# Stages or Power Tap Power Meter?



## knezz (Aug 10, 2013)

Greetings,

Here we go again!!!!</SPAN>

I know this was discussed a while ago but most of the conversation was before Stages created a firmware update. Stages was not an option until I read that the firmware update corrected most of it’s issues.
</SPAN>
I can get the G3 Wheel Set for $800.00 (but will need a cassette, tires, tubes = another $150.00) so total will be around $950.00 and the Stages is $800.00.
</SPAN>
Does one meter give more and/or better data than the other?</SPAN>
I want to be able to save my rides and note the terrain to find out how I’m doing on inclines by the degree of the inclines and length. I want to be able to what my progress in output. I’ve been riding for a little more than 3 weeks with only about 300 miles under my belt. I feel the Power Meter is essential in tracking my progress as well of showing what changes in techniques work for me.</SPAN>

My goals are to lose some weight, be able to keep up or eventually issue some pain on group rides and next season do a few centuries. </SPAN>

I have one road bike and don’t expect to get a 2[SUP]nd[/SUP] bike for some time. I won’t be riding in too much mud and dirt if I can help it but I want something that could stand up to the elements. Speaking of elements, I read that Stages adjust for temperature changes and Powertap doesn’t?</SPAN>

I want something that works well and reliable. I understand that Stages takes on leg and doubles the readings. Some say that’s a show stopper and others say is minor? How does Powertap distinguish between the two sides?</SPAN>

Regards,


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## arai_speed (Aug 19, 2003)

Stages Power Meter In-Depth Review Update | DC Rainmaker


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## knezz (Aug 10, 2013)

arai_speed said:


> Stages Power Meter In-Depth Review Update | DC Rainmaker


I did read that and it is very informative. When I read the orginal report along with others take on Stages - Powertap was going to be the choice because of it's price drop. After the updated review - I am back on the fence between the two.


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## drussell (Aug 6, 2010)

knezz said:


> Greetings,
> 
> Here we go again!!!!</SPAN>
> 
> ...


Far be it for anyone here to tell anyone else how to spend their money, so this bit will be brief: for your stated goals, you don't need a power meter. _At all_. A HRM and a lot more (consistent) riding will get you there. And the HRM is optional, but will give you something to satisfy your data craving.

That said, you know what the differences and limitations of both systems are already from reading the review. You don't need a new cassette, tires or tubes for the G3 - just take them off your current wheels. So, if it comes down to the same price, I'd probably go with the PT just for the amount of time they've been around the block and overall robustness. PT doesn't do left/right power - it measures power at the rear hub, downstream of the pedals. 

Ultimately, both systems will do whatever you want at your current level of riding - neither one will be the rate-determining step in your improvement.


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## arai_speed (Aug 19, 2003)

Any descent GPS system like Garmin Edge series (200,500,510, 800,810) will save your rides and you can upload them to multiple sites for review. Strava.com is a great tool for showing you how you are performing on a particular "segment" and will give you the grade of the segment as well as show track your efforts and will compare your efforts against others.

To get your fix on more data, a cadence meter and a HR monitor will provide plenty of information.

All of the above can be had for far far less than a Power Meter.


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## Wookiebiker (Sep 5, 2005)

I'm not going to try and talk you out of a powermenter just because I think they are excellent tools to improve performance and if you like cycling they can add a whole other dimension, especially if you are a numbers/tech geek.

I have two powertaps and a stages power meter (on my commuter bike).

Both are consistent when it comes to data recording and work well enough for all intents and purposes. The Powertap tends to record about 2% or so higher with it's numbers than the Stages.

I have found the Stages "Zero's" quickly and consistently with my Garmin 500 however the Powertap sometimes takes a fair amount of time or doesn't zero at all (or I just get tired of waiting for it to zero).

The other benefit of the Stages is you can run any rear wheel you want with it. The Powertap you are stuck with what ever spoke/rim combination you purchase with the hub ... or switch out to later.

I won't say either is better than the other ... just that they both work well and do what they advertise.


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## stanseven (Nov 9, 2011)

Wookiebiker gives excellent advice. I won't give my opinion on which is better because they both are good but for different reasons. A powermeter can be very motivational and really helpful for training and improvement, especially if are a data driven person. But it's important to know who to use it so either buy a book or do lots of online research to develop a good training approach. But one warning is a lot of people tire of the data slave a powermeter makes them become.


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## uncrx2003 (Jul 17, 2010)

I bought the powertap from excelsports that is laced to HED C2 rim. It has been excellent so far. Customer service is amazing too. From my short experience, it's pretty reliable other than the sending unit on the wheel was bad from the start. They sent me a new one no question asked. I don't race and have never like deep wheels so the wheel thing doesn't bother me one bit. I'm going to convert both of my bikes to 11 speeds so I can interchange the wheel between the bikes. It did come down to stages vs PT for me too. I think either one will work just fine. Like others have said, PT has been around for while.


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## ukbloke (Sep 1, 2007)

With Stages you always have the left/right uncertainty (if that matters to you). With PowerTap you have the one wheel limitation. Pick your poison. I went with PowerTap, and it has indeed been quite effective at stopping me from buying new wheels. This has actually turned out to be a plus.


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## Newnan3 (Jul 8, 2011)

ukbloke said:


> With Stages you always have the left/right uncertainty (if that matters to you). With PowerTap you have the one wheel limitation. Pick your poison. I went with PowerTap, and it has indeed been quite effective at stopping me from buying new wheels. This has actually turned out to be a plus.


Ive had the same experience as far as preventing me from buying another wheelset. Its actually a good thing....However, i would like a set of lightweight 24mm carbon tubulars for racing. The problem is I would want the power data from the race to see how im looking when i eventually get dropped. 

In this case the stages would be better for me....Maybe i could just run a carbon tubular on the front but who does that?!


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## Wookiebiker (Sep 5, 2005)

Newnan3 said:


> Ive had the same experience as far as preventing me from buying another wheelset. Its actually a good thing....However, i would like a set of lightweight 24mm carbon tubulars for racing. The problem is I would want the power data from the race to see how im looking when i eventually get dropped.
> 
> In this case the stages would be better for me....Maybe i could just run a carbon tubular on the front but who does that?!


You are also forgetting that when you get a flat rear tire in a race and use a neutral support (or your own) wheel, you lose power data with a Powertap (unless your spare wheel has a Powertap as well). BTW ... I know this from experience


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## Srode (Aug 19, 2012)

Why you can move your tire and cassette to the new wheel set with a power meter of course saving that additional $150 and making the cost equal. I have 2 power tap wheels, no problem with either of them zeroing immediately.


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## mikerp (Jul 24, 2011)

knezz said:


> I want to be able to save my rides and note the terrain to find out how I’m doing on inclines by the degree of the inclines and length. I want to be able to what my progress in output. I’ve been riding for a little more than 3 weeks with only about 300 miles under my belt. I feel the Power Meter is essential in tracking my progress as well of showing what changes in techniques work for me.</SPAN>
> 
> My goals are to lose some weight, be able to keep up or eventually issue some pain on group rides and next season do a few centuries. </SPAN>


You don't need a powermeter for your needs.
A bike computer that tracks (location, cadence, heart rate, speed) is all you need. IE a Garmin 510 with the data shown on Garmin connect will show you the ride with elevation, heart rate, cadence, speed; everything you need for what you laid out. While a powermeter is a great tool, it should be used in a specific manner. IE spend an hour a month doing a FTP test (on a route suited for it or on a trainer), build a training plan based on your FTP, recycle, recycle, etc. BTW these rides don't lend themselves for group efforts. If you don't like crunching numbers and reading books to learn how to do this you'll be paying someone else to do it for you.
My suggestion, if you don't have a good computer get one, put in base miles, figure out how to put in more mile every week. IMO with 300 miles under your belt a powermeter is the last thing you need.


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## spade2you (May 12, 2009)

I would agree it's overkill for 300 miles. I think I had my road bike for about 3 years before I got a power meter. I picked up some fancy schmancy wheels and an ultralight bike before I got the power meter. Really wish I had the power meter first. I don't see any reason to avoid getting a Stages or Power Tap with today's prices.


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## tom_h (May 6, 2008)

mikerp said:


> You don't need a powermeter for your needs.
> ... . IMO with 300 miles under your belt a powermeter is the last thing you need.


*... +1*


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## knezz (Aug 10, 2013)

Originally Posted by mikerp 
You don't need a powermeter for your needs.
... . IMO with 300 miles under your belt a powermeter is the last thing you need



###Why do you say it is the last thing I need? ###





tom_h said:


> *... +1*


My thoughts are the opposite ( just novice thinking which can be dangerous and expensive).

i'm thinking if I want to improve quicker a power meter would help a lot in seeing what methods and changes allows for better output by having something extremely measurable.

Am I on track or just wrong?


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## tom_h (May 6, 2008)

knezz said:


> ....
> i'm thinking if I want to improve quicker a power meter would help a lot in seeing what methods and changes allows for better output by having something extremely measurable.
> 
> Am I on track or just wrong?


Without knowing your present aerobic endurance capabilities ... as a new cylist almost any cycling you do will result in significantly improved fitness over the next 3-6 months ... improvements will come quickly.

I would concentrate on riding regularly, and as many weekly hours as practical for you, whether it's 5 hrs or 15 hrs you have available. 

Gradually ramp up your volume and/or intensity, and avoid "junk miles", where you are coasting a lot, or the riding feels too leisurely and easy. 

The other 2 key aspects of training are nutrition & adequate sleep/rest, which most good websites or books will cover in more depth.

A heart rate monitor is nice to have but even that isnt essential in the first 3 mos.

For many/most people, their fitness will improve more quickly if they have training partners, group rides, or a cycle club which continuously pushes them slightly beyond their comfort zone ... I don't recommend going out right away & trying/failing to ride with some group @ 27+ mph !!

If you still feel motivated and excited in 9 mos, then think about a PM.

BTW, my observation has been it takes 2 or more years for a particular PM design to become sufficiently mature, stable, and bug-free so it's useable as a tool, instead of an annoyance. 

There are many new PMs coming to market, but the only 3 "established" ones today remain SRM, Quarq, and Powertap.

Also, a nice comparison summary and selection criteria for PMs at:
Alex's Cycle Blog: Which power meter?


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## knezz (Aug 10, 2013)

tom_h said:


> Without knowing your present aerobic endurance capabilities ... as a new cylist almost any cycling you do will result in significantly improved fitness over the next 3-6 months ... improvements will come quickly.
> 
> I would concentrate on riding regularly, and as many weekly hours as practical for you, whether it's 5 hrs or 15 hrs you have available.
> 
> ...


Very very helpful. Thanks.


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## kmak (Sep 5, 2011)

I bought a Powertap very early in my cycling experience and have found it very very useful. I am purely recreational, but don't mind what I spend on the sport.

It is very useful in understanding effort, what you can sustain for how long (on flats, up hills, into the wind), and for structured training.

I have found the Powertap to be kind of buggy - have had to do a firmware "update" three times to correct whacky power readings (even after calibration).


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## danl1 (Jul 23, 2005)

First: I prefer the powertap option. IMO, better a wheel that can move between bikes than a bike that can move among wheels, but folks take different approaches to that thought. No wrong answer. 

But really, you don't need it just yet. You still have a lot of growth in the general sense of learning about your body, and how to train effectively. And contrary to popular belief / hope, a power meter will not make you stronger. It will only measure your status / progress. It won't hurt, and can even be useful, but it's a precision instrument. Think of fitness like sharpening a blade: You start with a hammer, then get out a grinder, then start on the stones, and finish with a strop. Really, the power meter is the strop. You still need a grinder. Fine to have it along, and they can be fun if you are a data geek, but you are a ways away from the time when having a meter (or not) will really change the outcomes. 

Here's a little blurb from Allen Lim, who used to shill Powertap. A search will show a lot of folks quoting him when justifying how "critical" their purchase is. Ummm.

Training without a Power Meter Explained by Dr. Allen Lim | Competitive Cyclist

Nothing wrong with having one, and if you really get into cycling you'll want it anyway. But - it's technology. It gets cheaper, better, and lighter with each passing year.


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## tom_h (May 6, 2008)

re the Stages PM limitation to left-crankarm only ... on the Google Wattage forum, there are a few early adopters of the Garmin Pedal PM, and some have reported left-right imbalances as much as 45-55 left-right (or right-left). 

The imbalance isnt necessarily bad, it may be an unavoidable by-product of your body's biomechanics. It's also unknown whether the imbalance shifts over time, due to fatigue, injury, training, whatever.

So with Stages PM, doubling the left-crank power to extrapolate overall power has some potentially big sources of errors. If I was trying to improve my FTP by 5% over a season, the Stages would be a non-starter for me.


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## tom_h (May 6, 2008)

FYI, here's a detailed breakdown and trends of powermeter usage at the Ironman World Championships @ Kona
Alex's Cycle Blog: Power meter usage on the rise at Kona


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## knezz (Aug 10, 2013)

tom_h said:


> re the Stages PM limitation to left-crankarm only ... on the Google Wattage forum, there are a few early adopters of the Garmin Pedal PM, and some have reported left-right imbalances as much as 45-55 left-right (or right-left).
> 
> The imbalance isnt necessarily bad, it may be an unavoidable by-product of your body's biomechanics. It's also unknown whether the imbalance shifts over time, due to fatigue, injury, training, whatever.
> 
> So with Stages PM, doubling the left-crank power to extrapolate overall power has some potentially big sources of errors. If I was trying to improve my FTP by 5% over a season, the Stages would be a non-starter for me.


Thank you for the reply.

The left crank arm and doubling gave me pause but a few others said that isn't an issue. Would anyone else like to chime in on the issue?

Also, how does Powertap allow for left/right measuring?


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## ukbloke (Sep 1, 2007)

tom_h said:


> re the Stages PM limitation to left-crankarm only ...


I use power numbers for pacing on hill climbs and sometimes play with my pedal action (cadence, spin, smoothness, etc.) to try to improve my performance. I have a nagging concern with Stages that over time I would subliminally or even conciously "optimize" my pedaling style to increase my power numbers by favoring the left leg. In this case free watts does not equate to free speed!


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## ukbloke (Sep 1, 2007)

tom_h said:


> FYI, here's a detailed breakdown and trends of powermeter usage at the Ironman World Championships @ Kona


My guess is that PowerTap is unrepresented in this sample (compared to total PM sales) because of the aero wheels used by triathletes. I bet that serious Ironman competitors have a "quiver" of carbon wheels that they can choose from based on course/wind conditions, so it makes no economic sense for them to put the PM in the rear wheel.


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## ukbloke (Sep 1, 2007)

knezz said:


> Also, how does Powertap allow for left/right measuring?


PowerTap measures aggregate power (left + right sum). This is accurate but it cannot distinguish left versus right. The value of left versus right balance measurement is debated, and the jury is still out. I think most would agree that accurate aggregate power measurement is required, and that left-right balance is a maybe nice-to-have feature on top of that.


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## tom_h (May 6, 2008)

ukbloke said:


> My guess is that PowerTap is unrepresented in this sample (compared to total PM sales) because of the aero wheels used by triathletes. I bet that serious Ironman competitors have a "quiver" of carbon wheels that they can choose from based on course/wind conditions, so it makes no economic sense for them to put the PM in the rear wheel.


Right ... and disc rear wheels are popular ... and I'm not aware of any powertap disc wheels.


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## mikerp (Jul 24, 2011)

tom_h said:


> Right ... and disc rear wheels are popular ... and I'm not aware of any powertap disc wheels.


HED Jet Disc , Zipp Sub9, etc


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## tom_h (May 6, 2008)

FWIW, the Quarq Elsa PM also can indirectly measure left-right balance, since the crank "knows" its position via a BB-mounted magnet. 

The slightly heavier and ~$400 cheaper Quarq Riken PM does not, but I suspect it's only a firmware difference inside the Quarq.

SRM doesn't presently offer left-right, but I suspect it would be straightforward to add ... wouldnt be surprised if it's in the next model year.

As ukbloke commented, it's maybe "nice to have" if all the other, truly critical PM functions are there (accuracy, low drift, reliability) ... but I wouldnt pay much extra for it. I ended up buying the less-expensive Quarq Riken last spring, to replace a Powertap wheel.


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## mikerp (Jul 24, 2011)

tom_h said:


> SRM doesn't presently offer left-right, but I suspect it would be straightforward to add ... wouldnt be surprised if it's in the next model year.


Per an interview at Interbike it is coming, rechargeable battery as well (MTB first from memory). No price breaks though.


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## knezz (Aug 10, 2013)

ukbloke said:


> I use power numbers for pacing on hill climbs and sometimes play with my pedal action (cadence, spin, smoothness, etc.) to try to improve my performance. I have a nagging concern with Stages that over time I would subliminally or even conciously "optimize" my pedaling style to increase my power numbers by favoring the left leg. In this case free watts does not equate to free speed!


I would think that if someone is right-footed the would have a little more push with that side?


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## ukbloke (Sep 1, 2007)

knezz said:


> I would think that if someone is right-footed the would have a little more push with that side?


Maybe, but it doesn't really make any difference.

Consider 3 riders, Tom, Dick and Harry. All are the same weight, ride the same equipment and all put out an average 300W on the same climb and all therefore finish in the same time. Tom has a left:right distribution of 40:60, Dick is 50:50, and Harry is 60:40. Compare the reported wattages if they were measured with different PMs.


*Rider
**Stages
**Vector
**PowerTap
*Tom240W300W, 40:60 ratio300WDick300W300W, 50:50 ratio300W
Harry360W300W, 60:40 ratio300W

<tbody>

</tbody>
All these are +/- 2% error, which is only 6W on the 300W average. Stages is +/-60W, that's 10x worse. Note that the spread from 240W to 360W (50% more) is comparable to the power ratio between a relatively untrained amateur and a top-flight pro. Putting this bluntly, if a PM cannot definitively distinguish those 2 cases, then it's an abject failure IMHO.

Now the Stages argument goes that this measurement is OK for each of Tom, Dick and Harry because their left:right ratio is a constant and they can just use a self-relative power comparison. But what if it isn't constant. What if Tom or Harry works on their pedal style and improve to 50:50 though still put out an average 300W because they are aerobic limited. Tom likes his free 60W. Harry does not like his lost 60W. Both are confused that their time on the climb has not changed despite huge changes in the reported watts.

Now 40:60 or 60:40 may be an extreme case. But consider that the 2% measurement error bound corresponds to a pedal imbalance of just 49:51 or 51:49. Basically unless you have a near perfect 50:50 ratio the error from the 2x heuristic will exceed the measurement error.


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## arai_speed (Aug 19, 2003)

ukbloke said:


> Maybe, but it doesn't really make any difference.
> 
> Consider 3 riders, Tom, Dick and Harry. All are the same weight, ride the same equipment and all put out an average 300W on the same climb and all therefore finish in the same time. Tom has a left:right distribution of 40:60, Dick is 50:50, and Harry is 60:40. Compare the reported wattages if they were measured with different PMs.
> 
> ...


Where are you getting those numbers from?


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## ukbloke (Sep 1, 2007)

arai_speed said:


> Where are you getting those numbers from?



This is all simple math. It all follows from the assumptions given in the first paragraph. Consider a 40:60 split of 300W. That is 120W on the left and 180W on the right. Stages will report 2 x left which is 240W.


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## danl1 (Jul 23, 2005)

tom_h said:


> re the Stages PM limitation to left-crankarm only ... on the Google Wattage forum, there are a few early adopters of the Garmin Pedal PM, and some have reported left-right imbalances as much as 45-55 left-right (or right-left).
> 
> The imbalance isnt necessarily bad, it may be an unavoidable by-product of your body's biomechanics. It's also unknown whether the imbalance shifts over time, due to fatigue, injury, training, whatever.
> 
> So with Stages PM, doubling the left-crank power to extrapolate overall power has some potentially big sources of errors. If I was trying to improve my FTP by 5% over a season, the Stages would be a non-starter for me.


I'm not sure I understand this logic. Fundamentally, the accuracy of the number doesn't matter, but the precision does. I'm not convinced that leg imbalance matters at all - it's probably just a biometric reality. Increase your FTP by 5%, and chances are best that both legs are going to increase by 5%. But we'll need to see more real-world two-leg data to know that for sure. And we don't know how much of that left-right balance is measurement / calibration error between the two pedal units.

OTOH, I measure gross delivered power via powertap, so what do I know ?


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## danl1 (Jul 23, 2005)

ukbloke said:


> PowerTap measures aggregate power (left + right sum). This is accurate but it cannot distinguish left versus right. The value of left versus right balance measurement is debated, and the jury is still out. I think most would agree that accurate aggregate power measurement is required, and that left-right balance is a maybe nice-to-have feature on top of that.


Apologies for the slight fussiness with language: Accuracy isn't at all important; precision is. That is, it doesn't matter at all if your PM says 150 instead of 170. It matters rather a lot if it says 150 one day and 170 the next, if the truth is that the same power was exerted both days.

Not meant to be snarky. Really only adding to your comment: left-right is (sort of, maybe) about accuracy. But it is the repeatability of measurement (consistency, if you prefer) that matters more. IMO, axle-based measurements (whether hub or BB) might have a better shot at that.


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## ukbloke (Sep 1, 2007)

danl1 said:


> ... probably ... chances are ... know that for sure ... don't know


That's too much uncertainty for me. Why should I buy into those unknowns when a PowerTap is the same price?



danl1 said:


> OTOH, I measure gross delivered power via powertap, so what do I know ?


Me too :thumbsup:


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## igotyofire (Nov 27, 2011)

There is another thread that mentions people having to rebuild their powertap meters. My question is does the stages need to be rebuild ed ever or serviced?


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## ukbloke (Sep 1, 2007)

igotyofire said:


> There is another thread that mentions people having to rebuild their powertap meters. My question is does the stages need to be rebuild ed ever or serviced?


PowerTaps are a hub. Hubs need to be serviced. Sometimes the electronics/gauges fail, then Saris fixes them, either under warranty for free, or not under warranty for money. It is a removable pod on the latest PowerTaps.

Stages are bonded to a crank arm. Sometimes they fall off (less frequently now), sometimes the electronics/gauges fail, then Stages will send you a new one, for free when under warranty. We'll see about outside of warranty when they get to that point.

Good support is important. Both companies have good support.


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## aclinjury (Sep 12, 2011)

The Stages of today is much improved compared to the initial release (which was horrible). I think Stages is ready for primetime now.

edit:
well i'm gonna have to take my words back. After further testing, the Stages seem to be quit off compared to the Powertap.


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## redroab (Feb 13, 2014)

For those of you saying "you don't need a power meter," what do you think of the cycleops powercal? It gets you pseudo-power data for $100- worse than a power meter, but probably much much better than strava et al "power" data. I've been thinking about picking this up. What do you folks think?

CycleOps PowerCal In-Depth Review | DC Rainmaker


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## ukbloke (Sep 1, 2007)

redroab said:


> For those of you saying "you don't need a power meter," what do you think of the cycleops powercal? It gets you pseudo-power data for $100- worse than a power meter, but probably much much better than strava et al "power" data. I've been thinking about picking this up. What do you folks think?


Waste of time and money. IMHO, worse than not using a power meter at all.

If you really want to estimate power without a power-meter, simply ride up a well-chosen hill (e.g. 20 minutes long at steady 5-10%) and measure your time.


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## aggarcia (Aug 28, 2009)

I think any rider can use a power meter to their advantage. I went with the Stages. I had some nice wheels and to get a comparable powertap wheelset ( the $900 set is not very light weight ) I was spending ~$1700-2000. 

I am not a racer, but a power meter is the best pacing tool out there. HRM has too many influences that make readings not comparable from ride to ride. Watts takes the variables out of comparing your ride numbers. My biggest problem was I had my Stages for 6 weeks before my bike was stolen and I had already grown accustomed to pacing my rides by power output. 

There are advantages and disadvantages to all the power meters. You have to figure out what works best for you.


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## ziscwg (Apr 19, 2010)

redroab said:


> For those of you saying "you don't need a power meter," what do you think of the cycleops powercal? It gets you pseudo-power data for $100- worse than a power meter, but probably much much better than strava et al "power" data. I've been thinking about picking this up. What do you folks think?
> 
> CycleOps PowerCal In-Depth Review | DC Rainmaker


I'd pass on this too. If it could take into account grade you were on, then it might be better. That does nothing for a headwind, but what do you expect for$100

I think perceived effort, HR and time on that segment/section would be more consistent.

The whole point of a power meter is consistent numbers. Even if the numbers are 100 watts off, they are still useful to you if they are consistent. You can't brag you hit 800 watts on that hill, but you will see when you improve with consistent numbers.


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## redroab (Feb 13, 2014)

No power meter accounts for a headwind or a grade. They simply account for your power output. Your speed is what is affected by the headwind or grade. The _idea_ is that by some voodoo cycleops is able to infer power from how your heart rate is changing. If you look at DC Rainmaker's results, they seem to indeed be quite good.*** Nothing like a power meter, but very impressive for an eighth of the price. Basically, ziscwg, I can see reasons why you would pass on this, but I don't think you articulated them well. 

ukbloke, thank you for the reply. I take it with a grain of salt however, because I disagree with your take on the stages PM. Not because there is anything wrong with your math or logic, but you and I just disagree on what are acceptable levels of error (or what constitutes an abject failure). That being said, if I were competing at a high level I would indeed pass over the stages.

*except during short intervals


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## igotyofire (Nov 27, 2011)

aclinjury said:


> The Stages of today is much improved compared to the initial release (which was horrible). I think Stages is ready for primetime now.


Improved in what way?


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## tvad (Aug 31, 2003)

I've been watching this discussion (and others) for some time as I try to discern a favorite among users of the Stages Cycling or Powertap meters. No clear cut winner has come forth as far as I can tell, and since I rotate wheels on my bike, I decided to purchase a Stages. I'm hopeful it performs well and any aforementioned issues (e.g. battery life) have been addressed. I'm not particularly concerned about the left leg only element of the Stages.

I decided to also purchase the Protection Plan, since a crash could wipe out the $899 investment in a hurry. At least for $70/year my purchase is protected for two years.


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## Drew Eckhardt (Nov 11, 2009)

redroab said:


> For those of you saying "you don't need a power meter," what do you think of the cycleops powercal? It gets you pseudo-power data for $100- worse than a power meter, but probably much much better than strava et al "power" data. I've been thinking about picking this up. What do you folks think?
> 
> CycleOps PowerCal In-Depth Review | DC Rainmaker


It's an easy way to incorporate an approximation (dcrainmaker's test showed a 10% TSS error versus the Power2Max crank-spider unit) of mountain bike and other powermeter-less rides into your training load and stress balance calculations when you're using a power meter for road rides.

It's a good marketing move to get people starting to train with heart rate into the Cycleops brand where some fraction of those customers will progress to power meters and be more likely to buy a PowerTap hub than a similarly priced Stages crank arm or Power2Max crank spider.

Otherwise you'll do at least as well training with heart rate using a conventional strap and software supporting the TRIMPS model of training stress like Golden Cheetah (free and works on Windows/Mac/Linux).


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## aclinjury (Sep 12, 2011)

igotyofire said:


> Improved in what way?


- they are more consistent with temperature change now
- the glue bonding is improved (although it was not a big failure to begin with, and those that became unbond was promptly warranted by Stages)
- better battery life
- better at giving your a steady reading (instead of laggy and then spike)

Stages have working hard with their firmware that's for sure.


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## aclinjury (Sep 12, 2011)

redroab said:


> No power meter accounts for a headwind or a grade. They simply account for your power output. Your speed is what is affected by the headwind or grade. The _idea_ is that by some voodoo cycleops is able to infer power from how your heart rate is changing. If you look at DC Rainmaker's results, they seem to indeed be quite good.*** Nothing like a power meter, but very impressive for an eighth of the price. Basically, ziscwg, I can see reasons why you would pass on this, but I don't think you articulated them well.
> 
> ukbloke, thank you for the reply. I take it with a grain of salt however, because I disagree with your take on the stages PM. Not because there is anything wrong with your math or logic, but you and I just disagree on what are acceptable levels of error (or what constitutes an abject failure). That being said, if* I were competing at a high level I would indeed pass over the stages*.
> 
> *except during short intervals


Team Sky elected to use Stages. Being that Sky is perhaps the most methodical and science oriented team in the peloton, it's safe to say Stages is pretty darn good.

(Sky approached Stages. Stages didn't come to Sky begging for sponsorship).


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## robdamanii (Feb 13, 2006)

Personally, I'll never use a powertap again. 

Mine worked fine for about 3 years. Then failed. Bad torque tube. Rebuild only has a 1 year warranty and even the powertap rep that I spoke with said that "yeah, you have to replace the electronics every couple years or so, that's their lifespan."

I'm going Stages for my racing bike (although the 4-6 week supply issue is asinine: they are advertising and selling and putting themselves into back order status because they can't/won't hire any further staff???) and won't be constrained to any one wheel or wheelset, nor will I suffer any weight penalty for it.


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## mikerp (Jul 24, 2011)

aclinjury said:


> (Sky approached Stages. Stages didn't come to Sky begging for sponsorship).


Please provide a link to this.


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## 41ants (Jul 24, 2007)

Actually, Stages paid to have Sky use their product. The word on the street is that it was well in the six figure neighborhood.


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## Wookiebiker (Sep 5, 2005)

41ants said:


> Actually, Stages paid to have Sky use their product. The word on the street is that it was well in the six figure neighborhood.


Pretty much all component, frame, helmet, clothing manufacturers are paying teams to use their equipment ... as well as giving them free equipment to use.

Teams generally don't use stuff for free ... they have operating expenses and change manufacturers all the time because they receive better deals from other companies. To them the stuff they ride is just a tool, it's the rider that makes it fast, so the more money they can get for what they ride, the better the riders they can bring on the team ... which leads to better success and the more they can charge companies for using their gear.


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## tom_h (May 6, 2008)

robdamanii said:


> ...
> Mine worked fine for about 3 years. Then failed. Bad torque tube. Rebuild only has a 1 year warranty and even the powertap rep that I spoke with said that "yeah, you have to replace the electronics every couple years or so, that's their lifespan."
> ... .


That seems improbable, I know many who've been using powertaps many years without issues.

Now maybe if you're riding them daily in rainstorms in a tropical climate, and nothing ever dries out, it's a different story.


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## robdamanii (Feb 13, 2006)

tom_h said:


> That seems improbable, I know many who've been using powertaps many years without issues.
> 
> Now maybe if you're riding them daily in rainstorms in a tropical climate, and nothing ever dries out, it's a different story.


I don't disagree that you probably have people who are using them no problem. Doubtful that the technology is terribly different than SRM, and there are people using 10 year old SRMs. 

This is what the rep told me over the phone. My N=1 says that I'm done with them. I've got plenty of teammates on them who've had theirs for years no problem. 

It's also a convenient excuse to move to a crank/crankarm based unit since I swap wheels out frequently.


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## tom_h (May 6, 2008)

re "Stages vs Powertap", I'd say neither ;-)

Backcountry.com is having one of their 20% off sales, thru Monday Memorial Day, and you can buy latest generation Quarq Riken crank powermeter for about $1315 (depending on BB style). 

Yeah, still about $500 more than cheapest PT or Stages, but with Quarq :
-- you get real 2-legged power, not an approximation like Stage's left leg only.
-- much lighter than any PT, regardless of price point.
-- if your existing crank was incompatible w/ Stages, then that option is off-the-table anyway.

BTW, all the newer Quarq Riken & Elsa PMs are vastly more stable Zero Offset drift than previous generations, especially when latest firmware is installed. Typical ZO drift before,during, and after 4+ hr rides is 10-15 points, equivalent to just 3.0-4.5 watts @ 90 rpm cadence ... a +/- 1.50 - 2.25 watt uncertainty.

SRM's ZO stability was one of their prime features, but IMO Quarq equals it now and the cheapest SRM starts at about $2500.

The Quarq that Ray uses ( @ the popular DC Rainmaker website) is 1-2 generations older, so be careful about drawing conclusions. He points that out, but it's easy to overlook.


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## tom_h (May 6, 2008)

danl1 said:


> I'm not sure I understand this logic. Fundamentally, the accuracy of the number doesn't matter, but the precision does. I'm not convinced that leg imbalance matters at all - it's probably just a biometric reality. Increase your FTP by 5%, and chances are best that both legs are going to increase by 5%. ...


Some data on the interwebs has been showing up, that that the left-right balance is not a constant.

The data I've seen shows balance changing as a function of power output, and it's not insignificant.
eg: On Bicycles, and.... what else is there?: Search results for stages

I also suspect, but haven't come across hard data yet, that L-R balance may vary by level of fatigue during a race or ride.


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## aclinjury (Sep 12, 2011)

tom_h said:


> Some data on the interwebs has been showing up, that that the left-right balance is not a constant.
> 
> The data I've seen shows balance changing as a function of power output, and it's not insignificant.
> eg: On Bicycles, and.... what else is there?: Search results for stages
> ...


I've both the PT G3 and Stages. Recently I posted a thread asking if Stages was under-reporting wattage. There's a long discussion with good info from very knowledgable posters (if you want to read it).

Since then, I've done some extensive testing on my rides. What I found is that when you ride on the road (not on the trainer), and ride at around 85% - 90% threshold (which is what one should do in a training ride), then right/left imbalance in inconsequential. The reason apparently for most people, the right and left legs produce closer power at a workload is that is close to maximal.

However, if you're just out droning at say 50% - 60% threshold, then this is where the wattage difference between the PT and Stages is greater. So this could mean that at lower workload, we tend to favor one leg over the other. However, one has to keep in mind that at 50%,60% threshold, it's not considered real adaptive training, it's a recovery ride, so wattage accuracy is not too important.

The sort of rides I'm testing the Stages is like 2-3 hr ride while holding about 90% FTP for the entire duration. Under this sort of ride, the Stages tracks almost exactly like the PT.

However, when on the TRAINER, this is when the Stages (at least in my case), seem to under-report wattage a lot! I mean by 10%! This doesn't happen when you actually ride the bike on the road. Not sure why riding on the trainer would do this to Stages (and this also happens to a buddy who has Stages too).


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## Fireform (Dec 15, 2005)

I have a powertap and a stages. The stages resides on a race bike where I alternate between two wheelsets, and the powertap on a training bike where I use only one alloy wheelset. I like them both after many thousands of miles on each. The powertap seems to report a little lower on average. If I had to give up one of them it would be the powertap.


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## aclinjury (Sep 12, 2011)

Fireform said:


> I have a powertap and a stages. The stages resides on a race bike where I alternate between two wheelsets, and the powertap on a training bike where I use only one alloy wheelset. I like them both after many thousands of miles on each. The powertap seems to report a little lower on average. If I had to give up one of them it would be the powertap.


Have you ever tried to ride the Stages on the trainer (not on the road) and see what sort of power reading it's giving out? Me and a buddy found out that when riding our Stages on the trainer, the Stages under report wattage by quite a bit. This doesnt happen on the road. So I'd definitely be curious about your Stages on the trainer


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## Fireform (Dec 15, 2005)

Because of the bikes they're on I've used the stages on the trainer very little (expensive tubulars on those wheels). I've thought about mounting the powertap on that bike and comparing the two meters in a trainer workout but I haven't gotten around to it. Maybe this week.


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## spdntrxi (Jul 25, 2013)

aclinjury said:


> Have you ever tried to ride the Stages on the trainer (not on the road) and see what sort of power reading it's giving out? Me and a buddy found out that when riding our Stages on the trainer, the Stages under report wattage by quite a bit. This doesnt happen on the road. So I'd definitely be curious about your Stages on the trainer


I have but not much... so far it's pretty close.... but I have also previously edited my wahoo kickr slope to match how I felt on the road with my Powertap wheel. I found a sustained climb that was a constant 3%..kept my cadence level and tried to hold my power constant. Kept playing with the wahoo slope until it "felt" right. I recently got a stages PM on my wifes Madone and for me the stages is reading 3-4 watts higher then the wahoo kickr. Example if I use ERG mode on the kickr with 200w..then check the stages output on another device usually the stages is reading 203 or something similar.


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## aclinjury (Sep 12, 2011)

spdntrxi said:


> I have but not much... so far it's pretty close.... but I have also previously edited my wahoo kickr slope to match how I felt on the road with my Powertap wheel. I found a sustained climb that was a constant 3%..kept my cadence level and tried to hold my power constant. Kept playing with the wahoo slope until it "felt" right. I recently got a stages PM on my wifes Madone and for me the stages is reading 3-4 watts higher then the wahoo kickr. Example if I use ERG mode on the kickr with 200w..then check the stages output on another device usually the stages is reading 203 or something similar.


Intereting data point. Thanks.

I'm still continuing to test the Stages here. So far, and like I said above, Stages are consistent with my PT when the effort is being done on the road at 80%+ FTP workload. At 100% FTP or greater, the Stages track almost exactly to the PT. And Alex (who posts a lot in the Training forum, he's a coach) even mentioned that at near or maximal power, our legs produce power that are closely matched. And honestly, to me it's the near maximal or maximal effort that is when I care to pay attention to my wattage (because this is where adaptive training really begins). At 50%/60% FTP, i'm just droning, not need to pay attention to wattage.


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## Fireform (Dec 15, 2005)

I did a comparison of my stages and powertap meters tonight, in a long workout on my trainer. Both head units were reading out 10 second averages. I was impressed--they were within two watts of each other over the range of effort, in this case from 100 to 850 watts. Way closer than I expected. 

The 10 second smoothing probably helped, but that's what I normally have on my display. As far as I'm concerned they're interchangeable.


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## pantani (Jun 26, 2014)

Hello all,

I had some thoughts on the subject since I'm having a similar dilemma. I am currently going back to training after a 2 years of absence, and was thinking to start using a power meter. The choice is limited down to Powertap and Stages since everything else is too expensive, but I have some concerns about either:

Powertap: I use two different "system wheel sets" one for training and one for racing. So adding a third wheel set and using only this doesn't seem very smart or justified.

Stages: Since my group set is not being produced anymore (Dura Ace 7800 from 2006), it is possible that if some parts break down I'll have to change to a different model of group set. Also I don't know when the wireless SRAM group will get to the market, but it could be a potential upgrade at some point. So getting say a Stages 105 or ultegra left crank arm now, it could soon be rendered useless. On the other hand perhaps one could interchange cranksets between different Shimano and SRAM groups?

It seems to me that there is currently no perfect power-meter solution... The vector pedals would address all of the above, but the price is still very high, and they seem quite fragile. Also they are bound to one particular pedal system.


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## tom_h (May 6, 2008)

*Quarq introduces "bare" PMs at lower price*

I've noted that Quarq (business unit of SRAM), a major mfr of crank-based PMs, is now also offering their systems as a "bare" PM cransket _without _chainrings. 

This allows Quarq to drop the price of the Riken model, for exmpl, to as low as $1200. 

And retailers like Backcountry.com, will usually offer 20% discounted sales 2-3 times per year: down to $960.

So if you already have an existing crankset with good condition, compatible chainrings that you can move to the bare Quarq , this can be a very good option. 

This puts Quarq into Stages price range, and you get a "real" 2 leg PM.

Do note Quarq chainring install requires a decent torque wrench, and an ability & willingness to follow written directions ;-)


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## floralagator (Jun 18, 2014)

pantani said:


> Hello all,
> 
> I had some thoughts on the subject since I'm having a similar dilemma. I am currently going back to training after a 2 years of absence, and was thinking to start using a power meter. The choice is limited down to Powertap and Stages since everything else is too expensive, but I have some concerns about either:
> 
> ...


I run SRAM Rival on both my bikes so I can switch the Stages between them. Road bike is full SRAM group while TT bike runs Dura Ace 7800 like you except the crank. Even when SRAM comes out with e group, you'll need to run Rival or some other alloy cranks to use a Stages.


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## runabike (Jun 18, 2013)

aclinjury said:


> , and ride at *around 85% - 90% threshold (which is what one should do in a training ride*), then right/left imbalance in inconsequential. The reason apparently for most people, the right and left legs produce closer power at a workload is that is close to maximal.
> 
> * However, one has to keep in mind that at 50%,60% threshold, it's not considered real adaptive training,* it's a recovery ride, so wattage accuracy is not too important.


You should have just stuck to the power meter comparisons rather than interjecting such random, awful training advice.


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## Blue CheeseHead (Jul 14, 2008)

tom_h said:


> Some data on the interwebs has been showing up, that that the left-right balance is not a constant.
> 
> The data I've seen shows balance changing as a function of power output, and it's not insignificant.
> eg: On Bicycles, and.... what else is there?: Search results for stages
> ...


I have had a PowerTap, have a Stages and utilize a Computrainer on a regular basis during the winter. I am with Danl1 on this, it's all relative. From doing the spin scan on the Computrainer my legs are within 2% of each other and that does not differ with fatigue. If I am measuring an effort based on my left leg at 300 watts it will measure that on Monday or Friday, (it's reproducible) If my right leg is doing 306 watts, fine, I do not see how that would change anything in how I ride or train.

In my opinion the Stages provides enough consistency and precision for the purposes intended.


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## Alex_Simmons/RST (Jan 12, 2008)

Blue CheeseHead said:


> I have had a PowerTap, have a Stages and utilize a Computrainer on a regular basis during the winter. I am with Danl1 on this, it's all relative. From doing the spin scan on the Computrainer my legs are within 2% of each other and that does not differ with fatigue. If I am measuring an effort based on my left leg at 300 watts it will measure that on Monday or Friday, (it's reproducible) If my right leg is doing 306 watts, fine, I do not see how that would change anything in how I ride or train.


Spin scan doesn't tell you what your left and right legs are doing. It can only tell you what happens during each half of the pedal stroke due to contributions from both legs, and that's not the same thing as understanding what each leg is doing. Be very careful in how you interpret such data. It's often not what people think it is.



Blue CheeseHead said:


> In my opinion the Stages provides enough consistency and precision for the purposes intended.


That depends on the purposes intended. For general training and guidance on overall effort levels, I agree. But that's a pretty low-fi application of a power meter. Issues arise when you want to start doing more interesting things with your power meter data.


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## tvad (Aug 31, 2003)

Alex_Simmons/RST said:


> For general training and guidance on overall effort levels, I agree. But that's a pretty low-fi application of a power meter. Issues arise when you want to start doing more interesting things with your power meter data.


Setting aside the debate over sponsorship, Team Sky's use of the Stages power meter suggests to me higher level applications than general training and guidance on overall effort levels.


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## Alex_Simmons/RST (Jan 12, 2008)

tvad said:


> Setting aside the debate over sponsorship, Team Sky's use of the Stages power meter suggests to me higher level applications than general training and guidance on overall effort levels.


On the contrary, the resources that Sky have at their disposal means they have other ways to perform such functions. Plus they do have years of SRM data so it's not like they are starting out totally blind. Sky have decided they can take the sponsors cheque, do the simple stuff, and when they need to dive deeper well they'll do other things, like put the SRM back on, or go to the wind tunnel, or head to the lab. the marginal gains in this instance are financial ones.

Finally, it matters not what level the rider is, it's the quality of the data that is the factor that determines what you can do with it.


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## tvad (Aug 31, 2003)

Alex_Simmons/RST said:


> On the contrary, the resources that Sky have at their disposal means they have other ways to perform such functions. Plus they do have years of SRM data so it's not like they are starting out totally blind. Sky have decided they can take the sponsors cheque, do the simple stuff, and when they need to dive deeper well they'll do other things, like put the SRM back on, or go to the wind tunnel, or head to the lab. the marginal gains in this instance are financial ones.
> 
> Finally, it matters not what level the rider is, it's the quality of the data that is the factor that determines what you can do with it.


I see from your signature you sell SRM & Quarg power meters, so I'll take your comments with that financial bias in mind.


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## Alex_Simmons/RST (Jan 12, 2008)

tvad said:


> I see from your signature you sell SRM & Quarg power meters, so I'll take your comments with that financial bias in mind.


That's true. I'd sell Stages, and other power meters as well but only have distribution access to those particular brands. Not exactly my main gig.

I'm not saying people shouldn't purchase or use a Stages. Merely pointing out the differences and misconceptions and understandings of the issues of power meter data quality, and that people are better off being well informed, than ignorant of the issues before they lay down their hard earned.

Here's a post of mine discussing the power meter options, including the Stages. I consider it to be pretty balanced:
Alex's Cycle Blog: Which power meter?


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## Wookiebiker (Sep 5, 2005)

Alex_Simmons/RST said:


> Finally, it matters not what level the rider is, it's the quality of the data that is the factor that determines what you can do with it.


With that said ... there are few enough people out there that can really do anything with the data to that level, that it's almost irrelevant which power meter most use.

The average, amateur racer on this forum or any other cycling forum just needs a power meter that gives consistent data from day to day. They can pull their FTP from that device and set up training zones from that. That's all that the vast majority of riders need and a Stages, SRM, Quarq, Powertap, etc. will all do that well enough.

If you are a Pro, especially at the top levels ... you "Might" need the extra difference a top end power meter gives, but even then, pro's have been training without power meters since the beginning of cycling and doing just fine, some still do.


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## Alex_Simmons/RST (Jan 12, 2008)

Wookiebiker said:


> With that said ... there are few enough people out there that can really do anything with the data to that level, that it's almost irrelevant which power meter most use.
> 
> The average, amateur racer on this forum or any other cycling forum just needs a power meter that gives consistent data from day to day. They can pull their FTP from that device and set up training zones from that. That's all that the vast majority of riders need and a Stages, SRM, Quarq, Powertap, etc. will all do that well enough.
> 
> If you are a Pro, especially at the top levels ... you "Might" need the extra difference a top end power meter gives, but even then, pro's have been training without power meters since the beginning of cycling and doing just fine, some still do.


Pros are relatively late adopters of power meters, with a few notable exceptions. Most innovation in using power data has come from and is applied by the amateur ranks.

That's probably because it's those with the least power that focus on how to get the very most out of it.

Stages is similar to the old Polar power meter in that it's a gateway drug. Just much easier to use than the Polar was, so it will likely dominate the market share for new users (really it will substantially grow the size of the power meter market pie). Which is all good.

It's still relatively early days for Stages and Garmin Vector. Power meter effectiveness is measured in years, not months.


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