Stages Power Meter

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Re: Stages Power Meter

Postby dale79 » Fri Aug 09, 2013 10:42 am

ok mate, we get the point that you don't like the cheap meters that are going to cut your sales on the meters that you sell due to these being less than half the price etc, I understand that, but when the peak power readings are all with in a few % of each other on the market you can try and spin and baffle people to your hearts content but at the end of the day people buying these meters like my self don't really care about left and right balance etc they just want something that gives them a approx power output which it has been shown that these do it very well.
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by BNA » Fri Aug 09, 2013 11:11 am

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Re: Stages Power Meter

Postby trek52 » Fri Aug 09, 2013 11:11 am

if someone did have a large power difference between legs that was identified correctly, how would you go about fixing the issue ?
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Re: Stages Power Meter

Postby Xplora » Fri Aug 09, 2013 11:17 am

Alex Simmons/RST wrote:
dale79 wrote:
Alex Simmons/RST wrote:
But what is more telling is whether the information is of any substantive value.


exactly.. for 99% of riders the info given is perfectly fine, for what I want the stages will be perfectly fine.

What you need it for may not represent 99% of riders, I think that's a pretty big assumption.

And this, gentlemen, is where the rubber hits the road and the proof shall be in the pudding. We don't need to speculate on this question: the market will answer it for us in due time. The move on the G3 by Powertap implies that there is more going on than we realise. The Riken PM is quite cheap now too. Stages has at the least pushed change in the market. I suspect that Alex is correct about the current PM users, but Dale and I are right about the willing riders who don't have one yet ;)
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Re: Stages Power Meter

Postby Xplora » Fri Aug 09, 2013 11:22 am

trek52 wrote:if someone did have a large power difference between legs that was identified correctly, how would you go about fixing the issue ?

Get a fit done, remedial work on and off bike as needed. But only as needed because of injury history. Alex rides without a physical leg and I am sure he actually would wet himself laughing at me trying to catch him on a track bike. I was balanced by Steve Hogg and I am not entirely convinced it was the magic bullet.
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Re: Stages Power Meter

Postby kb » Fri Aug 09, 2013 2:35 pm

I though Alex's point wasn't that left / right imbalance needs fixing necessarily, but it's the numbers produced by assuming there isn't any that need fixing.
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Re: Stages Power Meter

Postby toolonglegs » Fri Aug 09, 2013 3:26 pm

I am not in the 99% yet... due to a few reasons, one of which is I am pretty sure I have big imbalances, especially when fatiguing.
Also be interested to see how they go over time, obviously water proofing is an issue. No good for me as I ride in the rain and cold constantly ... just ask my garmin 705 that died yesterday :| .
Also wondering how user verifiable stages are, especially after a year or so of use when the cranks start to get a bit of fatigue / flex in them?.

What I do like about them is that whether they prove to be any good or not, along with the other new comers on the market ... they will push the prices down of the other contenders. Powertaps $500 drop says something about inflated prices!.
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Re: Stages Power Meter

Postby Xplora » Fri Aug 09, 2013 3:30 pm

kb wrote:I though Alex's point wasn't that left / right imbalance needs fixing necessarily, but it's the numbers produced by assuming there isn't any that need fixing.

Now, this logic is precisely why I hold the view that I do. 100%.

The saying goes "if it ain't broke, don't fix it". Stages is a PM brought to the market at a price point. It isn't a SRM worth 3 times the cost. It is miles more flexible than much of the competition. If L/R balance isn't an issue for your analysis, then ignoring the L/R balance isn't an issue for your measurement. If you really have a burning desire to know, you can get something else.

You aren't getting proper L/R splits from most PMs. Looks like Vector will be... at around double the cost. And you have to use the Look cleat. yay. Considering that Garmin COULD have brought a PM to market with just one pedal, and chose not to (guarantee that you will see a single pedal version similar to the Stages one leg solution going for 400-500 bucks in 2 years, watch this space) thus deliberately raising the cost to recover investment at the expense of early adopters, there is concern around the real NEED for the split.

Anyways, the issue is that you will get distortions in the data as you might favour a leg as you tire because you aren't getting both legs. Now... while I agree that this could potentially be an issue, where is the NEED for the data? What are you going to do if your natural tendency is to protect a leg as you wear down over a ride?

If you are Alex and training world record holders, this is important stuff. But if you aren't going for the Hour Record, perhaps the SRM level equipment isn't necessary. Maybe you'd be better off spending the extra 1000 bucks on coaching, or a different rear wheel to TT with? It's an ENORMOUS outlay for what is likely to be severely diminishing returns. Given all the cheaper PMs top out at 1.5% accuracy, you will needing "R/L leg" power readings maybe 10W difference consistently to even show up outside the error, plus you are then making an assumption that your right leg is failing while your left leg powers on (or the reverse) meaning your overall power doesn't reflect the Stages data. We won't mind that you won't have much ability to address this issue or diagnose it without a proper two sided PM ala Vector.

I really need to stress this comment at this point (and it's why I'm OK with the PowerCal). People have trained for DECADES without power. Tell a runner they aren't getting useful data from their HRM strap. Any information that is accurate, and consistently repeatable for the rider in question, is useful. Once you're A grade and nudging NRS level and your coach can't work out why you aren't able to take the extra step, you might need to move beyond the Stages PM. How many stories have we heard about single side failure in riders? We would already know intuitively that the power from each side was out by more than 2%. The need would have been addressed by now (we've had PMs for a while) but it doesn't seem to have been an issue. We would certainly have heard about riders saying "I just can't work out how come I'm so weak, yet my power readings are fine"... we would have heard about coaches complaining about L/R imbalance a lot more... scepticism from wise heads like Alex is good, because no one is helped by hype, but sometimes we need to accept that painting your house is not the same as the Sistine Chapel and you can get away with less than Michelangelo to do the painting.
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Re: Stages Power Meter

Postby toolonglegs » Fri Aug 09, 2013 3:55 pm

Alex isn't saying L/R splits are important... just that total power is. Something that Stages doesn't give you. Right or wrong, that is a fact ... it just works on the assumption that all things are equal.
Whether that is good enough for you will decide whether you buy a stages power meter ... or a powertap etc.
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Re: Stages Power Meter

Postby Alex Simmons/RST » Fri Aug 09, 2013 4:02 pm

dale79 wrote:ok mate, we get the point that you don't like the cheap meters that are going to cut your sales on the meters that you sell due to these being less than half the price etc, I understand that, but when the peak power readings are all with in a few % of each other on the market you can try and spin and baffle people to your hearts content but at the end of the day people buying these meters like my self don't really care about left and right balance etc they just want something that gives them a approx power output which it has been shown that these do it very well.


I think you misunderstand what I'm saying.

Bring on lots of quality choice I say. Just be well informed about what you are buying, and don't assume that what's important for you is important for others.

Also, I agree - IMO L-R balance (when you measure total power) is a big fat red herring.
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Re: Stages Power Meter

Postby Alex Simmons/RST » Fri Aug 09, 2013 4:06 pm

trek52 wrote:if someone did have a large power difference between legs that was identified correctly, how would you go about fixing the issue ?

The first question is whether you need be concerned about it first. Asymmetry is normal.

There are some fit issues that may be in play but that doesn't require a L-R balance to identify/address those.
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Re: Stages Power Meter

Postby Alex Simmons/RST » Fri Aug 09, 2013 4:07 pm

Xplora wrote:
trek52 wrote:if someone did have a large power difference between legs that was identified correctly, how would you go about fixing the issue ?

Get a fit done, remedial work on and off bike as needed. But only as needed because of injury history. Alex rides without a physical leg and I am sure he actually would wet himself laughing at me trying to catch him on a track bike. I was balanced by Steve Hogg and I am not entirely convinced it was the magic bullet.

You'd catch me in a flash ATM, I'm a fat slug who is not riding at present. Doing far more volunteer race support work than riding now days.
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Re: Stages Power Meter

Postby Alex Simmons/RST » Fri Aug 09, 2013 4:20 pm

Xplora wrote:
kb wrote:I though Alex's point wasn't that left / right imbalance needs fixing necessarily, but it's the numbers produced by assuming there isn't any that need fixing.

Now, this logic is precisely why I hold the view that I do. 100%.

The saying goes "if it ain't broke, don't fix it". Stages is a PM brought to the market at a price point. It isn't a SRM worth 3 times the cost. It is miles more flexible than much of the competition. If L/R balance isn't an issue for your analysis, then ignoring the L/R balance isn't an issue for your measurement. If you really have a burning desire to know, you can get something else.

You aren't getting proper L/R splits from most PMs. Looks like Vector will be... at around double the cost. And you have to use the Look cleat. yay. Considering that Garmin COULD have brought a PM to market with just one pedal, and chose not to (guarantee that you will see a single pedal version similar to the Stages one leg solution going for 400-500 bucks in 2 years, watch this space) thus deliberately raising the cost to recover investment at the expense of early adopters, there is concern around the real NEED for the split.

Anyways, the issue is that you will get distortions in the data as you might favour a leg as you tire because you aren't getting both legs. Now... while I agree that this could potentially be an issue, where is the NEED for the data? What are you going to do if your natural tendency is to protect a leg as you wear down over a ride?

If you are Alex and training world record holders, this is important stuff. But if you aren't going for the Hour Record, perhaps the SRM level equipment isn't necessary. Maybe you'd be better off spending the extra 1000 bucks on coaching, or a different rear wheel to TT with? It's an ENORMOUS outlay for what is likely to be severely diminishing returns. Given all the cheaper PMs top out at 1.5% accuracy, you will needing "R/L leg" power readings maybe 10W difference consistently to even show up outside the error, plus you are then making an assumption that your right leg is failing while your left leg powers on (or the reverse) meaning your overall power doesn't reflect the Stages data. We won't mind that you won't have much ability to address this issue or diagnose it without a proper two sided PM ala Vector.

I really need to stress this comment at this point (and it's why I'm OK with the PowerCal). People have trained for DECADES without power. Tell a runner they aren't getting useful data from their HRM strap. Any information that is accurate, and consistently repeatable for the rider in question, is useful. Once you're A grade and nudging NRS level and your coach can't work out why you aren't able to take the extra step, you might need to move beyond the Stages PM. How many stories have we heard about single side failure in riders? We would already know intuitively that the power from each side was out by more than 2%. The need would have been addressed by now (we've had PMs for a while) but it doesn't seem to have been an issue. We would certainly have heard about riders saying "I just can't work out how come I'm so weak, yet my power readings are fine"... we would have heard about coaches complaining about L/R imbalance a lot more... scepticism from wise heads like Alex is good, because no one is helped by hype, but sometimes we need to accept that painting your house is not the same as the Sistine Chapel and you can get away with less than Michelangelo to do the painting.


I think you will find I have consistently made the point that once one realises what their goals are, then the training aids which are able to satsfy the data demand to support that goal becomes apparent.

Stages is likely a great option for some because the quality of the data required for general training isn't overly demanding, but it isn't suitable for other applications.

Keep in mind that there is still a lot of ignorance about the ways the data can be used for performance improvement. Indeed I am soon to unveil in Australia some leading edge technologies which make use of such data, and the quality and reliability of that data is paramount to being able to take advantage of such things.

I do not make an assumption about what people's individual needs are.
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Re: Stages Power Meter

Postby Alex Simmons/RST » Fri Aug 09, 2013 4:24 pm

toolonglegs wrote:Alex isn't saying L/R splits are important... just that total power is. Something that Stages doesn't give you. Right or wrong, that is a fact ... it just works on the assumption that all things are equal.
Whether that is good enough for you will decide whether you buy a stages power meter ... or a powertap etc.

Exactly.
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Re: Stages Power Meter

Postby kb » Sat Aug 10, 2013 8:24 am

Xplora wrote:Anyways, the issue is that you will get distortions in the data as you might favour a leg as you tire because you aren't getting both legs. Now... while I agree that this could potentially be an issue, where is the NEED for the data? What are you going to do if your natural tendency is to protect a leg as you wear down over a ride?

Well any power meter for me would be a bit of a luxury. But I love the idea at least of being able to do something like http://bikeblather.blogspot.com.au/2013 ... d.html?m=1
Fully understand that there are uses in between perceived effort and precise PM.
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Re: Stages Power Meter

Postby Alex Simmons/RST » Sat Aug 10, 2013 11:29 am

kb wrote:Well any power meter for me would be a bit of a luxury. But I love the idea at least of being able to do something like http://bikeblather.blogspot.com.au/2013 ... d.html?m=1
Fully understand that there are uses in between perceived effort and precise PM.

The data from a Stages power meter would be inadequate for that application.
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Re: Stages Power Meter

Postby dale79 » Sun Aug 11, 2013 3:23 pm

here is one that will ship to AUS, 175mm dura ace 7900.. little over priced but bargin away,

http://www.ebay.com.au/itm/Stages-Power ... 35ca813352
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Re: Stages Power Meter

Postby winstonw » Sun Aug 11, 2013 7:00 pm

does anyone want to spell out what a non elite, non NRS cyclist is going to use a power meter for, then explain why a Stages is inadequate for the purpose?

I'll start:
At some stage I will buy and train with a power meter. I'll use it to
1. establish a power profile, then tweak my training to optimize the profile.
2. facilitate race performance by avoiding blowing up.

At my age and with my musculoskeletal history, I know the difference I can make to L/R power variation is minimal.
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Re: Stages Power Meter

Postby dale79 » Sun Aug 11, 2013 8:24 pm

winstonw wrote:does anyone want to spell out what a non elite, non NRS cyclist is going to use a power meter for, then explain why a Stages is inadequate for the purpose?

I'll start:
At some stage I will buy and train with a power meter. I'll use it to
1. establish a power profile, then tweak my training to optimize the profile.
2. facilitate race performance by avoiding blowing up.

At my age and with my musculoskeletal history, I know the difference I can make to L/R power variation is minimal.


they are not Inadequate.. you just have to read between the salesmen of other brands and work out what is true and what is being spun by people with ulterior motives etc..

you will establish a power profile and be able to train no problems at all, anything you can do with a powertap you can do with a stages.. despite what some people will say.. go read DCrainmakers review, the power outputs coming from the 4 meters on his bike are with in a few % of each other which unless you are a elite pro will be good enough.. remember all you need is consistent readings, doesn't really matter if you are reading a couple of % high or low..
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Re: Stages Power Meter

Postby Xplora » Sun Aug 11, 2013 9:02 pm

That's something that annoys me. All the PMs in Rays reviews give different readings from all of them. Internal consistency is king.
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Re: Stages Power Meter

Postby takai » Mon Aug 12, 2013 9:41 am

Personally im turned off the Stages by the left arm only reading, and its only to do with a previous injury. My left knee has been pretty heavily damaged.

That said I am using one of the cheap CycleOps HRM Power meters after my Garmin HRM died. While im fully aware of the limitations of it, the data provided is within about 5% of a mates PowertapG3 that i borrow sometimes, and it gives me good enough tracking information for what i want. The biggest bit is that its relatively consistent across training. Bigger again is that because of the power meter data, the ANT+ actually transmits at a higher frequency than the standard Garmin HRM, and gives more accurate HRM data.

It is horses for courses though.
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Re: Stages Power Meter

Postby dale79 » Mon Aug 12, 2013 11:06 am

takai wrote:Personally im turned off the Stages by the left arm only reading, and its only to do with a previous injury. My left knee has been pretty heavily damaged.

.


So how much weaker is your left leg? Have you measured it or are you just guessing?
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Re: Stages Power Meter

Postby takai » Mon Aug 12, 2013 11:22 am

dale79 wrote:
takai wrote:Personally im turned off the Stages by the left arm only reading, and its only to do with a previous injury. My left knee has been pretty heavily damaged.

.


So how much weaker is your left leg? Have you measured it or are you just guessing?


Not so much weaker, but rather the joint more than occasionally plays up and i spend a km or so actively NOT putting any load on my left leg and only pedalling with my right leg, and at times i spend 500+m with my left leg unclipped and straightened while still pedalling with the right. Apparently it looks hilarious :shock:

Its one of two reasons im not actually on the road bike at the moment.
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Re: Stages Power Meter

Postby dale79 » Mon Aug 12, 2013 11:24 am

In that case any power meter will only be half accurate while your not putting any power out with your left leg
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Re: Stages Power Meter

Postby takai » Mon Aug 12, 2013 11:26 am

Yeah, which is fair enough, only i tend to up the load on my right leg to compensate.

For now though the CycleOps gives enough data to measure changes, so its enough for what i want. Maybe ill nick stockys wheel and go for a ride at some point, see if he can show me how to use power data better.
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Re: Stages Power Meter

Postby dalai47 » Mon Aug 12, 2013 12:08 pm

dale79 wrote:In that case any power meter will only be half accurate while your not putting any power out with your left leg


How half accurate? If the PM measures both legs, by pedaling with one it will display the power generated by that one leg.
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