Polar CS600 Power - First on the Block...



J-V

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Nov 3, 2003
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OK, OK, I know you guys will say I caved after that last thread, and I did (in a way). FedEx will be delivering (within the hour) PerformanceBike.com's only, single Polar CS600+Power that they've yet received. Two reasons I decided to live with it's quirks:

1) The current 10% online coupon (#6001753) in conjuction with being a Team Performance member brought the price down to $568, a bit more palatable.

2) The 'resolution switching' after an out-of-memory situation (although an inane solution to an easily-solved problem) at least allows completion of the ride, with data. Currently, the S720i just stops dead in its tracks.

I decided that for $200-300 more than the old power setup, it was worth it to bite the bullet. I've been riding in lots of wind lately, and it's incredibly difficult to gauge exertion in comparison to how poor I'm feeling at any given moment. But alas, I digress...

I saw the unit yesterday in my LBS, and luckily they weren't willing to budge much (5%) on price, so I checked with Performance.com, and they had only one in stock (wasn't yet on the website). I just checked, and it's now on the website, showing backordered ... :p

Anyway, as soon as it arrives, I'll immediately install it on my nice, newly washed (old) bike, and I'll report back with how it goes. Won't get a chance to ride it until Monday (sleet/snow at the moment, going skiing this weekend), but I'll certainly report back to this thread afterward. Let me know if you guys want any specific info or pictures. Unfortunately I'll run the new software on a mac pushing VirtualPC and W98, but I guess it's better than nothing!

Cross your fingers... :eek:

-J\V


backordered
 

Thom_y

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Aug 16, 2006
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Great news... I'm waiting to see some real world reviews on this thing. Do you have access to another powermeter so that you can review how the CS600 compares with some of the more expensive meters out there. I'm especially interested to hear how it works indoors on a fluid trainer (I have my 1992 Trek 5200 retiring on a Cycleops FLuid2). I have seen one posting comparing the CS600 Power unit to a Tacx Fortius ergometer (on Google Wattage group), but it seemed to have problems ... may have been interference from the electrical brake motor which has been described as a problem with the PT hub as well.

lawrence
 

J-V

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Nov 3, 2003
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Nope, I have a Cyclops Pro 300PT at home, so it will never see the light of day on a trainer (if I can help it). Haven't heard of any problems yet, but since so few have the unit, not sure how much stock I'd put into it...
 

J-V

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Nov 3, 2003
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Well, I got it installed (I think?) after some fussing with the Power sensor. Unfortunately, it would appear that this remains the achilles heel for installation, even though it probably only took about an 60-90 minutes total. Without being able to use the thing, it's hard to tell if it's currently set up correctly or not (it does indicate power readings, though haven't yet entered chain data). It was almost impossible to get set up perfectly parallel to the chain line (in any ring/cog configuration), as it would need to be angled in significantly toward the rear hub to be perfect, and I couldn't find a combination with the spacer pads that seemed to work. Also, the directions recommend a ridiculous 2mm space between the chain and power sensor when in the small/small, but the magnet in the sensor sucks the chain to it when closer than about 1/2 to 5/8". Seems like the power sensor is going to have to take a lot of abuse from the chain, and will suck down to it with any amount of slack. I have a feeling I'm going to have to revisit the alignment or spacing of this thing once I get on the bike to use it. :( [BTW if anyone has any links for installation tips of the previous unit, I have a feeling the same issues apply, and I'd be grateful for any further info on this.]

At first I thought all the 'slack' in the power cord (going to the pulley) in the small/small would be a problem, but it actually ended up working perfectly when completely zip-tied to the derailleur cable; it's much less conspicuous than I thought it would be, and naturally winds into a little circle that keeps it clear of the spokes. The battery 'cigar' is a bit of a bummer (visually), but oh well... The crank magnet is supposed to be secured with a goofy-lloking piece of Polar tape, but there's no way that's gonna happen. Not sure why they had to mess with their previous ziptie-able magnet, though this magnet is much heftier than any other cadence magnet I've ever used. Speed sensor is a no-brainer, works well, and is smaller than all previous versions.

Installation instructions are marginal at best, and the usage and features 'manual' (if you could even call it that) is positively pathetic. It really gives no info other than the basic setup stuff that is totally intuitive anyway, like height, weight, wheel data, etc. (my S720i at least came with a manual that described all the features and settings). I have a feeling I need to install the software to continue configuring it, but haven't done so yet. Unlike the S720i, there are apparently many setup functions only accessible from the computer. It doesn't even tell you what different 'views' are available on the display, even though it is supposedly somewhat customizable. It simply inane to expect us to go look something up on a computer every time we have a question, especially for a unit with this many features. The display is quite nice, higher resolution than the CS100/200 units.

Did I mention the new WearLink HR transmitter yet? It positively SUCKS!!! Why Polar had to go and 'improve upon' a perfectly functional transmitter design I have no idea. The snaps are ridiculous, since it's questionable as to whether you've got it properly secured. Furthermore, the way the EKG pickups (or whatever) are integrated into the strap now requires wetting with water prior to use. And I do mean WET. I need to find out if my T61 coded strap from the s720i will work or not, but it did not seem give an HR reading. This really is a step backward, all for the apparent convenience of self-changing a battery that only died every 2 years or so... :( If anyone has any other experience with this transmitter, please do share, because I'm not looking forward to using this thing.

Anyway, I guess I'm off to install the ProTrainer software and see what headway I can make with entering the chain data, and seeing what functions it has for power (display, etc.).
 

J-V

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Nov 3, 2003
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OK, so spending some more time with it, I did find the 'Display' settings menu, and where in the bike settings the chain data is entered. Oddly, a Dura-Ace chain is the default, so only needed to add axle to BB length. Display customization is pretty good, even though I'd like a computer to display five or six items at once... :)
 

Tom Anhalt

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Dec 9, 2003
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warnerjh said:
Well, I got it installed (I think?) after some fussing with the Power sensor. Unfortunately, it would appear that this remains the achilles heel for installation, even though it probably only took about an 60-90 minutes total. Without being able to use the thing, it's hard to tell if it's currently set up correctly or not (it does indicate power readings, though haven't yet entered chain data). It was almost impossible to get set up perfectly parallel to the chain line (in any ring/cog configuration), as it would need to be angled in significantly toward the rear hub to be perfect, and I couldn't find a combination with the spacer pads that seemed to work. Also, the directions recommend a ridiculous 2mm space between the chain and power sensor when in the small/small, but the magnet in the sensor sucks the chain to it when closer than about 1/2 to 5/8". Seems like the power sensor is going to have to take a lot of abuse from the chain, and will suck down to it with any amount of slack. I have a feeling I'm going to have to revisit the alignment or spacing of this thing once I get on the bike to use it. :( [BTW if anyone has any links for installation tips of the previous unit, I have a feeling the same issues apply, and I'd be grateful for any further info on this.]

At first I thought all the 'slack' in the power cord (going to the pulley) in the small/small would be a problem, but it actually ended up working perfectly when completely zip-tied to the derailleur cable; it's much less conspicuous than I thought it would be, and naturally winds into a little circle that keeps it clear of the spokes. The battery 'cigar' is a bit of a bummer (visually), but oh well... The crank magnet is supposed to be secured with a goofy-lloking piece of Polar tape, but there's no way that's gonna happen. Not sure why they had to mess with their previous ziptie-able magnet, though this magnet is much heftier than any other cadence magnet I've ever used. Speed sensor is a no-brainer, works well, and is smaller than all previous versions.

Installation instructions are marginal at best, and the usage and features 'manual' (if you could even call it that) is positively pathetic. It really gives no info other than the basic setup stuff that is totally intuitive anyway, like height, weight, wheel data, etc. (my S720i at least came with a manual that described all the features and settings). I have a feeling I need to install the software to continue configuring it, but haven't done so yet. Unlike the S720i, there are apparently many setup functions only accessible from the computer. It doesn't even tell you what different 'views' are available on the display, even though it is supposedly somewhat customizable. It simply inane to expect us to go look something up on a computer every time we have a question, especially for a unit with this many features. The display is quite nice, higher resolution than the CS100/200 units.

Did I mention the new WearLink HR transmitter yet? It positively SUCKS!!! Why Polar had to go and 'improve upon' a perfectly functional transmitter design I have no idea. The snaps are ridiculous, since it's questionable as to whether you've got it properly secured. Furthermore, the way the EKG pickups (or whatever) are integrated into the strap now requires wetting with water prior to use. And I do mean WET. I need to find out if my T61 coded strap from the s720i will work or not, but it did not seem give an HR reading. This really is a step backward, all for the apparent convenience of self-changing a battery that only died every 2 years or so... :( If anyone has any other experience with this transmitter, please do share, because I'm not looking forward to using this thing.

Anyway, I guess I'm off to install the ProTrainer software and see what headway I can make with entering the chain data, and seeing what functions it has for power (display, etc.).

OMG, it sounds like they didn't even get the new installation instructions updated properly. :rolleyes:

Here's a couple of tips on the setup based on my experience with the previous model:

1. The sensor module DOES NOT need to be parallel the the chain, in any sense of the word, in either a vertical or lateral direction...period. The actual "sensing element" in the module is an ~1 in. square inductive sensor centered on the "middle" mark of the case. ALL you need to do is make sure that the chain passes over this area of the module in all your gear combos, and that the chain is never vertically further than 25mm from the top of the case AT the "middle" mark. Does the new case still have a "middle" mark?

Basically, angle it however you need to fit it on and just worry about what I said above.

2. If you're trying to set a minimum space in the small-small combo, I think you're going about it backwards. On most bikes you won't be using that gear combo anyway. Don't worry about the space in the small-small combo, worry about the space in the largest big ring - large cog combo you use. See above.

3. Don't worry about "abuse" to the top of the module case, it's made out of some tough plastic and when you're pedaling, the chain tension will keep it off the case.

4. I glue my crank magnets (I use some very strong "rare earth" type magnets) to the crank arm using contact cement. They stay there forever.

5. Even though they have the DA chain as the "default" in the computer, ALWAYS, ALWAYS, ALWAYS physically weigh your particular chain. I can't emphasize this enough. In the last 3 years I've seen a stock DA 9 speed chain go from 304 grams (116 links) to 297g, to 290g on the last set of chains I replaced. Every percent error in chain weight corresponds to the SAME percent error in the power calculation. If I was still using the original DA chain weight, I would think my FTP was 15W higher than it actually is!!

WEIGH THE CHAIN!

6. An accurate measurement of the chainstay length is also important since this factor is SQUARED in the power calculation. Take careful measurements here too.

Hope that helps! Any chance you could borrow a friend's turbo or fluid trainer and do a constant speed sweep through the gears (min. 2-3 minutes in each gear) and then look at the average powers over those sections?

Tom
 

J-V

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Nov 3, 2003
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Hey Tom, thanks for replyiing. I finally got into the User Manual (only online and on CD), and they sure have this bass-ackwards! The intallation manuals you presumably use once; they give you paper copies of those. The User Manual one might use several times a week for the first 6 months of use; no, no, paper would be too easy, you get an electronic version of that one...

Anyway, in response:

1) Great, that helps a lot. Yes, it has a middle 'dot', with sort of hash marks extending another 3/4 out. That thing sure sucks the chain down!

2) So max of 25mm in the large-large, regardless of whether it's rubbing in the small-small. I noticed that the two versions of the sseveral page (older installation manual) give two completely different minimum clearances when adjusting it to the small-small (one says 5-10mm, the other 10-30mm). \eyeroll/

3) Good to hear. I thought about putting two zip ties around the case so the chain rubbed on those instead. I assume there's no reason I can't do this, as long as they aren't over the 1x1" square?

4) Good idea. Their Polar logo tape idea is ridiculously, hideously, atrociously ugly. :)

5) They say in the manual that it's chain density that matters, and thus it's only the weight in concert with the length that matters? In other words, the actual length doesn't need to be accurately input for it's calculations, as long as it's weight is correct for the entered length (I find this odd, but if it's only using density, it makes sense). I guess older chains could be lighter, and I guess I'll bite the bullet and remove it (even though it only has 500 miles on it). The problem is that I doubt I have a scale accurate enough that it would be any better...

6) Got the chainstay length down pretty accurately, but I will triple-check it on your advice.

Actually, I have a low-end Blackburn Fluid Trainer (the blue one), though don't know anyone who has one with power integrated into it. Do you need to hold a constant speed? Because I mounted the speed sensor on the front wheel, although I guess there's no reason I couldn't have mounted it on the chainstay. It doesn't list any max distances from the computer.

Now that I've read through the manual thoroughly, it actually is pretty cool, though lacking in some power tracking numbers. It will give you average power for an interval (a set of laps), but not sure if you can see this until after. It appears to have a dedicated cadence 'box', so you can actually see FOUR ride metrics at once; very, very cool. The different display pages are pretty much completely customizable, which is my task for tonight. It shows your HR in one of 5 zones, it's too bad they didn't configure this to allow them to be power zones.

Anyway, I'll be back Sunday night, and try to weigh the chain and test it all out...

Thanks,

J\V
 

jstock

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Apr 24, 2006
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warnerjh said:
Anyway, I'll be back Sunday night, and try to weigh the chain and test it all out...
Make sure the connectors are attached well before you ride. Did my fourth (real) ride today with the cs600 and one of the connectors came loose.
 

Tom Anhalt

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Dec 9, 2003
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warnerjh said:
1) Great, that helps a lot. Yes, it has a middle 'dot', with sort of hash marks extending another 3/4 out. That thing sure sucks the chain down!

Yep...that's because the "core" of the inductive sensor is magnetized and your chain is steel. Like I said, that attraction is a non-issue with a tensioned chain.

warnerjh said:
2) So max of 25mm in the large-large, regardless of whether it's rubbing in the small-small. I noticed that the two versions of the sseveral page (older installation manual) give two completely different minimum clearances when adjusting it to the small-small (one says 5-10mm, the other 10-30mm). \eyeroll/

Yeah...the Polar official "instructions" have always been a bit "off"...I don't know if it's a translation thing or what. I got my info (don't worry about the close gap, worry about the far gap) direct from one of the inventors/developers of the device. I think I'll listen to him ;)

warnerjh said:
3) Good to hear. I thought about putting two zip ties around the case so the chain rubbed on those instead. I assume there's no reason I can't do this, as long as they aren't over the 1x1" square?

Naah...you can put them over the "square"...but they'll just rub sooner. That's where I had mine at one time. But, like I said, after awhile I realized that they weren't really necessary. The case really doesn't wear in any significant manner at all.

warnerjh said:
4) Good idea. Their Polar logo tape idea is ridiculously, hideously, atrociously ugly. :)

Oh...but it says "Polar" all over it... :D

warnerjh said:
5) They say in the manual that it's chain density that matters, and thus it's only the weight in concert with the length that matters? In other words, the actual length doesn't need to be accurately input for it's calculations, as long as it's weight is correct for the entered length (I find this odd, but if it's only using density, it makes sense). I guess older chains could be lighter, and I guess I'll bite the bullet and remove it (even though it only has 500 miles on it). The problem is that I doubt I have a scale accurate enough that it would be any better...

Yes...the "chain density" (i.e. mass per unit length) is what the computer needs to calculate the tension from the vibration frequency. I ALWAYS just enter in the chain weight for a 116 link chain length (1473mm) since a brand new chain is typically that length. Makes thing simple, especially if you adjust the chain length at a later time. Plus, it allowed me to quickly see that the new chains I had bought were a different weight! :eek:
Oh yeah...for a scale, I picked one up at the local office supply store for ~$25 and it weighs down to a resolution of 1 gram. A bonus is I can also use to satisfy any "weight weenie" leanings I may have as well ;)

warnerjh said:
Actually, I have a low-end Blackburn Fluid Trainer (the blue one), though don't know anyone who has one with power integrated into it. Do you need to hold a constant speed? Because I mounted the speed sensor on the front wheel, although I guess there's no reason I couldn't have mounted it on the chainstay. It doesn't list any max distances from the computer.

Move the speed sensor to the rear wheel and then just do a "constant speed" test through the gears. A constant wheel speed should be a constant (relatively...apparently some fluid trainers can "drift" as they warm up over time) power exercise. Just warm the trainer up for at least 10 minutes and then pick a wheel speed that allows you to have reasonable cadences through the whole gear range you want to look at. Obviously, some gear combos are going to be very light pressure (small ring - large cog) and relatively high cadences and at the other extreme you need very low cadences and relatively high pedal pressure (big ring - small cog).

This is how I first checked out my original Polar on a trainer. The "gear by gear" variations were pretty obvious.

The main reason I'd like to see if you can do it is to either confirm or refute that Polar made any changes to address this nearly fatal shortcoming in their product. Not getting this right doesn't greatly affect someone like myself who is lucky enough to be able to train outdoors year-round...but it's a definite "deal breaker" for someone who lives someplace with less benign weather conditions. Like I said in another posting, they had over 4 years to investigate and address this shortcoming...if they did nothing to change it, that would easily qualify the Polar product development folks as the biggest boneheads in power meter history :rolleyes:
 

J-V

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Nov 3, 2003
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Tom Anhalt said:
The main reason I'd like to see if you can do it is to either confirm or refute that Polar made any changes to address this nearly fatal shortcoming in their product. Not getting this right doesn't greatly affect someone like myself who is lucky enough to be able to train outdoors year-round...but it's a definite "deal breaker" for someone who lives someplace with less benign weather conditions. Like I said in another posting, they had over 4 years to investigate and address this shortcoming...if they did nothing to change it, that would easily qualify the Polar product development folks as the biggest boneheads in power meter history :rolleyes:

Tom, just out of curiosity, which 'nearly fatal shortcoming' do you refer to?

I just re-did the sensor and added an extra pad in the front (low side of the chainstay), and put the largest at the rear. It's still 1.5cm from the sensor in the small-small, and 4.3cm in the large-large. Rode it on the trainer for a bit, and the small chainring gears appear to work. The large chainring, however, is a different story. About 3 or 4 gears from the 27, it is clearly giving erroneous readings (on the high side). When I got off the bike and measured it, the chain was 3.2cm from the sensor. When it was 30mm or less, it appears to work, but that's just by 'feel'. It would seem that if it is more accurate the closer it is to the chain, that there would always be some margin of error. Seems odd that at >30mm there would all of a sudden be an error.

My bike is pretty typical, and it would be a bummer if most installations would require raising the power sensor off the chainstay by 2-3cm. They really need to provide a better selection of riser pads with significantly more thickness than these offer if that's the case. I'd be curious to see others' installations in both extreme ring-cog combos.

Guess I'll have to try to 'rig' something better tomorrow... :(
 

Tom Anhalt

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Dec 9, 2003
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warnerjh said:
Tom, just out of curiosity, which 'nearly fatal shortcoming' do you refer to?

I'm referring to the tendency to get "flakey" performance when run on an indoor trainer. For folks that want to train indoors with/by power, that's a "fatal shortcoming" and they're going to buy something else.

warnerjh said:
I just re-did the sensor and added an extra pad in the front (low side of the chainstay), and put the largest at the rear. It's still 1.5cm from the sensor in the small-small, and 4.3cm in the large-large. Rode it on the trainer for a bit, and the small chainring gears appear to work. The large chainring, however, is a different story. About 3 or 4 gears from the 27, it is clearly giving erroneous readings (on the high side). When I got off the bike and measured it, the chain was 3.2cm from the sensor. When it was 30mm or less, it appears to work, but that's just by 'feel'. It would seem that if it is more accurate the closer it is to the chain, that there would always be some margin of error. Seems odd that at >30mm there would all of a sudden be an error.

No...it's not that odd. What the sensor is "looking" for is "pulses" of steel causing changes in the magnetic properties of the inductive sensor. Normally, the strongest signal is from the chain vibrating. However, if the chain is further away, the vibration signal is weaker. Making this worse on a trainer is that there isn't the random road vibration input to the chain to cause it to vibrate at a larger amplitude. When this occurs, the signal processing circuitry may "lock on" to another "pulsing" signal, such as the pins of the chain itself passing the sensor, and mistake that for the vibration signal. This can cause erroneous power readings.

Basically, low tension, high cadence, smooth conditions are the worst for this device.

IMO, you need to get the module closer to the chain if you want reliable readings, even on the road. Like I said before, I set my units up so that they are NEVER further than 25mm from the chain. I started doing this after having the power reading just "go away" when I'd shift into my largest big ring-big cog combo when the module was set at 30mm. It was kind of annoying...

warnerjh said:
My bike is pretty typical, and it would be a bummer if most installations would require raising the power sensor off the chainstay by 2-3cm. They really need to provide a better selection of riser pads with significantly more thickness than these offer if that's the case. I'd be curious to see others' installations in both extreme ring-cog combos.

Guess I'll have to try to 'rig' something better tomorrow... :(

You've got to do what you've got to do :)

Most of my setups with "straight" chainstays have required about that amount of spacers (2 to 3 cms). My current setup has a "shaped" chainstay that has a convenient bulge right where I mount the module. On that unit, I merely have a small piece of cork bar tape stuck beneath it to prevent slipping. But...every setup is different.

I once even attached a Polar power module to the UNDERSIDE of a raised chainstay full-suspension MTB. It took a bunch of spacers on the TOP of the module...and the chain was sensed from below. I still kept the spacing at 25mm from the case, but the bottom of the case ;)

It actually worked really well that way :D
 

J-V

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Nov 3, 2003
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Tom Anhalt said:
Like I said before, I set my units up so that they are NEVER further than 25mm from the chain. I started doing this after having the power reading just "go away" when I'd shift into my largest big ring-big cog combo when the module was set at 30mm. It was kind of annoying...

You've got to do what you've got to do :)

Most of my setups with "straight" chainstays have required about that amount of spacers (2 to 3 cms).

OK, It tried to re-work it with some thick foam from a very old Accurex II mount, but that didn't work. Not finding anything in the garage, I went back to the 3 sets of pads included with the unit, and used the two largest sets 'reversed' on each other in order to get the spacing down to 6mm and 36mm, respectively. Obviously I'll never get to 25mm (you must be running a smaller cogset in the rear?) with a 53/39 and 12-27. I think I'll try it here, and see how it goes.

I may try to set it up on the Blackburn fluid trainer tonight, but I still need to troubleshoot the download part of it before I could get you a file to check out. The new ProTrainer software apparently isn't made for W98, and the first time I tried it it crashed about 5 minutes into it. Hopefully the recent PPP update (v. 4.03.044) includes support for the CS600, so I'll try updating that tonight and see if I can get the data off from today's ride (pre-tweak).
 

J-V

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Nov 3, 2003
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OK, here's a few pictures. The first is from the latest install, the second side view is from the initial install (which was too far from the chain). Haven't yet ridden the raised version, and once I figure out how to get the IR working, I'll put it on a trainer and run through the gears. At the moment yesterday's ride data is stuck on there...
 

Tom Anhalt

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Dec 9, 2003
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warnerjh said:
OK, here's a few pictures. The first is from the latest install, the second side view is from the initial install (which was too far from the chain). Haven't yet ridden the raised version, and once I figure out how to get the IR working, I'll put it on a trainer and run through the gears. At the moment yesterday's ride data is stuck on there...

Aahh...here's a question for you: Where do you have the cadence magnet mounted on your crank arm? I can't tell from the pics exactly, but judging from the position of the module, it looks like you may have it midway or so on the crankarm, is that right? If so, I'd suggest moving it out close to the pedal spindle. In fact, some folks attach a circular magnet to the end of the pedal spindle itself. That works great with a steel spindle since the magnet holds itself in place.

Moving the magnet to that location will allow you to move it further back on the chainstay and reduce the amount of shimming required to get a good chain distance measurement.

Hope that helps....

Tom

Edit: Oh yeah...My setup is 25mm max spacing for a 53/39 crank and 12-27 cogset (but I mostly run a 12-25).
 

jstock

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Apr 24, 2006
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Tom Anhalt said:
Aahh...here's a question for you: Where do you have the cadence magnet mounted on your crank arm? I can't tell from the pics exactly, but judging from the position of the module, it looks like you may have it midway or so on the crankarm, is that right?
Maybe warnerjh trusted the manual? It says that you must mount the sensor exactly in the middle of the chainstay. But if I recall correctly this is not the case.

Speaking of magnet placement, on one bike I have a rare earth magnet on the spindle. I do have one problem with it. When soft pedaling in the big ring the magnet can pull the chain and RD which will give readings of over 300 watts.
eek.gif
 

J-V

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Nov 3, 2003
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Tom, my magnet is mounted maybe an inch from the pedal axle, and I haven't had a problems with it that I can tell. That would only give another 3/4" or so to move it back, assuming I keep it inside the pedal axle (which I'd like to do).

jstock said:
Maybe warnerjh trusted the manual? It says that you must mount the sensor exactly in the middle of the chainstay. But if I recall correctly this is not the case.

Yes, I did follow the directions and mount it exactly in the center, since they seemed to make a point of doing so. It certainly would be more convenient to simply move the sensor rearward to achieve the same effect, if the collective 'we' are sure that it does not matter. Still, even if the chain is just rubbing in the small-small, I'm still right at 30mm difference on the opposite end. I'm more likely to get close to the small-small while riding than the large-large. I hate to get into a situation where I'm avoiding previously usable gears for the purposes of generating 'good' data; I'd say that falls into the 'failure' category. :)

'jstock' have you had luck downloading the data via IR? I didn't expect to have a problem since my 720 works, but I guess I should perform a 'reset' before troubleshooting much further.

J\V
 

Tom Anhalt

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Dec 9, 2003
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warnerjh said:
Tom, my magnet is mounted maybe an inch from the pedal axle, and I haven't had a problems with it that I can tell. That would only give another 3/4" or so to move it back, assuming I keep it inside the pedal axle (which I'd like to do).

Why would you like to keep it inside the pedal axle? Just curious.

My magnet is bonded to the side of my crankarm even with the pedal spindle. Moving the module back a full inch will make it easier to achieve the proper chain spacing AND bring the cadence sensor closer to the magnet since the module will be moving outboard as well along the chainstay (because of the angle of the chainstay relative to the bike centerline).


warnerjh said:
Yes, I did follow the directions and mount it exactly in the center, since they seemed to make a point of doing so. It certainly would be more convenient to simply move the sensor rearward to achieve the same effect, if the collective 'we' are sure that it does not matter.

Well...I'm not a "collective 'we' "...but I say that it doesn't matter...and I've confirmed this with the inventors of the system. The only reason to try to get the sensor located at the center of the chain span is that this is were the chain vibration amplitude is the greatest. However, if locating it there results in the chain being too far away, that's not helping any. The amplitude of the chain vibration a couple of inches to either side of the center is not going to be reduced by an great amounts...and we're not talking about large amplitudes here anyway. So, it makes a lot more sense to just locate the module where it's close enough to the chain to ensure an adequate signal...center of the stay be damned ;)

I present this "requirement" in the Polar manual as further evidence that the technical folks at Polar TRULY do not understand their own device :rolleyes:

warnerjh said:
Still, even if the chain is just rubbing in the small-small, I'm still right at 30mm difference on the opposite end. I'm more likely to get close to the small-small while riding than the large-large. I hate to get into a situation where I'm avoiding previously usable gears for the purposes of generating 'good' data; I'd say that falls into the 'failure' category. :)

Do you really use the small-small combo gearing? I know that on my bikes it either causes the chain to "tink" on the teeth of the large chainring or rub the front derailluer cage if I try to use my 2 smallest cogs with my small chainring.

Similar problems exist with my 1 or 2 largest cogs and my large chainring. Perhaps my bikes tend to have relatively short chainstays which would make this problem worse, but my main roadbike's chainstay is on the order of 412mm or so, IIRC, which isn't _that_ short.

Here's an idea for you. On one setup of mine that has <400mm long chainstays, I set up the maximum chain spacing so that it was measured in the large chainring - 2nd to largest cog. I did this because on that bike I'd NEVER use the large-large combo do to the extreme nature of the cross-chaining caused by the relatively short stays. Do you use the 53-27 very often, if at all? If not, that could be a compromise you may want to consider.

I've got some pics around of my setup when it was on my Cervelo Soloist. I'll see if I can post them tonight. Perhaps I'll take some new one's of how my module is mounted on my other road bike (Kona Zing Supreme) as well...that may help you see how I put mine together. 3+ years of reliable power readings say that I'm doing *something* right :D
 

Pelotonium

New Member
Apr 2, 2007
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Tom, you seem to know what you're talking about. I've worked very hard to get my PPO unit to work consistently, to no avail.

May I ask where you got your magnets, and what glue you used to bond them?
 

J-V

New Member
Nov 3, 2003
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As far as the crank goes, I'd just like to keep it away from possible contact with anything, and outside the pedal spindle axis seems a bit more 'exposed'. No other reason.

All my gear combos are usable (no rubbing, still have some range of motion), and I don't really use the small-small, although I have for very brief periods. The 53-27 I do not (and will not) use, so I guess I sort of have disregarded it in reference to setting this thing up, even though I quoted the 30mm spacing based upon that gear.
 

jstock

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Apr 24, 2006
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warnerjh said:
'jstock' have you had luck downloading the data via IR? I didn't expect to have a problem since my 720 works, but I guess I should perform a 'reset' before troubleshooting much further.
It works for me. Are you using builtin IRDA or a Polar USB dongle? I actually did some extensive testing to see whether I could get it to work directly with WKO. My results:
S720 works with both builtin IRDA and the S-series dongle for both the Polar software and WKO.
CS600 works with the Polar software with builtin IRDA. S-series dongle does not work (it's not supposed to work, but someone forced me to try it:)).

A stupid question maybe, but have you looked at your CS600 to see where the IR port is?

But there is something strange going on. When I disconnect the device, XP still says it's connected for several minutes and the computer becomes sluggish (this does not happen with the S720). But it does work.


Tom Anhalt said:
I present this "requirement" in the Polar manual as further evidence that the technical folks at Polar TRULY do not understand their own device
Actually I don't think it was in the manual, but on a separate note ;)