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I want to start training with power. I searched and found a lot of good info on the PT, but I already have the polar s725x. Do you recommend a PT or the polar power kit? Cost and Quality/Performance are pretty much equally important to me. Please let me know your experiences etc.
Thanks!
 

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zhmontana said:
I want to start training with power. I searched and found a lot of good info on the PT, but I already have the polar s725x. Do you recommend a PT or the polar power kit? Cost and Quality/Performance are pretty much equally important to me. Please let me know your experiences etc.
Thanks!
Lots of recent discussions both on the wattage list on Topica and on the power training forum on cyclingforums.com. I'd really recommend asking the question there (and of course searching the archives there first) rather than here, because there really aren't so many people training with power over here.

My $.02 anyway... with the caveat that I've got a PT pro that has been pretty much flawless and that I've not used Polar... the rap on Polar is that it's hard to set up, but that if done properly it's pretty accurate. It may or may not work well while you have the bike mounted in a trainer. This would be a deal breaker for me, since lots of my training over the winter is done on the trainer. Finally, the sample rate is rather long (5s), so it's not going to give you as accurate a picture as a PT or SRM would for short intense efforts (say crits). It'd be fine for TTs and longer work though.

There are lots of polar users out there who swear by them once they are set up correctly. If I were in your shoes, I'd study up on the setup requirements and probably go with the Polar since it's so much cheaper. Then once you're hooked on power, move to a PT/SRM/Ergomo if you feel you need the short term accuracy.
 

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From http://midweekclub.ca/powerFAQ.htm#Q38

Q: My Polar S-710 has been difficult to install. Any suggestions beyond what’s in the owner’s manual?



A: Wattage Forum member Robert Chung has devoted a page to this at his web site: http://tinyurl.com/ijav, and there is a video at the Polar web site http://polarusa.com/consumer/powerkit/installvideo.asp



(Tom Anhalt) The angle of the chain across the sensor and whether or not the sensor module is parallel to the chain do not matter; all that counts is to position the module so the chain is no farther than 30 mm, in all usable gear combinations, from an approximately 1” square area centered on the “middle” mark on the module. If this requirement is met, and if the cadence sensor is properly positioned (which depends on the particular magnet you use), you’ll get consistent readings, otherwise, the chain vibration signal will be weak and the signal processor will tend to “lock on” to signal noise, causing erroneous readings.



Some comments on the Polar installation video:



1. why mark the center of the chainstay? This is the first thing shown, but it’s not used for anything. The location of the module on the chainstay is driven solely by the placement of the magnet on the crank, and then placing the module so that the cadence sensor lines up.

2. the routing of the speed sensor wire just begs for it to get snagged and ripped out. There are much better techniques for routing and securing this wire to the derailleur that will minimize this threat.

3. it is a mistake to make the vertical spacing measurement 5-10 mm in the small-small combo. It’s the wrong end of the range from which to make this critical measurement, since the chain will be much farther away than 30 mm even in the small chainring-large cog combo. I run a pretty “normal” gear setup (53/39, 12-25 cogs), and if I try to run the 39 x13 (which I don’t because of the cross-chaining), the chain actually rubs on the sensor.

4. there is no mention of making sure the chain passes over the sensor in all gear combinations, a significant omission.



Finally, to protect the sensor module, I first tried some mylar, but that didn’t last long. The best thing to do is to grab a couple of black zip ties and wrap them around the module right over the top of the magnetic frequency sensor (that’s where the chain will be pulled down). This way, the chain will rub on the “sacrificial” zip ties instead of the top of the module.
 

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My coach threw a "test bike" bike together with Polar Power and Powertap, and THEN he put the sucker on a Computertrainer.

His conclusion, after both the CT test (whose calibration he trusted, he uses it for lots of athlete evaltuation) and some road riding, was that both systems are good, but that the Polar Power wasn't quite as consistent / reliable as the PT.

Still, if an athlete is looking to get into training with power, he recommends it because it's reliable enough for training purposes and very cost-effective.

Another note he had was the the Polar unit consistently reported higher power than both the computrainer and the powertap, by about 5 to 10%. He says that shouldn't matter, since the main point of reference is yourself.

Hope that helps. I'm going with a powertap, but I don't have a Polar monitor to start with.
 

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Compare closely to a PT the way ... oh, whatever, I won't bother with the analogy.

We've been through this a bunch recently, but I can't find anyone who has actually used it.

Naming it like Apple names computer programs and calling it "Pro" does not make it good. To me it sounds like a "powerguessometer," as one fast_c50 put it.

Where is it "supposed to compare closely" to a Powertap? I'd be interested to read a study, or at least a side-by-side review. I know my HAC4 spits out "power number" that are, um. Well. They say "watts" right beside them, and they go up when I go up hills. That's bout all I can say.
 

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The Polar power meter doens't work very well when the bike is on a trainer. They tell you that in the manual. So the comparison on the computrainer is flawed. I found mine a pain in the rear to install, since there are so many sensors. The plug that connects the wiring harness to to the watch bar mount is flimsy. Mine eventually broke.

I did get what I think were accurate power numbers-- they matched the numbers from the model on analyticcycling.com for ~30 minute climbs. Even if the meter is 10% off, as long as it is consistent, that is all you need. The Polar records in 5 second intervals but the measurement is more frequent, like 1-2 seconds.

The biggest problem with the Polar is that there is no way to display the average power for a lap (interval). Instant power varies quite a bit, making it useless for gauging effort during an interval. I'd recommend something else because of this.
 

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ericm979 said:
The biggest problem with the Polar is that there is no way to display the average power for a lap (interval). Instant power varies quite a bit, making it useless for gauging effort during an interval. I'd recommend something else because of this.
Oh. Well, that's annoying, then.

The biggest piece of advice I hear about new folks to "training with power" is to throw down an interval flag any time you're about to do something -- a climb, a sprint interval, whatev -- so you can take your avg power on a given section. That seems like one of the more useful aspects to training with power, as you say.
 

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totazz13 said:
What about this new iBike Pro? I saw it at www.iBikeSports.com
It's supposed to compare closely to the PT.

It doesn't. It compares closely with a HAC4 more accurately. Look and you can get a HAC4 on the cheap on the interweb.
 

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Coolhand said:
It doesn't. It compares closely with a HAC4 more accurately. Look and you can get a HAC4 on the cheap on the interweb.
I've not seen any comparisons of it with the HAC4... perhaps you can post a link coolhand?

There's an ongoing discussion on the topica wattage list by people who are ACTUALLY USING it right alongside a PT Pro (rather than just speculating that it must suck), including posts of the raw data dumps from both.

For those who are really interested, again, I'd suggest going there for answers rather than getting uninformed group think regurgitation from this board.

BTW, I'm not trying to say the ibike doesn't suck, rather just trying to point folks to actual data and discussions by people using both instead of armchair speculators.
 

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I had my bike shop install my Polor power system (since I already had the 725x) and I've been very happy with it so far. My plan is to use it for a year or so then see where I am as far as 'power training' goes, and see if I want/need to upgrade to a PT or something. In the meantime the Polar system is, in my view, a very cost-effective way to get my feet wet.
 

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shawndoggy said:
I've not seen any comparisons of it with the HAC4... perhaps you can post a link coolhand?

There's an ongoing discussion on the topica wattage list by people who are ACTUALLY USING it right alongside a PT Pro (rather than just speculating that it must suck), including posts of the raw data dumps from both.

For those who are really interested, again, I'd suggest going there for answers rather than getting uninformed group think regurgitation from this board.

BTW, I'm not trying to say the ibike doesn't suck, rather just trying to point folks to actual data and discussions by people using both instead of armchair speculators.
Uninformed? Based on what? I have been following those discussions closely, and it's a fancy hac 4. Except a HAC4 doesn't go completely to pot if the road isn't perfect- which apparently the IBike does.

Feel free to point out some contrary relevant data though, as based on the information provided by the makers, topica users, and various internet touts, it's basically a HAC4 with a few extra variables added. It has no torque measuring mechanism, so it cannot measure power. It can guess at power, based on some measurements you input (source of error #1), some generalized assumptions (#2) and perfect road conditions (#3).

I have trained with power for over three years, and personally run a HAC4, Powertap Pro, Powertap SL, and an SRM Pro Dura Ace. The only real power meters I have not used are the Polar and Ergmo (the very latest version looks interesting, but is tied to the legacy BB style, and the required BB overhaul issues worry me). Been following topica for at least that long, and also been involved in the industry at the IBD level for longer.

So thanks for playing.
 

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Coolhand said:
I have trained with power for over three years, and personally run a HAC4, Powertap Pro, Powertap SL, and an SRM Pro Dura Ace. The only real power meters I have not used are the Polar and Ergmo (the very latest version looks interesting, but is tied to the legacy BB style, and the required BB overhaul issues worry me). Been following topica for at least that long, and also been involved in the industry at the IBD level for longer.

So thanks for playing.
Since you are an expert coolhand, we're glad to have you here, especially with your bonus condescending attitude, since it makes you so much more authoritative.

As a self proclaimed veteran of power training, can you please explain how you put Polar in the "real" power meter category even though it doesn't have a torque measuring mechanism? Curious.

But that's splitting hairs and I'm assuming that you're giving polar a pass because it has proven accurate (or at least "accurate enough") despite the fact that it extrapolates power from chain vibration rather than actually measuring torque. I'm wondering why you haven't adopted at least a wait and see attitude with the iBike, given that it has only been on the market for a few weeks.

The ibike does include an accelerometer, which, I believe is a significant departure from the HAC4 concept. Really can't we call all cyclecomputers just Avocet 15's "with a few extra variables added"?

Again, I'm not saying that the iBike works. I'm saying let's hear from people who are actually using them rather than speculation that it must suck.
 

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Polar

I've used the Polar power meter for the last three years. Every year since I bought it, it dies and has to be sent back to Polar. Luckily for two of those, I was in Spain and Polar Spain was very responsive in replacing it with a new one within a week. The unit is consistent and that is the most important thing when training with power. Yes, it takes a little work to set up but once it's on, it's all ok. Good thing about this system is it is fairly light and allows you to use whatever wheels and cranks you choose. Therefore you can use it in a race without a major equipment penalty. Yes, you can only see current Watts while training but when you get home you can see average Watts over a recorded interval. The Polar software is basic, but good for a beginner.

Two days ago my power meter started acting up again, and I think it is about time for its yearly self destruct. I called Polar USA and the customer service there is terrible. They guy was very non-responsive and just seemed like he wanted to get me off the phone. Everytime I deal with Polar USA the mess something up and they don't seem to care. If my power meter is dead again, I may send it back but I think I'll be moving on to the Ergomo because I just can't stand Polar USA's pathetic excuss for customer service. The Ergomo looks very promising now that you can get it for ISIS or Octalink and it comes with an Ergomo branded version of Cycling Peaks, one of the best programs for power on the market.

The Polar product is great, especially considering the costs of power meters, but due to their lack of a good customer service dept I'd recommend staying away from them.
 

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shawndoggy said:
Since you are an expert coolhand, we're glad to have you here, especially with your bonus condescending attitude, since it makes you so much more authoritative.

As a self proclaimed veteran of power training, can you please explain how you put Polar in the "real" power meter category even though it doesn't have a torque measuring mechanism? Curious.

But that's splitting hairs and I'm assuming that you're giving polar a pass because it has proven accurate (or at least "accurate enough") despite the fact that it extrapolates power from chain vibration rather than actually measuring torque. I'm wondering why you haven't adopted at least a wait and see attitude with the iBike, given that it has only been on the market for a few weeks.

The ibike does include an accelerometer, which, I believe is a significant departure from the HAC4 concept. Really can't we call all cyclecomputers just Avocet 15's "with a few extra variables added"?

Again, I'm not saying that the iBike works. I'm saying let's hear from people who are actually using them rather than speculation that it must suck.

While it's amusing that the individual who started the snark is whining about it now, I will address the more substantive portion of your post, as it is the more interesting issue.

Based on Polar's description and rather extensive discussions on Topica (I posted the link in the last Ibike thread) the Polar does measure the torque, but through the chain in a rather clever mechanism. The issue is two fold really for the Polar, one it is highly sensitive to set-up issues and also can have accuracy issues in certain gear ratios. Two is the cost if you do not already have a compatible Polar HRM, which puts it right into Powertap Pro territory, especially used ones which may be less.

With regards to the accelerometer, this is one of the issues with the non-smooth roads noted on Topica already. Given the discussions on Topica from people using it, and the admissions from the iBike touts I think we are beyond "speculation". Given the rather princely sums these are priced at, their claims that it's a real powermeter and the feedback we have already received, and my previous experience with powermeters I feel I have not taken much of a leap at all in my posts. Extra-ordinary claims like theirs, which runs counter to prior experience merits serious evidence, and I have not seen any yet. Rather, what I have seen supports my position.

My bet these won't get anywhere- information gets around too fast now, and they can be had on the cheap in a year. For someone looking for a powermeter- buy a real powermeter. Right now- that's an SRM, Powertap, Ergmo (latest version only) or a Polar (only if you already have a compatible HRM and money is tight).

However, if you really want one of these things- knock yourself out. I have been wrong before. . . .
 

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I don't know any details about the Polar gadget personally, but I assumed the way it worked was to measure chain tension and chain speed which would give you the power; at least the power the chain delivers to the rear of the drive. Is this not correct?


Dancer
 

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zhmontana said:
I want to start training with power. I searched and found a lot of good info on the PT, but I already have the polar s725x. Do you recommend a PT or the polar power kit? Cost and Quality/Performance are pretty much equally important to me. Please let me know your experiences etc.
Thanks!
I would skip the polar unit. I had one; I bought it because I already owned a 725i. I could only get it to work intermittently. In addition, the power sensor did not fit well on the curved chainstay of my litespeed, and installation was a huge pain in the ass. I ended up selling it on ebay, and I'm planning on purchasing a powertap pro sl.
 

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Just thought I'd let you guys know I fixed my Polar power meter issues, not thanks to Polar though. I started thinking about how it was acting with the old battery and the fact that even after the battery change it was still doing the same thing (shutting itself on and off repetively). I pulled the new battery back out and compared it to the old one. Both are Duracell batteries but the new one as the flat negative end recessed into the body of the battery while to old one is flush with the bottom. I though maybe the spring contact was pushing on it with enough pressure to make good contact and tried placing a thin flat metal washer on the end of the batter to take up the extra space. Works perfect again. :thumbsup: Like I said at the beginning though, Polar was absolutely no help in resolving this.:mad:
 
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