Polar CS600 Power - First on the Block...

vadiver

What is the issue witht the PT/Fortius?

Tom Anhalt

Well...to me it's more of a "preference" than anything else. After >3 years of having altitude data for my rides, I'm pretty much just used to having it. In fact, after downloading my power files into CyclingPeaks, typically THE FIRST trace I display (the power trace is displayed automatically) is the altitude trace...especially if it's a ride I haven't done before. It really puts the power trace "in perspective" IMHO.

I don't mean to turn this into a "PT bashing" thread (although I guess I would be allowed since I own one of those too), but besides the lack of altitude, one other thing that I have an issue with the PT is that it's measuring the power that gets to the road, i.e. after the driveline losses. IME, these losses can be highly variable depending on chain condition (up to 5 to 10W) and according to published studies, can vary widely just from gear to gear.

Here's my experience from earlier in the year when I was running the PT in conjunction with my Polar on the same bike:

http://biketechreview.com/phpBB2/viewtopic.php?t=1370

The problem is that if you're using the PM to monitor the "engine", having the measurement point be so far "downstream" can give you false readings on what you're interested in. Conversely, if you're interested in doing field testing of TT positions, the PT would be the best thing to use...which is why mine resides on my TT bike



Oh, c'mon...how often does THAT happen? My experience with the Polar altimeter (barometric sensor) is that it is reasonably accurate, even during long rides. It does tend to vary from day to day, but that's why there's a "home altitude reset" you can easily perform before starting out.

vadiver

I keep bouncing between SRM and PowerTap (I think the strain gauge is the way to go IMO). I really like my Campy ergonomics over the Shimano so I am planning on converting my Shimano to Campy as needed. If SRM had an UT style crank (other than DA) that is the route I would go.

I agree with the Altitude issue. It is a "like" but that is ok for me. I am fighting with how important is it really.

My comment about being cool to plot but worthless othewise was just for that one ride. Not all of the rides.

I have only had the one really bad front move in. I did not really care but it sure looks inpressive being able to climb a massive hill at 20-25 MPH. But there are still quite a bit of differences in starting altitude and ending altitude after as short as 1 hour of riding. Not a bash at all, I live with it. I leave my house at 278 feet and get back at 200 or 350 depending on how long I ride.

Tom Anhalt

I believe they have an FSA crank version with the outboard bearings as well.



Yes...if the choice is between good and adequate power data vs. altitude, the altitude will lose every time. But if you can have BOTH?? That would only be better.

One thing that some of the analysis software (such as CP) could take advantage of in the future is dynamic modification of FTP based on altitude. Of course, that would mostly be useful for folks living in highly mountainous regions.




Hmmm...what unit is this? It sounds as if the it's altitude sensor may not be temperature compensated. I can go on multi-hour rides, with 10-15 degrees F of temperature change, and have the Polar altitude reading at the end be within 10-20 ft. of the starting value. That's actually not so bad....

Besides, the more important values to me are actually the CHANGES in altitude over ride segments, rather than the absolute value. For those measurements, I find the barometric function to be more than adequate.

J\V

I have been using altitude since the Avocet 50 days, the very first (IIRC) cycling altimeter. If you live in a very flat area, I could see how tracking the number of feet climbed might be superfluous. In regard to the question of 'how important is altitude?', I would ask this: What is the primary cause of speed fluctuations during riding? Answer: gradient. Considering how quickly and dramatically road gradient can change, it is much more important than wind, road surface, position on the bike, etc. So, given this fact, why would we so easily ignore it as a metric to be tracked, along with power, speed, cadence, etc.?

FWIW, my Polar is usually within about 20' at the end of a ride. There is no accommodating slight atmospheric pressure fluctuations while on a (relatively) short bicycle ride. While flying in aircraft, we go longer distances, have radios to update our data, etc., not realistic for cycling. The number of times I've ridden through a front that affected the data I can count on one hand. Usually such times are so windy, you really don't want to be on your bike, anyway (kind of like today, here). Barometric pressure fluctuations are (in the grand scheme of things) relatively minor, and when you consider that the technology for collecting altitude data has been in the consumer cycling realm for nearly 15 years, it's pitiful that everyone hasn't included it on nearly every cycle computer costing more than $75, let alone a $1000+ power meter. (PowerTap's 'virtual cadence' is another complete joke that has hopefully been corrected in the newest versions)

I'm also not here to bash the PowerTap or any other technology currently on the market, and I fully realize that anyone using another one of the products would be less than impressed by Polar's approach, even though it is admittedly the most cost-effective of all the designs that actually measure something power-related. I can't justify spending $1500 to $3000 on my 14 year old steed, and when I finally get my $5500 wonder bike in the next year or two, hopefully either PowerTap or Ergomo will have solved some of the issues that currently remain.

Respectfully,

J\V

__________________

'07 S-Works Tarmac SL, Polar CS600+Power
2008 Cervelo P3C, Zipp 808s

'07 Specialized Epic Marathon w/Crossmax SLRs
CycleOps Pro 300PT Indoor Cycle Trainer (my winter ride)

Pelotonium

It actually happens quite often on long rides. I ride on a F1 track with relatively no altitude change ( < 15m ), and yet I often see a gradual creep corresponding to 150m or more during a 3hr ride.

I know 150m isn't much, but barometric pressure is not a great way to measure altitude.

Tom Anhalt

Huh? 150m over a 3 hour ride? What unit is that? I want to know what to stay away from...

That's easily an order of magnitude larger than anything I've ever seen over 3-5 hr. rides with the Polar.

vadiver

I agree. I think my original post sounded too critical, sorry for that. All of my altitude profiles "look" the same on my regular routes. Unless a person does a point by point comparison (why would they for these purposes) one would not tell the difference.

The one that stands out was weird. It was supposed to be a lousy day for riding. I went out side and it was fine (no wind even) so I went for a ride. I felt the weather change and turned around. When I loaded the data I thought that was pretty cool.

I agree about not including it on a cyclocomputer. I have it on a $75 watch so it cannot cost that much to put on/in. And barometric pressure is just fine.

I agree on the cadence issue as well. I would be putting on the cadence censor to get away from the derived cadence. I have a derived power output on my CicloSport 436 and that is for the most part, pointless. Particularly on a download.


Again, I agree. I looked at polar when I first got started and almost went with it. I just did not think I would get into riding this competively (Knowing my personality I should have know better.) So I made a concious deceision not to go with a PM. Today, I regret that decesion.

Out of all the non-straingauge units available, I think the polar is the best way to go. IMHO.

I really appriciate you starting this thread. It will be very interesting to see how this works once you get to start using it. With luck the weather will clear and you will get some good rides and continue to report how things are going.

J\V

Unfortunately, it's the only way to measure altitude, other than using GPS. 'Measurements' in the vertical dimension using consumer-level GPS units can also be fraught with errors, much more so than the horizontal measurements. 10 years from now we might be having our cake and eating it, too, but we're not there yet (especially in regard to size/portability).

__________________

'07 S-Works Tarmac SL, Polar CS600+Power
2008 Cervelo P3C, Zipp 808s

'07 Specialized Epic Marathon w/Crossmax SLRs
CycleOps Pro 300PT Indoor Cycle Trainer (my winter ride)

J\V

The winds are supposed to calm later in the day (right now they are trending 10-40 mph), and I really want to get up my local 'TT climb' route. The immediate problem I now need to solve (soon!) is not being able to download the dang data! I'm set to '5s' mode until then, and the hours are ticking down...

I'm not going to bother with the trainer test until I know I can get the data to you guys...

J\V

__________________

'07 S-Works Tarmac SL, Polar CS600+Power
2008 Cervelo P3C, Zipp 808s

'07 Specialized Epic Marathon w/Crossmax SLRs
CycleOps Pro 300PT Indoor Cycle Trainer (my winter ride)

J\V

Thinking more about this, either:

1) Your altimeter isn't temperature-compensated and the temperature is changing during your relatively 'static' rides, or

2) You always ride during major frontal passages (your numbers equate to a 0.5" Hg change in three hours; the weather would be impressive), or lastly

3) Your altimeter is faulty, needs a new battery, etc.

I say #1 or #3.

__________________

'07 S-Works Tarmac SL, Polar CS600+Power
2008 Cervelo P3C, Zipp 808s

'07 Specialized Epic Marathon w/Crossmax SLRs
CycleOps Pro 300PT Indoor Cycle Trainer (my winter ride)

jstock

I really don't know much about it. It seems that most, but not all, PT users experience massive drop outs. Tacx acknowledged that there was a problem and that they were working on a fix. Haven't heard anything after that.
/J .

J\V

duplicate post deleted

__________________

'07 S-Works Tarmac SL, Polar CS600+Power
2008 Cervelo P3C, Zipp 808s

'07 Specialized Epic Marathon w/Crossmax SLRs
CycleOps Pro 300PT Indoor Cycle Trainer (my winter ride)

J\V

I just spoke with Polar Tech Support (term used loosely), and they indicate that (as 'jstock' reported above) the CS600 is no longer compatible with the previous Polar Serial>Serial-USB adapter hack. Only the silver v2.0 USB Adapter is supported, however he did unequivocally state that any third-party IRDa USB adapter should work just as well. Thankfully!

Off to OfficeMax to find out...

[Also, a quick FYI for other CS600 users, the 'timeout period' before the ride will cancel itself is apparently 30 minutes. Drink that Starbuck's quickly, or merge the data files later...]

__________________

'07 S-Works Tarmac SL, Polar CS600+Power
2008 Cervelo P3C, Zipp 808s

'07 Specialized Epic Marathon w/Crossmax SLRs
CycleOps Pro 300PT Indoor Cycle Trainer (my winter ride)