tibias,
and you're halfway to the universal power meter. Tie some piezoelectric
generators to your Achilles' tendon for power, add a bit of DSP and a
BlueTooth stack and you're cooking with gas! Maybe run a power lead up to
the chest to power the internal HRM for extra points.

  #16  
Old November 27th 18, 06:38 AM posted to rec.bicycles.tech
Jeff Liebermann
external usenet poster
 
Posts: 2,928
Default Power Meter

On Tue, 27 Nov 2018 01:58:16 +0000 (UTC), Ralph Barone
wrote:

Hell, Jeff, just get some strain gauges surgically inserted in your tibias,
and you're halfway to the universal power meter. Tie some piezoelectric
generators to your Achilles' tendon for power, add a bit of DSP and a
BlueTooth stack and you're cooking with gas! Maybe run a power lead up to
the chest to power the internal HRM for extra points.


The Bionic Bicyclist? I may already have some of that installed. I
recently had to have a CT scan to locate two big kidney boulders that
are currently trying to kill me. Among the medical terminology was
mention of the electrodes that the surgeon left attached to my heart
in 2003 after a triple heart bypass operation. All I need to do is
locate the wires, and I might be able to monitor my heart performance
and loading. Cyborgs-R-Us.

Among my many predictions that never happened, I had somehow decided
that wearable computing was going to be the next big thing. I don't
recall the exact year, but I'll guess about 2008. Computers had
become small and low power enough to be wearable. Like my mythical
fully instrumented bicycle, all that was needed was a way for all the
devices and sensors to communicate, and a safe way to power those that
need power. Never mind what the result looked like. The early
bicycles, automobiles, and airplanes were also rather odd looking.

So, I ran a few experiments, did some paper designs, tried to sell a
few ideas, but mostly waited for something to happen. Nothing
happened. Nobody wanted to wear a computer. The demise of Google
Glass and the luke warm reception of the various smar****ches largely
ended my optimism. When I tried to raise the "wired bicycle" concept
in rec.bicycles.tech, the general reception was dismal. When I tried
to minimize the involvement to just making measurements and data
logging, most of the comments were something like "we don't need no
stinkin numbers. Just go for a ride and try it. If it's any good,
I'll let you know".

The next logical step after wearable computing would have been
cybernetic attachments, such as the implants you describe. However,
without the aid of the intermediate step of wearable computers, it
will never happen.

Drivel: I just got out of the hospital after a failed laser
lithotripsy trying to remove a rather large kidney stone. We try
again in 3 weeks. After I recover, we do the stone on the other side.
I'm ok, no pain, but also no bicycle riding.

Bah Humbug (T'is the season).


--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
  #17  
Old November 27th 18, 02:39 PM posted to rec.bicycles.tech
Ralph Barone[_4_]
external usenet poster
 
Posts: 200
Default Power Meter

Jeff Liebermann wrote:
On Tue, 27 Nov 2018 01:58:16 +0000 (UTC), Ralph Barone
wrote:

Hell, Jeff, just get some strain gauges surgically inserted in your tibias,
and you're halfway to the universal power meter. Tie some piezoelectric
generators to your Achilles' tendon for power, add a bit of DSP and a
BlueTooth stack and you're cooking with gas! Maybe run a power lead up to
the chest to power the internal HRM for extra points.


The Bionic Bicyclist? I may already have some of that installed. I
recently had to have a CT scan to locate two big kidney boulders that
are currently trying to kill me. Among the medical terminology was
mention of the electrodes that the surgeon left attached to my heart
in 2003 after a triple heart bypass operation. All I need to do is
locate the wires, and I might be able to monitor my heart performance
and loading. Cyborgs-R-Us.

Among my many predictions that never happened, I had somehow decided
that wearable computing was going to be the next big thing. I don't
recall the exact year, but I'll guess about 2008. Computers had
become small and low power enough to be wearable. Like my mythical
fully instrumented bicycle, all that was needed was a way for all the
devices and sensors to communicate, and a safe way to power those that
need power. Never mind what the result looked like. The early
bicycles, automobiles, and airplanes were also rather odd looking.

So, I ran a few experiments, did some paper designs, tried to sell a
few ideas, but mostly waited for something to happen. Nothing
happened. Nobody wanted to wear a computer. The demise of Google
Glass and the luke warm reception of the various smar****ches largely
ended my optimism. When I tried to raise the "wired bicycle" concept
in rec.bicycles.tech, the general reception was dismal. When I tried
to minimize the involvement to just making measurements and data
logging, most of the comments were something like "we don't need no
stinkin numbers. Just go for a ride and try it. If it's any good,
I'll let you know".

The next logical step after wearable computing would have been
cybernetic attachments, such as the implants you describe. However,
without the aid of the intermediate step of wearable computers, it
will never happen.

Drivel: I just got out of the hospital after a failed laser
lithotripsy trying to remove a rather large kidney stone. We try
again in 3 weeks. After I recover, we do the stone on the other side.
I'm ok, no pain, but also no bicycle riding.

Bah Humbug (T'is the season).


Good luck with the kidney stone, Jeff. Mine was the absolute best case
scenario, but it still wasn't fun.

  #18  
Old November 27th 18, 07:27 PM posted to rec.bicycles.tech
[email protected]
external usenet poster
 
Posts: 493
Default Power Meter

On Monday, November 26, 2018 at 5:48:04 PM UTC-8, Claus A├čmann wrote:
Are you a Pro who can climb 12% at 15 mph?


Which professional cyclist can climb 12% at 24 km/h?
Do you mean for 1 minute?

That seems to require about 10 W/kg
Or maybe this calculator is wrong: BikePower-0.33:
grade of hill = 12.0% headwind = 0.0 kph
rolling friction coeff = 0.0047 BM rate = 1.40 W/kg
air resistance coeff = (0.2670, 0)
efficiency: transmission = 98.0% human = 24.9%

What's the required W/kg based on your calculations
(and which input data do you use)?


--
Note: please read the netiquette before posting. I will almost never
reply to top-postings which include a full copy of the previous
article(s) at the end because it's annoying, shows that the poster
is too lazy to trim his article, and it's wasting the time of all readers..


I don't think you understood what I was saying - your position climbing on a bike is pretty much irrelevant to the aerodynamic drag because that is a logarithmic growth curve. Until you get over 13 mph or so the rolling resistance is the major drag on a drop bar road bike.

If you don't like the design of these devices by all means do not buy them. But also do not argue with me that inconsequential details make them unusable if you don't mind.
  #19  
Old November 29th 18, 06:54 PM posted to rec.bicycles.tech
[email protected]
external usenet poster
 
Posts: 493
Default Power Meter

On Monday, November 26, 2018 at 5:48:04 PM UTC-8, Claus A├čmann wrote:
Are you a Pro who can climb 12% at 15 mph?


Which professional cyclist can climb 12% at 24 km/h?
Do you mean for 1 minute?

That seems to require about 10 W/kg
Or maybe this calculator is wrong: BikePower-0.33:
grade of hill = 12.0% headwind = 0.0 kph
rolling friction coeff = 0.0047 BM rate = 1.40 W/kg
air resistance coeff = (0.2670, 0)
efficiency: transmission = 98.0% human = 24.9%

What's the required W/kg based on your calculations
(and which input data do you use)?


--
Note: please read the netiquette before posting. I will almost never
reply to top-postings which include a full copy of the previous
article(s) at the end because it's annoying, shows that the poster
is too lazy to trim his article, and it's wasting the time of all readers..


By the way Claus please don't take my comments too seriously. I'm on several forums with total idiots and I come over here after getting really irritated by people who throw around words like Stefan-Bo9ltzmann Constant and then say that you can't measure the temperature of a body by looking at it's spectroscopic cross section. Uh, that is what the Stefan-Boltzmann law is about.

So when I get here I'm often too harsh with people. I should have just said that I pulled those numbers out of the air just as an example.
 




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