Dc Rainmaker Comment

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ldmitruk
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Dc Rainmaker Comment

Post by ldmitruk »

Hi,

DC Rainmaker has just published his 2014 Power Meter Buyer's Guide. According to him iBike doesn't update very often. About the only response I can think of is he doesn't follow what's happening with iBike at all. Pretty amazing he has the time to test just about anything else that comes on the market but not the iBike.
Pete
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Re: Dc Rainmaker Comment

Post by Pete »

http://www.dcrainmaker.com/2015/08/head ... rbike.html
I’d love to see iBike come out with their long rumored standalone wind/power sensor (which would actually be cool and I think could gain respectable market share if they don’t hose up marketing/PR). But, I’m not going to waste time reviewing the Newton, as I just don’t get it.
Pete
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Re: Dc Rainmaker Comment

Post by Pete »

Pete wrote:http://www.dcrainmaker.com/2015/08/head ... rbike.html
I’d love to see iBike come out with their long rumored standalone wind/power sensor (which would actually be cool and I think could gain respectable market share if they don’t hose up marketing/PR). But, I’m not going to waste time reviewing the Newton, as I just don’t get it.
If they come out with a product that isn’t just another twin of their existing head unit – I’d be happy to look at it. If they come out with a standalone product (no head unit) that transmits power over ANT+/BLE (and done), I’d be thrilled about it. John has my e-mail and is welcome to setup a meeting – if such a product exists and can be demonstrated I’m in the Eurobike area by mid-day Monday with my bike and would ensure a post on it for Eurobike show open.
Velocomp
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Re: Dc Rainmaker Comment

Post by Velocomp »

I have sent an email to Ray. Waiting for a response...
John Hamann
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Re: Dc Rainmaker Comment

Post by Velocomp »

OK, I made contact with Ray. Here is his review of the new PowerPod power meter:

http://www.dcrainmaker.com/2015/08/firs ... power.html
John Hamann
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Re: Dc Rainmaker Comment

Post by EHB »

Pretty much as you'd expect I think. I note the comment about being able to transfer other metrics, outside ANT+, and your enthusiasm. That sounds like a really key point to me, although potentially I am biased as I have both a DFPM and a Newton+. Apart from Powerstroke, the main thing I use it for is live air resistance.

Getting a new protocol sanctioned by ANT would probably be a nightmare, but I wonder if you developed an open and clearly documented ANT (not +) transmission whether makers of head units would incorporate it… I haven't looked into it but Garmin allow a degree of programming of devices with installation of Apps - you could definitely write an App and you wouldn't need to get cooperation with other manufacturers. I believe other manufacturers of novel devices are already doing it, such as oxygen sensors. I have a Suunto watch and, although it has Apps, it is too much of a walled garden for it to be possible, their support are rubbish and they aren't keen to help.

He also mentioned the potential problems with varying rolling resistances. I imagine different surfaces create different spectrums of noise on the movement sensor. Maybe you already do it, but it shouldn't be that hard to get it to vary the CRR a little up or down depending on the noise - which would then counteract that point. Not that I think it is that relevant anyway, I've found the hard bit of cobbles isn't the absolute power output, but the sudden muscle shortening or increases in resistance that are really tiring. A DFPM can't give you that. Maybe that is another opportunity for iBike to put out another unique metric…
Pete
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Re: Dc Rainmaker Comment

Post by Pete »

EHB wrote:He also mentioned the potential problems with varying rolling resistances. I imagine different surfaces create different spectrums of noise on the movement sensor. Maybe you already do it, but it shouldn't be that hard to get it to vary the CRR a little up or down depending on the noise - which would then counteract that point.
Perhaps something along the lines of the coast down and "Cda" tests? eg change surface...coast for 10 secs...CRR updates and away you go.

John, there seems some confusion (in the DCR comments) as to whether you need to pair the Pod to speed or cadence or both (and/or get speed via GPS)

PS congrats on the product and good luck!
Pete
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Re: Dc Rainmaker Comment

Post by Pete »

Is there an ANT+ protocol for a 2nd power meter?
Zoltan
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Re: Dc Rainmaker Comment

Post by Zoltan »

Velocomp wrote:OK, I made contact with Ray. Here is his review of the new PowerPod power meter:

http://www.dcrainmaker.com/2015/08/firs ... power.html
It's good to see. I own the nickname "Tisztul_A_Visztula" and was the one who started to provoke Ray on 19th August with the missing Newton review.
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Re: Dc Rainmaker Comment

Post by Velocomp »

Zoltan wrote:
Velocomp wrote:OK, I made contact with Ray. Here is his review of the new PowerPod power meter:

http://www.dcrainmaker.com/2015/08/firs ... power.html
It's good to see. I own the nickname "Tisztul_A_Visztula" and was the one who started to provoke Ray on 19th August with the missing Newton review.
Thank you for your prodding. Ray is a good guy and did a very nice, and fair, job with his PowerPod review.
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Re: Dc Rainmaker Comment

Post by EHB »

Pete wrote:Perhaps something along the lines of the coast down and "Cda" tests? eg change surface...coast for 10 secs...CRR updates and away you go.

I'm not sure it needs a full 10s. How often do you not pedal for 10S, particularly if you hit something rough like cobbles? On gravel I think you' dome to a stop. There must be quite a lot of noise from the movement sensor. Low frequency stuff might relate to rocking of the bike and lack of smooth pedalling. High frequency noise I don't imagine would be as easy to create. If you added a high pass filter I imagine different types of terrain would have a typical spectral profile…you could even flag it on Isaac; I imagine fun could be have designing it into the graph.

Retrospectively, from Powerstroke data because of its increased frequency, I think you also be able to get some interesting stuff that more closely relates to muscle fatigue than Normalised Power, which I think is a bit of a rubbish oversimplification.
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Russ
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Re: Dc Rainmaker Comment

Post by Russ »

EHB spoke of High frequency noise.

I have thought of this myself as something the iBike firmware could use to distinguish the surface roughness and adjust Crr on the fly somewhat. Even if it was a bit of a swag using 'typical' offsets it would improve accuracy.

If iBike is using any signal processing in the unit, a low pass filter normally does not necessarily require the high frequency data to be thrown away, does it? It should be possible to continue the present use of the lower frequency data as is and add the new functions using what was probably thrown away.

For that matter, if they get the Crr adjustment routine nailed, then the CdA could start to be made dynamic too!

Just saying,
Russ
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Re: Dc Rainmaker Comment

Post by nsidirop »

Just for my understanding, is there a difference in the algorithms calculating power between Newton and PowerPod ?
EHB
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Re: Dc Rainmaker Comment

Post by EHB »

Russ, CdA is dynamic if you have a DFPM. It isn't displayed constantly, but it is cycled in. Only to two significant figures. I'd like to see it to three figures but I guess it is too noisy.

My understanding of filters is that data doesn't have to be thrown away, for example speaker cabinets filter frequencies to the correct speaker size. I have no idea how their circuit is designed, but if I had to guess I would think there was some sort of filter on the analogue signal from the oscillometer, but wouldn't be suprised if it was designed into the chip itself and the data was the unsavably lost.
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Russ
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Re: Dc Rainmaker Comment

Post by Russ »

EHB said "Russ, CdA is dynamic"

This is true for the CdA display functionality. I am referring to future adaptive CdA algorithms that I can envision being developed. Just dreaming the future :-)

Russ
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Re: Dc Rainmaker Comment

Post by KenS »

EHB wrote:My understanding of filters is that data doesn't have to be thrown away, for example speaker cabinets filter frequencies to the correct speaker size. I have no idea how their circuit is designed, but if I had to guess I would think there was some sort of filter on the analogue signal from the oscillometer, but wouldn't be suprised if it was designed into the chip itself and the data was the unsavably lost.
More likely to be a digital filter coded into the firmware.
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Re: Dc Rainmaker Comment

Post by EHB »

Ray has uploaded a YouTube video looking at the power pod. Looks quite good to me.

http://youtu.be/88bZuBF-ZCw
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Re: Dc Rainmaker Comment

Post by EHB »

Ken, if you are right and it is firmware that gives them greater scope to improve it.

Most PM transmit at 1 second intervals only. I think it gives Velo comp the opportunity to produce a better metric than power.

As regards the Power pod, I guess the question is whether they will utilise the ability to write Apps and use private ANT in new garmins.
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Re: Dc Rainmaker Comment

Post by Velocomp »

EHB wrote:Ray has uploaded a YouTube video looking at the power pod. Looks quite good to me.

http://youtu.be/88bZuBF-ZCw
It's a very good and fair review. The reason PP "lags" behind his DFPM is because we designed it that way, so that long intervals would be smooth but sprints would respond instantly (Dynamic Power Smoothing--standard in the Newton).

Also, 1 second power peak is a meaningless number, in our view.

We've emailed Ray and look forward to his more detailed comments.
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Re: Dc Rainmaker Comment

Post by Glenn Belt »

The DC Rainmaker podcast was talking about Powerpod today - the basic gist was that 95% of the time it works everytime. Unless it's on cobbles or off-road.

Seems like it'll be a good review when it's published in the next week or so.
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