Happy Polar 720 Power Owners?

[jasong]

Have you had good luck using yours with a stationary trainer?

Did you have any issues with the chain dragging on top the chain stay sensor when in the small ring and smaller cogs?

I'm looking forward to finally installing mine after not feeling like I could get it to work on a triple over the summer. Maybe the 39T will be better than the 30T.

I can't seem to get reliable cadence/speed/heart rate (choose two but not three) from the wireless sensors with my 720. It's frustrating as heck, but that'll go away with the wired sensors on the Power.

Count me as a happy PPS user. It took me all of 20 minutes to install and another 10 minutes of check-out to verify all was working correctly.
left balance.

 

[Weisse Luft]

Have you had good luck using yours with a stationary trainer?

Did you have any issues with the chain dragging on top the chain stay sensor when in the small ring and smaller cogs?

I'm looking forward to finally installing mine after not feeling like I could get it to work on a triple over the summer. Maybe the 39T will be better than the 30T.

I can't seem to get reliable cadence/speed/heart rate (choose two but not three) from the wireless sensors with my 720. It's frustrating as heck, but that'll go away with the wired sensors on the Power.

I have yet to try it on a stationary trainer as these bore me to tears. Now rollers at least force me to keep some attention so I might have to slap a magnet on my cheap wheelset if its rainy tomorrow. But I would rather go out..

Yes, the chain does drag the sensor when I am not pedaling. I covered mine with a modified chainstay protector, the clear type so as to see the sensor check light. This made the chain slide easier and keeps it clean. No problems, even backpedaling. I mounted the sensor higher in the front to more accurately parallel the chain line throughout the gear range but I am running a 39-53 with a 12-23 on the rear, nothing too extreme.

 

[upstateSC-rider]

I have a 725 that I'm very happy with and am interested in the power option. Are there any issues with triples vs. doubles?


Thanks.
Lou.

 

[Weisse Luft]

I have a 725 that I'm very happy with and am interested in the power option. Are there any issues with triples vs. doubles?


Thanks.
Lou.

Follow the directions and be sure to mount the chain tension sensor on the middle of the chain span (half the distance from the BB spindle to the rear axle). There is a mark on the sensor for this.

Try to keep in a sensible gear combo, avoiding the big/big and small/small combos. These wear the chain excessively and can cause chain drop/suck so you should naturally avoid...

Bear in mind, pedaling index improvements will help the overall accuracy AND improve your form/efficiency.

 

[rob of the og]

The only difficult bit about installation is having a good think about the routing of the cables - especially around the bottom bracket because you don't want them getting caught in anything.

I agree that the cadence magent is a disaster, but what I did was chop up the plastic casing because the little magnet inside is just the right size to put inside the allen-key bolt in the pedal - it sticks out just right to trigger the sensor.

When I compared the readings to a MAP test done on a Kingcycle I found that the values where identical at the low end, but much lower at the top end. As people suggest, I put this down to the increased frequencies of the resistantance unit on the Kingcycle. The results from the Polar on the road seem entirely consistant with the final Kingcycle values, and the levels I worked back to (using Ric's formulae) 'feel' just right.

So, I'm actually very happy with my Polar power unit. I have it fitted on both bikes for less money than one PT, and I can change the wheels between racing and training without losing the power output.

 

[darnok]

Sounds like they have a different cadence magnet in the US, I have no problem with the one I got her e in Switzerland, a little flat part with a sticky back and a Polar sticker you wrap around your crank to secure it.

My unit has been working fine since I got it this summer, routing the cables is the only tricky part in installation. I put them on the underside of the tubes fixed with duct tape that you cant see unless you turn the bike over. I did not need to raise the

What's funny is that I'm suffering from interference by high/medium voltage power lines that hang much lower here in Europe htn what I've seen in the US. I hardly ever lose the HR signal which is wireless, but the power and cadence readings disappear, although they are wired. I guess this is due to the fact that the entire system is based on a magnetic field.

I did not have to raise the power unit off the chainstay, everything worked fine out of the box with the geometry of my bike.

 

[Weisse Luft]

The power unit communicates with the HR monitor via some kind of digital communication as there are only 2 connections. Its entirely possible strong EM interference from power lines could be interrupting this communication.

On maximum power measurements, remember this unit does not average power and samples at only once every 5 seconds. If you do not maintain even power throughout pedaling cadence, results will vary and comparison with other means will seem inaccurate.

 

[rob of the og]

The power unit communicates with the HR monitor via some kind of digital communication as there are only 2 connections. Its entirely possible strong EM interference from power lines could be interrupting this communication.

On maximum power measurements, remember this unit does not average power and samples at only once every 5 seconds. If you do not maintain even power throughout pedaling cadence, results will vary and comparison with other means will seem inaccurate.

The recording is only every 5 seconds but the number on the screen is an average over the previous revolution of the cranks. Since it records what is on the screen at each 5 sec interval, each sample is an average over the crank revolution immediately prior to the 5 second point. In many ways this is a better algorithm than the SRM or PT where (iIrc) the displayed value is an average over a (albeit very short) timespan, thereby leaving them open to the inaccuracies you describe.

Of course by having a 5 sec minimum interval it does mean that you miss some peaks off your recorded file, ie smoothing is preapplied to the results. Personally though I'm not concerned about any outputs which I couldn't sustain for 5 seconds.

 

[Weisse Luft]

The recording is only every 5 seconds but the number on the screen is an average over the previous revolution of the cranks. Since it records what is on the screen at each 5 sec interval, each sample is an average over the crank revolution immediately prior to the 5 second point. In many ways this is a better algorithm than the SRM or PT where (iIrc) the displayed value is an average over a (albeit very short) timespan, thereby leaving them open to the inaccuracies you describe.

Of course by having a 5 sec minimum interval it does mean that you miss some peaks off your recorded file, ie smoothing is preapplied to the results. Personally though I'm not concerned about any outputs which I couldn't sustain for 5 seconds.

That is odd because on my 720, I frequently record a larger maximum on the monitor (File, Records, Max Power) than on the data file. For example, last night's session recorded 830 W maximum while on the file I downloaded, the maximim was 750 W.

 

[roofrak2]

I have used my Polar Power meter for one year and it has been working well. This winter I removed the power sensor wire that connects to the Bike mount on the handle bars. I had forgotten how the connector connected to the bike mount and rather than pulling off the connector I twisted it off .This caused the three colored wires(red blue Green) inside the black protective wire cover to tear off the three prong connector. The three colored wires are quite easy to solder back on , but I do not know which wire came off which prong.

If any one has had a similar problen and knows the right order of wires or if some one knows how to SAFELY unscrew the three pieces of the conector and reveal the connecting order I would greatly appreciate the information.

BTW the correct ( should you ever need to) way to safely open the three pieces of the connector is:

Pull the connector straight off the bike mount, do not try to twist or screw it off

Hold the two narrowpieces of the connector(the ones with the three pronges in it) FIRMLY as one unit, then unscrew the larger piece (with the grip marks on it and the wire entering it) off, this pieces function is to keeps the wire from being pulled out of the connector.

Then you can SAFELY unscrew the two narrower pieces of the connector and reveal the three colored wires.( do not let the three prongs piece and the black wire get twisted in any way from each other...the middle piece should be the only thing that is turning.

To reconnect... do the reverse order

NEVER unscrew the two narrow pieces of the connector before the wider is unscrewed, you will tear off the three wires !!!

I hope that these instructions are not too confusing BUT I would like to avoid anyone from doing the mistake I did !!!

I hope that someone could help me with the wire color order . I would like to be using the Power meter again this spring it is a good training partner.

Thanks Roofrak

 

[WarrenG]

I hope that someone could help me with the wire color order . I would like to be using the Power meter again this spring it is a good training partner.

Thanks Roofrak

Here you go.

With the black protective covering unscrewed/removed, looking straight at the three little tabs that you will solder to, the three tabs are oriented as a "V". From left to right, Blue, Green, Red.

 

[bucfan471]

Spend a little more get the powertap SL you'll love it.

I am struggling between Powertap and Polar 720 with Power. I have read all the tests and I think I have a grip on pros and cons of each system. Given all my research I am close to getting the 720 with power because of the price difference (the polar power option is about a third the price of powertap pro) but I must say that I haven't read too many comments from people who own the Polar power device and LOVE it. Most comments are complaints about installation or limitations on capturing low power readings etc.

Anyone out there LOVE their Polar power meter?

thx

 

[allenpg]

For what's it worth, I'm happy so far with my Polar power meter and S625X. Of course, I'm saving up for a Powertap for next year... It took my a few tries, but I've gotten my Polar to agree fairly closely with my Computrainer (+/-5%). I know that's not good for a lot of people, but I'm new to competitive cycling and the whole power thing. I'm mainly concerned with following trends in my training. If you like to tinker and don't need the accuracy, I'd recommend the Polar. Otherwise, go for the Powertap. BTW, as a biker/runner, I really like the Polar software.

-Pete

 

[JTE83]

I'm happy with my kits and have 3 of them on 3 bikes. My 3rd one is uncalibrated since I did't put good chain data in yet.

It's a relatively cheap power meter and you can run HED 3's on it unlike a PT.

My other 2 kits give good data but I know they go bad when using the 21 cog or higher.

 

[steve]

I know they go bad when using the 21 cog or higher.

I get readings of 100 watts or less when i'm riding up a 12+% climb at max effort. I know i'm not that fit anymore.....but come on!

not happy

 

[roofrak2]

Thanks Warren for the quick response ...But I am a bit late in reading the order of the wiresthe you posted.

I have one more question to clairify the correct order.
The soldering tabs are equally spaced so there are three ways to look at it...when looking at the soldering taps, is the wide slot on the other side facing up? this would give me the correct orientation for the soldering order of the wires.
Thanks in advance and I hope you can assist one more time
Bert

Here you go.

With the black protective covering unscrewed/removed, looking straight at the three little tabs that you will solder to, the three tabs are oriented as a "V". From left to right, Blue, Green, Red.

 

[tourdelivermore]

I have used this on two bikes now - and I am fairly pleased with it. Mind you, here in Australia it is VERY expensive, so it is vary hard to say I have bought a dud.

My biggest problems with the Power Sensor are -

- the thing has to be perfectly level. It can often get bumped a bit, and then the cadence sensor won't be picked up, etc.
- the cadence magnet falls off all the time. I think have had 4 or 5 magnets now.
- I am always worried about the wire to the chain speed sensor - it looks like it is going to get caught in the chain/sprockets. It hasn't yet, but I feel it is only a matter of time.
- the magnet drags the chain down when you are stopped. This looks weird, but has not caused a problem yet. You have to put a plastic cover on top of the sensor as this chain dragging wrecks the sensor unit.

My problems with the S720i were legion -

- the LCD screen gets a rainbow pattern in low light situations - especially early mornings. It can be that bad you simply cannot read the screen. I returned two units for this problem - eventually giving up and swapping the S720i for a S710i. This seems better, although not perfect.

- the bike functions are poorly thought out - you cannot select combinations of functions, etc. All bike functions are really only on the top line - very hard to read when actually on the bike.

- the thing stops recording after about 15 or 20 minutes of no HRM. It says 30 minutes, but it is shorter than that. Under the 30 minutes, you should be able to make the thing "relearn" your chest transmitter - but there is a bug in the system that stops this ever working. After 30 minutes, the recording simply shuts down - you have no way of restarting it. You are meant to "Stop" and then restart the recording - but that never actually works either.

- there is NO ride distance function. Completely weird. There is a Trip function that records multipule rides, but as this is never reset, this cannot be used for ride distance.

- interference can be a REAL problem. This is not a real problem on the bike, but it can so muck up your recordings that it can be quite difficult to remove with the error correction software. I have done a few rides with averages around the 100+ kph.

- downloading to the PC can be hit and miss. The USB connection is prone to error and in fact I could never get mine to work so I had to revert to the Serial interface. Downloading can be very slow as you may have to retry 4 or 5 times before it finally all gets there.

While all this sounds pretty bad - the unit is actually fairly good overall, despite all the problems. I am quite happy with it. The software is really good - without that, I don't think I would ever have bought one. I just treat it as a"work in progress" - I am sure that Polar will resolve all of the problems in time.

You can reset the trip distance to zero. After you start your exercise, hold down the top left button for five seconds (the trip number blinks five times)...works every time.

Make sure you have the latest version of the software - much improved with merge exercise and block deletes. I use the infrared interface - very reliable.