Power meter for rowing machine??

[seneka21]

After a thorough though fruitless web search for a power meter in the form of handlebar, handlebar attachment or handlebar to chain linking device I decided to ask for help from the community. My point is to find a way to measure Athlete's power output at the level of handlebar so that bypassing any unmeasured energy losses in the system. Any ideas or information would be welcome. All the best to the community. 

[Citroen]

You've got a big fat Performance Monitor (PM5) in front of your nose on a Concept2 rower.
Combine that with Ergdata on your phone and you're getting everything you desire.

[seneka21]

Thanks for the prompt response.
Unfortunatelly for some reason I dont have
In any case it would be greatly appreciated (and much more practical) if staying in
the context of the query which is about a power meter that gauges Athlete's power output
at the level of handlebar and definitely not about any kind of PM

Have a nice day

[Citroen]

You aren't making any sense.

All Concept2 rowers from the 2003 have a performance monitor that includes the force curve (which is a direct indication of your power). Those data is also available on the CSAFE API. For PMs that can connect to a phone running Ergdata or to a laptop running RowPro those data are also available there.

https://www.concept2.com/service/monito ... orce-curve

[Nomath]

If you want to measure power at the handlebar, you'll need both a force sensor and a speed or displacement sensor (power = force x speed). There are more than a handful of scientific studies in which such sensors were added to the C2 erg.
A study specifically adressing the discrepancy between power measured at the flywheel and power at the handlebar was done by S. Boyas and coauthors. Their paper Power Responses of a Rowing Ergometer: Mechanical Sensors vs Concept2 Measurement System was published in the Int. Journal of Sports Medicine, 2006.
They found that the C2 system underestimates the power produced by the rower by approximately 25W. This difference seems to be independent of the level of the power developed, but increases with variations in intensity and pace.
I believe you can download this paper freely from the internet.

A recent study specifically adressing the validity of the C2 power measurement, titled The mechanical rower: Construction, validity, and reliability of a test rig for wind braked rowing ergometers, by L. Mentz and coauthors, was published in the Journal of Biomechanics, 2020.
You can find the abstract on the internet, but not a free download.

[seneka21]

Dear Nomath, thank you very much for the extensive and very comprehensible response to my question.
My point was not about laboratory sesearch or experimental use of such a power meter-accelerator gauge.
That is even if concept models could be considered a supreme rowing tool, there are many people tha use comparable quality equipment e.g. Nordic, Kettler, Waterower etc.
Personaly I use a Waterrower Club S4 and occasionaly a 10y old Oartec Slider.
So my point was actually if there is any comercial product (similar to bicycle power meter) that actually converts almost any rowing machine to a
smart one, preferably measuring the power output at the handlebar level so that bypassing any unmeasurable energy loses.
Thanks again for your time.

[Nomath]

As far as I know, there are no simple add-on power meters. As Citroen pointed out, the PM is fully satisfactory for most users.

I like to add a few lines from Jim Flood's excellent book The Complete Guide to Indoor Rowing (Edition 2019, page 109) :
"At present, instrumented rowing machines [i.e. with handle force and position sensors] are not widely available and those that do exist have usually been built for research purposes in universities or as personal engineering projects. For many years, the Austrian rowing company WebaSport did offer a product which allowed direct measurement of handle force and position for Concept2 machines. This useful system sold at around 1200 Euros and came with software with simplified data analysis. Unfortunately it was discontinued in 2009."

[mitchel674]

Dear Nomath, thank you very much for the extensive and very comprehensible response to my question.
My point was not about laboratory sesearch or experimental use of such a power meter-accelerator gauge.
That is even if concept models could be considered a supreme rowing tool, there are many people tha use comparable quality equipment e.g. Nordic, Kettler, Waterower etc.
Personaly I use a Waterrower Club S4 and occasionaly a 10y old Oartec Slider.
So my point was actually if there is any comercial product (similar to bicycle power meter) that actually converts almost any rowing machine to a
smart one, preferably measuring the power output at the handlebar level so that bypassing any unmeasurable energy loses.
Thanks again for your time.

I am curious why you would want such a device. Is your hope to somehow standardize the results you achieve on these inconsistant rowers like your waterrower?

One of the nicest features about the Concept2 machines is that the machines accurately and reproducibly measure power production across all models. This enables rowers to compare times with others on a level playing field.

[seneka21]

Good or bad I m stuck with those non concept2 machines now. So no special reason besides I'd have to spend some additional hundred of bucks in order to upgrade to a concept2 solution. In any case it looks like that there is an empty fitness market space to be filled concerning some kind of an affordable "universal" rowing machine power meter (which to my opinion is not so technical demanding to be implemented).

[mitchel674]

Good or bad I m stuck with those non concept2 machines now. So no special reason besides I'd have to spend some additional hundred of bucks in order to upgrade to a concept2 solution. In any case it looks like that there is an empty fitness market space to be filled concerning some kind of an affordable "universal" rowing machine power meter (which to my opinion is not so technical demanding to be implemented).

I understand where you are coming from since you already own your waterrower. Can you please answer what you are trying to accomplish with your "power meter"? Isn't it enough for you to just get on you machine and row? It should be consistent from day to day as long as the water level is not changed.

Please also keep in mind that you are posting this question on a Concept2 owned forum. Most here are pretty pleased with what the Concept2 rowers offer given their relatively modest price.

[seneka21]

From one point of view I am trying to learn if there is any affordable way to convert a dumb machine to a smart one. Moreover I got surprised with the possibility that nobody has not already made such a "gadget ".
Concept2 is great and I understand your persistence with it. I had the oportunity to use it some times during previous visits to some gyms. The main reason I am posting here is that this seems to be one of the more populous and authoritative rowing forums therefore hopped to find an answer to my research. In any case sory for any inconvenience.

[mitchel674]

From one point of view I am trying to learn if there is any affordable way to convert a dumb machine to a smart one. Concept2 is great and I understand your persistence with it. I had the oportunity to use it some times during previous visits to some gyms. The main reason I am posting here is that this seems to be one of the more populous and authoritative rowing forums therefore hopped to find an answer to my research. In any case sory for any inconvenience.

Certainly no inconvenience!

I was more curious than put out. Good luck in your quest.

[Nomath]

You have to start it as a personal engineering project. If you look around, there are several affordable and robust force sensors than can be integrated between chain and handle. I am experimenting myself with a position sensor on the handle, because I believe it will provide interesting information about the stroke that is not available from the C2 performance monitor or ErgData.
The challenge is to combine those measurements, which are varying continuously, into a useful output in real time. Note that the power or pace displayed on the PM is an average value calculated for a full stroke.

[jackarabit]

Next week I’m starting an air passenger service with a single seat biplane. Propwash and wingwalk no problem but retrofitting the avionics is a headscratcher.

[Tsnor]

After a thorough though fruitless web search for a power meter in the form of handlebar, handlebar attachment or handlebar to chain linking device I decided to ask for help from the community. My point is to find a way to measure Athlete's power output at the level of handlebar so that bypassing any unmeasured energy losses in the system. Any ideas or information would be welcome. All the best to the community. 

If the goal is identical wattage output measurements to Concept2 you can't get there. C2 made too many decisions (such as ignoring work to pull the shock cord) that will not be translatable to a new device. C2 externally documents that to get true Calories from displayed cals throw in a 300 cal fudge factor then adjust by weight. For things like racing splits to be comparable they need to be done on the same type of machine.

Even bike cycle wattages (and Lifecycle for example gives flawless wattage according to US military studies) is not directly comparable to C2 rowing wattage. Athletes who use bike and row usually add 25W to C2 wattage to get their cycle output if they are equally skilled on both exercises.

p.s. I WISH I could pull some of the splits on C2 Mod D that I've done in the gym on water rowers (pre-covid). The water rowers I used gave 500M splits precisely displayed to the last second, but they were way easier than the same splits done on a C2 ... 30+ seconds difference over 2K.

BUY one C2 for calibrated rows. Let the members use that when they need to. Rest of time you can use your current machines. This will also keep your (club members?) from freaking out the first time they use a C2 or getting abuse when they compare splits online saying stuff like "everyone here is doing sub-7 minute 2Ks.").