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Corima - power meter 'embedded in wheel'
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Not often my day job overlaps with triathlon, but I spotted this and didn't see anything on searching the forum...

http://www.businesswire.com/news/home/20140626005707/en/CEA-Leti-CORIMA-Team-Force-Sensors-Integrated-Cycle#.U-x1ITk1jtw


CEA-Leti and CORIMA Team up on Force Sensors Integrated in Cycle Wheels to Measure Rider Power Output
June 26, 2014 09:11 AM Eastern Daylight Time
GRENOBLE, France--(BUSINESS WIRE)--CEA-Leti and CORIMA, a leading supplier of carbon-composite wheels and frames for track and road-racing cyclists, today announced they are developing an integrated sensor system to measure the power output of riders as they pedal.
“This force sensor developed with Leti and embedded on our carbon wheels is made with those athletes in mind and will raise the standard for measuring pedal force.”

While there are a variety of ways to measure this key parameter for serious riders, they typically use sensors affixed to pedals or the rear-wheel axis. The compact, ultra-light force sensor developed in this collaboration will be lighter, more precise and more easily integrated in the rear wheel, assuring reliable data in all types of weather and on all roads.
“CORIMA has always worked with cycling professionals on both the track and road racing circuits, so we understand their needs for superior equipment and, increasingly, smart devices,” said CORIMA Managing Director Pierre-Jean Martin. “This force sensor developed with Leti and embedded on our carbon wheels is made with those athletes in mind and will raise the standard for measuring pedal force.”
The project blends Leti’s expertise in electronics, signal processing and wireless communication to transmit real-time information via the Internet of Things about the cyclist’s pedal force. CORIMA masters for its part the modelling of the distributions of effort in the wheel.
The project is part of Leti’s Development and Prototyping Platform, whose goal is to help SMEs in traditional industries improve their products and develop competitive advantages by integrating sensors and communication systems in their products. It is funded through the Easytech program of the IRT Nanoelec research institute.
“Leti’s strengths in microelectronics and sensors produce versatile devices that have many potential uses, and we constantly look for potential partners who have new applications for them,” said Leti CEO Laurent Malier. “Working with CORIMA, our team came up with an innovative use for a force sensors that, when integrated in CORIMA’s carbon wheels, apply Leti technology in a new realm and support the quantify-self movement.”
About CEA-Leti
By creating innovation and transferring it to industry, Leti is the bridge between basic research and production of micro- and nanotechnologies that improve the lives of people around the world. Backed by its portfolio of 2,200 patents, Leti partners with large industrials, SMEs and startups to tailor advanced solutions that strengthen their competitive positions. It has launched more than 50 startups. Its 8,000m² of new-generation cleanroom space feature 200mm and 300mm wafer processing of micro and nano solutions for applications ranging from space to smart devices. Leti’s staff of more than 1,700 includes 200 assignees from partner companies. Leti is based in Grenoble, France, and has offices in Silicon Valley, Calif., and Tokyo. Visit www.leti.fr for more information.
About CORIMA
CORIMA was founded in 1973 by Pierre Martin and Jean-Marie Riffard and is based in Loriol, France. The word CORIMA is taken from COoperation RIffard MArtin. Its initial activities were mechanical moulding: the making of moulds and models for the foundry, automobile and aeronautics sectors. In 1988, CORIMA diversified into the production of carbon composite parts and launched its first product for the cycling sector, the “Disc Wheel”. This was followed by many other products... to create a full range of carbon products for cycling. CORIMA has always worked with cycling professionals on both the track and road-racing circuits. Its products have been involved in many prestigious victories and setting of new records around the world and continue to do so with numerous athletes. For example, CORIMA carbon wheels won the Classic Cycling Race “Liège-Bastogne-Liège” in 2012, the Olympic Gold Medal of Road Cycling in 2012 and the Giro d’Italia in 2013
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Re: Corima - power meter 'embedded in wheel' [TOMOP] [ In reply to ]
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TOMOP wrote:
[..] For example, CORIMA carbon wheels won the Classic Cycling Race “Liège-Bastogne-Liège” in 2012, the Olympic Gold Medal of Road Cycling in 2012 and the Giro d’Italia in 2013
how 'bout this one race in France this year, supposedly important, was all over the news...?

if you can read this
YOU'RE DRAFTING!
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Re: Corima - power meter 'embedded in wheel' [TOMOP] [ In reply to ]
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Same issue as the powertap.
One set of wheels for the rollers
One set for general training
One set of race wheels.

Nope. I'll still with crank based.
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Re: Corima - power meter 'embedded in wheel' [Danielg] [ In reply to ]
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And why can't you use the same wheel for all of those options?
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Re: Corima - power meter 'embedded in wheel' [BMANX] [ In reply to ]
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BMANX wrote:
And why can't you use the same wheel for all of those options?

For me, it's not just the wheels but the tires as well. Changing tires is a much bigger PITA than changing wheels. So I have 4 sets of wheels, all interchangeable between road and TT bike, all with a different tire set-up:
- Race wheels, with race tires and latex tubes, which literally only have warm-up and race miles on them
- 2 sets of training/commuter wheels, decent quality basic wheels with a high spoke count, with some good puncture resistant tires with a bit of tread on them
- Indoor wheels, an old set of Bontragers that came stock with my road bike, running tires which have punctured a few times on the open road but still good enough for the rollers

If it wasn't for the tires, I could see myself using one set of wheels for racing, training and indoors (would still want something cheaper and sturdier for commuting), but I'd never want to train on my race tires or race on my training tires, and given that I can change a wheel in maybe a quarter of the time it takes me to change a tire, this works out much better for me. Also gives that nice race day boost of putting on your race wheels and getting an instant boost in speed.
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Re: Corima - power meter 'embedded in wheel' [Danielg] [ In reply to ]
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And that only works if you have 1 bike. (Swapping cranks takes way longer than swapping wheels).

There's still no silver bullet...

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Re: Corima - power meter 'embedded in wheel' [flogazo] [ In reply to ]
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flogazo wrote:
TOMOP wrote:
[..] For example, CORIMA carbon wheels won the Classic Cycling Race “Liège-Bastogne-Liège” in 2012, the Olympic Gold Medal of Road Cycling in 2012 and the Giro d’Italia in 2013

how 'bout this one race in France this year, supposedly important, was all over the news...?

Press release was from June
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Re: Corima - power meter 'embedded in wheel' [BMANX] [ In reply to ]
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BMANX wrote:
And why can't you use the same wheel for all of those options?

On a budget, you can, but some hassle is involved as ideally you will be switching tires a lot if you do that, also you will be more likely to have a wheel wear issue on or near race day which is stressfull. I have for instance once popped a spoke in the middle of a stage race, and once had the bearing go bad just before a stage race.

most people will have less issues with this than I did, since I was doing full time bike training and my wife used the wheel as well, so it saw a lot of use.

So, it is nice to have two powertaps, which costs similarly as some of the better crank based options. Crank is nice for wheel flexibility but harder to swap between bikes...so, you could get two crank based ones =)



Kat Hunter reports on the San Dimas Stage Race from inside the GC winning team
Aeroweenie.com -Compendium of Aero Data and Knowledge
Freelance sports & outdoors writer Kathryn Hunter
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Re: Corima - power meter 'embedded in wheel' [BMANX] [ In reply to ]
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BMANX wrote:
And why can't you use the same wheel for all of those options?

Changing wheels is a whole lot easier than changing tires.
My choice. Yours might be different, so be it. I'll stick with crank based power and multiple wheels.
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Re: Corima - power meter 'embedded in wheel' [ZackCapets] [ In reply to ]
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ZackCapets wrote:
And that only works if you have 1 bike. (Swapping cranks takes way longer than swapping wheels).

There's still no silver bullet...

Nope. Quarq on the tri bike, Power2Max on the road bike.

Why swap?
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Re: Corima - power meter 'embedded in wheel' [Danielg] [ In reply to ]
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>>There's still no silver bullet...

>Nope. Quarq on the tri bike, Power2Max on the road bike.

>Why swap?


Cash is always the silver bullet.
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Re: Corima - power meter 'embedded in wheel' [Danielg] [ In reply to ]
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Ah...well if you have 2 crank-based PM's you're not saving much money relative to 2 wheel based PMS...

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Re: Corima - power meter 'embedded in wheel' [ZackCapets] [ In reply to ]
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ZackCapets wrote:
Ah...well if you have 2 crank-based PM's you're not saving much money relative to 2 wheel based PMS...


Or probably even compared to 3 wheel based PMS
Last edited by: TOMOP: Aug 14, 14 9:34
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Re: Corima - power meter 'embedded in wheel' [ZackCapets] [ In reply to ]
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ZackCapets wrote:
Ah...well if you have 2 crank-based PM's you're not saving much money relative to 2 wheel based PMS...

But my baseline for my roadbike is always the same and the baseline for my tri bike is always the same. I'm always comparing the same meter to itself over time.

Can't say that with multiple wheelsets with powermeters built in unless you only compare one wheel against itself only and not against the others. That throws a monkey wrench into the switch to race wheels and know what power readings you're looking for. You would have only other races to use for the comparison. Doesn't make sense.

As I said above, my choice. Make your own and it'll be just as right for you as this is for me.
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Re: Corima - power meter 'embedded in wheel' [Danielg] [ In reply to ]
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That isn't a problem at all, because the most important thing in power meter ownership is that you have an accurate one in the first place.


Danielg wrote:
Can't say that with multiple wheelsets with powermeters built in unless you only compare one wheel against itself only and not against the others. That throws a monkey wrench into the switch to race wheels and know what power readings you're looking for. You would have only other races to use for the comparison. Doesn't make sense.



Kat Hunter reports on the San Dimas Stage Race from inside the GC winning team
Aeroweenie.com -Compendium of Aero Data and Knowledge
Freelance sports & outdoors writer Kathryn Hunter
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Re: Corima - power meter 'embedded in wheel' [ZackCapets] [ In reply to ]
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ZackCapets wrote:
And that only works if you have 1 bike. (Swapping cranks takes way longer than swapping wheels).


There's still no silver bullet...

I can swap my crank between my road bike and tri bike in about 5 minutes and that's not even rushing. Changing wheels requires changing tires. I just switched from PT to Quarq last month and LOVE ease of use between my bikes.

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The curious task of economics is to demonstrate to men how little they really know about what they imagine they can design.
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Re: Corima - power meter 'embedded in wheel' [TheGupster] [ In reply to ]
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I pity the fool who buys 2 sets wheels but can only afford one tire.

Weak...

__________________________

I tweet!

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Re: Corima - power meter 'embedded in wheel' [jackmott] [ In reply to ]
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jackmott wrote:
That isn't a problem at all, because the most important thing in power meter ownership is that you have an accurate one in the first place.


Danielg wrote:
Can't say that with multiple wheelsets with powermeters built in unless you only compare one wheel against itself only and not against the others. That throws a monkey wrench into the switch to race wheels and know what power readings you're looking for. You would have only other races to use for the comparison. Doesn't make sense.

But most makes of power meter are not accurate, and even the most accurate are not always accurate.

If you don't agree post some independent scientific studies which prove the accuracy of the makes of power meters you think are accurate.

Even if as accurate as the manufacturers claim they are still only about +\ - 2% accurate which is 1 minute 12 seconds / 60 minutes. So not really much use measuring improvements in performance of 0.5%.
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Re: Corima - power meter 'embedded in wheel' [Evangelist] [ In reply to ]
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Evangelist wrote:
jackmott wrote:
That isn't a problem at all, because the most important thing in power meter ownership is that you have an accurate one in the first place.


Danielg wrote:
Can't say that with multiple wheelsets with powermeters built in unless you only compare one wheel against itself only and not against the others. That throws a monkey wrench into the switch to race wheels and know what power readings you're looking for. You would have only other races to use for the comparison. Doesn't make sense.

But most makes of power meter are not accurate, and even the most accurate are not always accurate.

If you don't agree post some independent scientific studies which prove the accuracy of the makes of power meters you think are accurate.

Even if as accurate as the manufacturers claim they are still only about +\ - 2% accurate which is 1 minute 12 seconds / 60 minutes. So not really much use measuring improvements in performance of 0.5%.

Could you post an independent study indicating that your power meter is self consistent over time? In other words, do you understand where the errors in a pm come from?
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Re: Corima - power meter 'embedded in wheel' [Evangelist] [ In reply to ]
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The quoted 2% error is normally a fairly random error around a mean. Two properly calibrated powertaps/srms etc will have that 2% error around the same mean. You can verify the calibration of any good power meter by hanging known masses off the pedals.

If you have a power meter that is not accurate, there are two possible reasons:

1. it is not calibrated, or is broken, in which case you either send it in to be fixed/calibrated or calibrate it yourself

2. It is inconsistent (for example, stages)

In either case, if you are hoping to monitor small performance improvements, an inaccurate power meter will not do the job, either because it is not consistent, or because it is no longer calibrated or is broken.

Hear me now believe me later, buy a good meter, check it's accuracy. If you can't be bothered, save you money and buy good tires instead. or coke.






Evangelist wrote:
But most makes of power meter are not accurate, and even the most accurate are not always accurate.

If you don't agree post some independent scientific studies which prove the accuracy of the makes of power meters you think are accurate.

Even if as accurate as the manufacturers claim they are still only about +\ - 2% accurate which is 1 minute 12 seconds / 60 minutes. So not really much use measuring improvements in performance of 0.5%.



Kat Hunter reports on the San Dimas Stage Race from inside the GC winning team
Aeroweenie.com -Compendium of Aero Data and Knowledge
Freelance sports & outdoors writer Kathryn Hunter
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Re: Corima - power meter 'embedded in wheel' [Evangelist] [ In reply to ]
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You keep using that word (accuracy). I do not think it means what you think it means.

Hint: there are a LOT of ways to get +/- 2% instrument accuracy that would have your 60 minutes looking more like 59 minutes 59.98 seconds (assuming 1 second sampling rate).


You really need to go back to some statistics/numerical analysis classes and understand how these instruments work. 0.5% improvements in performance can readily be detected if the inaccuracies are well characterized (and systemic biases eliminated) with a tool that claims +/- 2% accuracy. Depends on the control of the test environment and the breadth of samples.

The question of who is right and who is wrong has seemed to me always too small to be worth a moment's thought, while the question of what is right and what is wrong has seemed all-important.

-Albert J. Nock
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Re: Corima - power meter 'embedded in wheel' [jackmott] [ In reply to ]
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jackmott wrote:
The quoted 2% error is normally a fairly random error around a mean. Two properly calibrated powertaps/srms etc will have that 2% error around the same mean. You can verify the calibration of any good power meter by hanging known masses off the pedals.

If you have a power meter that is not accurate, there are two possible reasons:

1. it is not calibrated, or is broken, in which case you either send it in to be fixed/calibrated or calibrate it yourself

2. It is inconsistent (for example, stages)

In either case, if you are hoping to monitor small performance improvements, an inaccurate power meter will not do the job, either because it is not consistent, or because it is no longer calibrated or is broken.

Hear me now believe me later, buy a good meter, check it's accuracy. If you can't be bothered, save you money and buy good tires instead. or coke.






Evangelist wrote:
But most makes of power meter are not accurate, and even the most accurate are not always accurate.

If you don't agree post some independent scientific studies which prove the accuracy of the makes of power meters you think are accurate.

Even if as accurate as the manufacturers claim they are still only about +\ - 2% accurate which is 1 minute 12 seconds / 60 minutes. So not really much use measuring improvements in performance of 0.5%.

Yes we all know that, but just because you calibrate the power meter stationary hanging weights at zero rpm does not mean it is accurate at 90 rpm or after 5 minutes or 10 minutes or 20 minutes.
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Re: Corima - power meter 'embedded in wheel' [Derf] [ In reply to ]
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Derf wrote:
You keep using that word (accuracy). I do not think it means what you think it means.

Hint: there are a LOT of ways to get +/- 2% instrument accuracy that would have your 60 minutes looking more like 59 minutes 59.98 seconds (assuming 1 second sampling rate).


You really need to go back to some statistics/numerical analysis classes and understand how these instruments work. 0.5% improvements in performance can readily be detected if the inaccuracies are well characterized (and systemic biases eliminated) with a tool that claims +/- 2% accuracy. Depends on the control of the test environment and the breadth of samples.


Straws, clutching, desperate. Re read what you have posted, think about it.

People use power meters on the open road where the environment is totally uncontrolled.

Your post might be relevant if the power meter were used in a controlled environment.
Last edited by: Evangelist: Aug 14, 14 13:38
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Re: Corima - power meter 'embedded in wheel' [Evangelist] [ In reply to ]
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I have a pretty good grasp on what I wrote. "Straws, clutching, desperate"? Really!?


What is the environment of a powermeter? Temperature is the major confounding factor, and it's pretty well characterized, along with the built-in compensation mechanisms of different PMs. Bridge-style strain gauges are pretty stable, especially with the small temp range experienced in a ride: http://www.ni.com/...-paper/3432/en/#toc2. Reseting the zero point regularly within a ride (as the better PMs do) does well to reduce this bias.

So, yes, running a powertap straight up the side of a mountain (no coasting) with a 20-30 degree temperature gradient is going to throw things off. Doing a twenty minute warmup, then reseting the zero point before starting one's intervals? You can be pretty confident it's good data.

You're throwing the baby out with the bathwater if you're suggesting that these devices fall apart when you go out and ride the bike.

The question of who is right and who is wrong has seemed to me always too small to be worth a moment's thought, while the question of what is right and what is wrong has seemed all-important.

-Albert J. Nock
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Re: Corima - power meter 'embedded in wheel' [ZackCapets] [ In reply to ]
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ZackCapets wrote:
I pity the fool who buys 2 sets wheels but can only afford one tire.

Weak...


I don't think anyone mentioned cost of tires as an issue. Someone who buys a crank based power meter and two wheelsets is surely not doing so because of cost.
Last edited by: Jason N: Aug 14, 14 13:44
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