POWER METERS: Crank, Hub or Pedal-based?

[Minion]

CONSIDER PREVIOUS POST, I HAVE A QUESTION:

 

Which crankset should I get to fit Quarg?

What criteria or considerations are there?

 

*I run SRAM Red on a Cannondale Super Six Hi Mod*

What are your criteria? Weight? Looks?

 

It's simplest to get one of the pre-built SRAM ones (you could wait for Red).

Buying just the spider requires a bit of admin. Quarq do not ship direct to SA at the moment. There are ways around this and people here have brought in other Quarqs, but is's not straightforward. If you want them to install the crank, you need to get the crank to them. Otherwise you need to install it yourself. I've done this when swapping cranks on my Quarq and it's not hard, but not everyone is technically inclined.

['Dale]

What are your criteria? Weight? Looks?

 

It's simplest to get one of the pre-built SRAM ones (you could wait for Red).

Buying just the spider requires a bit of admin. Quarq do not ship direct to SA at the moment. There are ways around this and people here have brought in other Quarqs, but is's not straightforward. If you want them to install the crank, you need to get the crank to them. Otherwise you need to install it yourself. I've done this when swapping cranks on my Quarq and it's not hard, but not everyone is technically inclined.

 

The current crankset is good, not ideal, to continue with until I wait for the new Red, Edam & Zac.A.

My ol' Red FD is also so moody, as you might know, so the new Red FD will prob also be added.

 

Now to fill the piggy bank a bit more....

['Dale]

What are your criteria? Weight? Looks?

 

Both new Red crankset and Hollowgram is good looking.

Hollowgram might be lighter, me think.

 

Let me research.

 

As you suggest, it would be more convenient to purchase the Red crankset with Quarg integrated already.

[LOOK695]

Question to those who know: what is the meaning of "normalized power"?

[Minion]

Question to those who know: what is the meaning of "normalized power"?

http://home.training...ress-score.aspx

 

It's a smoothing algorithm for power to account for the variability of power readings through a ride. It emphasises higher power efforts, as opposed to average power that gives equal weighting to high and low power. Most implementations of NP require you to be using one second recording.

 

The algorithm goes something like:

1.) Take a 30s moving average of power throughout the ride (P_30)

2.) Raise the values obtained in 1.) to the fourth power (P_30^4)

3.) Take an average of all the values calculated in 2.)

4.) Take the fourth root of the value from 3.) to get normalised power.

 

For a ride, such as a time trial, where the effort is constant, normalised power = average power. For rides with a highly variable power output e.g. sprint intervals, NP will be much greater than AP.

Edited April 7, 2012 by Edam

[LOOK695]

http://home.training...ress-score.aspx

 

It's a smoothing algorithm for power to account for the variability of power readings through a ride. It emphasises higher power efforts, as opposed to average power that gives equal weighting to high and low power. Most implementations of NP require you to be using one second recording.

 

The algorithm goes something like:

1.) Take a 30s moving average of power throughout the ride (P_30)

2.) Raise the values obtained in 1.) to the fourth power (P_30^4)

3.) Take an average of all the values calculated in 2.)

4.) Take the fourth root of the value from 3.) to get normalised power.

 

For a ride, such as a time trial, where the effort is constant, normalised power = average power. For rides with a highly variable power output e.g. sprint intervals, NP will be much greater than AP.

Thanks

[DangerDave]

 

Do they realise that Quarq is a SRAM product and comes in through, and is supported by, the SRAM supply chain?

 

Edit: The support I've received to my queries both directly from Quarq in the US and from CCS locally has been good. If something goes wrong with the electronics, it would probably have to be sent overseas for repair. Likewise for SRM, P2M and possibly Powertap (I know they can service the hub mechanicals, but I'm not sure how much electronic repair they can do).

 

Should the Power Tap system go wrong and bicycle power are unable to re-calibrate the system a new torque tube can be installed, they can do it while you wait should you make an appointment therefore making power tap not only the cheapest option but also the option with the best local support * applies to units that are bought through bicycle power, "grey" imports will incour extra costs.

 

Therefore NO need to send the unit back to the USA, loan wheels are also available should the fix take longer than 1 day

[Minion]

Should the Power Tap system go wrong and bicycle power are unable to re-calibrate the system a new torque tube can be installed, they can do it while you wait should you make an appointment therefore making power tap not only the cheapest option but also the option with the best local support * applies to units that are bought through bicycle power, "grey" imports will incour extra costs.

 

Therefore NO need to send the unit back to the USA, loan wheels are also available should the fix take longer than 1 day

This is good to hear.

['Dale]

I am letting this option go - Garmin Vector.

 

From velonews.com

 

After testing our latest advanced prototypes of the Vector system, we are still not satisfied with the results. As you can imagine, Vector is a complex, precision measurement instrument and as of yet, we are unable to ensure that this device will meet the expectations of the cycling community. Presently, we cannot estimate a delivery date but we do not expect the product to be ready in the summer of 2012, as previously targeted. We understand that this is a highly anticipated product within the cycling community, but Garmin’s commitment to quality necessitates this additional delay. We will update our customers when we have additional information to share. Thank you for your understanding.

[capeofstorms]

http://home.training...ress-score.aspx

 

It's a smoothing algorithm for power to account for the variability of power readings through a ride. It emphasises higher power efforts, as opposed to average power that gives equal weighting to high and low power. Most implementations of NP require you to be using one second recording.

 

The algorithm goes something like:

1.) Take a 30s moving average of power throughout the ride (P_30)

2.) Raise the values obtained in 1.) to the fourth power (P_30^4)

3.) Take an average of all the values calculated in 2.)

4.) Take the fourth root of the value from 3.) to get normalised power.

 

For a ride, such as a time trial, where the effort is constant, normalised power = average power. For rides with a highly variable power output e.g. sprint intervals, NP will be much greater than AP.

 

 

Does the Garmin edge 500 head unit provide this smoothing?

Edited April 12, 2012 by capeofstorms

[capeofstorms]

Has anyone done a cost/benefit analysis between quarq and powertap (lets say PRO). How much cheaper is the powertap??

[Bike Mob]

For those of you still deciding...

 

I have a Sram Red Quarq Cinco 172.5 BB30 39/53 that I will be selling in the next week or two...*Ahem Puncheur this is perfect for you*

 

Only 6 months old, torqued, and calibrated. Perfectly operational and rings are in very good condition.

Edited April 12, 2012 by Tarmac's Revenge

[DangerDave]

and for all those wanting a SRM: https://www.bikehub.co.za/index.php?app=hubmarket&do=view_item&item_id=13367

[Spinnekop]

For those of you still deciding...

 

I have a Sram Red Quarq Cinco 172.5 BB30 39/53 that I will be selling in the next week or two...*Ahem Puncheur this is perfect for you*

 

Only 6 months old, torqued, and calibrated. Perfectly operational and rings are in very good condition.

 

ooooooooooooooooooooo

Same as mine....perfect!!! Especially on the 'Dale......

[kosmonooit]

I am letting this option go - Garmin Vector.

 

From velonews.com

 

After testing our latest advanced prototypes of the Vector system, we are still not satisfied with the results. As you can imagine, Vector is a complex, precision measurement instrument and as of yet, we are unable to ensure that this device will meet the expectations of the cycling community. Presently, we cannot estimate a delivery date but we do not expect the product to be ready in the summer of 2012, as previously targeted. We understand that this is a highly anticipated product within the cycling community, but Garmin’s commitment to quality necessitates this additional delay. We will update our customers when we have additional information to share. Thank you for your understanding.

 

 

Yes well better they sort it out than release something that doesn't work. What sound like an elegant and simple solution seems to have some complications!

Edited April 12, 2012 by kosmonooit

[BigGuy]

Yes well better they sort it out than release something that doesn't work. What sound like an elegant and simple solution seems to have some complications!

I wonder if there is not some legal issue regarding pedal platform to blame here?