As I've mentioned a few weeks back, I was the happy recipient of an excellent half century birthday present, in the shape of a Cervelo P3 frame and forks. I finally had the opportunity to ride it in anger a couple of days ago in the NBRC New Year's Day 10 mile time trial (reports at Flies&Bikes and at the NBRC website). How did it work out? Well first off, here's the specifications as assembled:

Part 3 - getting the GPS to work

My final posting on the Polar CS600X (probably) contains my observations on how to get the G3 GPS to send speed and track data the main unit.  These notes assume that the GPS has been "inroduced" to the CS600X.

1.  Navigate via Settings to the Bike menu.  scroll down beyond Bike 3 and select Other.  Turn this option on.

2.  Turn on the GPS by ressing the button once.  It will flash a red LED - this will turn green once contact has been made with the satellites.

3.  Don't set the main unit going until the GPS has made contact.  The main unit will probably say "Check Power" (click OK) and "Check Speed" (click OK).

4.  Set off riding the bike.  Your HR will be showing.  In my experience it takes around half a mile before a speed reading is shown, but after that things seem to work quite smoothly.

5.  I find it more convenient to put the GPS in  a jersey pocket than to strap it to my arm.

Review of the Polar CS600X with Power (Part 2 - using the GPS)

I have finally persuaded, by dint of actually reading the manual, managed to use the Polar G3 GPS unit to report speed/distance and the route to the CS600X.  Unfortunately, I'm not exactly sure what made the difference.  I think it was switching the GPS on before starting to record the exercise.  What with all the faffing around, I ended up only recording a few miles on a ride curtailed by rain.

The GPS unit only needs to be configured (or "introduced") to the main unit once.  You also need to select "Other" in the bike settings menu (oddly, you can't ever seem to deselect "Bike 1"). To use the device, you're supposed to strap it to your upper arm but I clipped it to one of the cables, so it hung a little in front of the handlebars.  You turn on the GPS by pressing its only button, after a bit of flashing of lights it seems to find the satellites.  But not before the computer's asked one to check the speed and power sensors (neither of which was actually fitted).

In use, I was comparing the reading to a conventional wired SigmaSport computer.  The speed readings seemed pretty comparable, but there was a definite lag to the GPS derived reading compared with the SigmaSport.  So, the jury's still out as to whether the Polar G3 GPS is realistically usable as a substitute for a speed sensor - I had hoped that forking out for the GPS would mean I could avoid having to buy speed sensors for the bike fleet.  Time will tell, I dare say.

Part 1 - initial impressions

I recently bought a Polar CS600X bike computer/HRM, with an associated Power meter system - here I present an initial review of the unit.  I later bought the add-on Polar G3 GPS unit for use with it - I'll review this separately as I haven't had a chance to use it at the time of writing.

Out of the box, the CS600X looks little different from any other modern bike computer - it's the usual streamlined shape with a large-ish display and several buttons.  Annoyingly mine came without the bike mount.  I suspect this was in error, but emailing the supplier elicited no response and I then left the country for a couple of weeks.  I ended up buying several bike mounts anyway, as I plan to use it with several bikes.  The unit is supplied with a speed sensor and the Polar W.I.N.D. power meter, which includes a cadence sensor.  As supplied, the CS600X has already been "introduced" to these transmitters - the introduction process seems to be one where the parts exchange identification code to prevent cross-talk between two cyclists.

Installing the speed sensor is simple - much like other wireless bike computer systems.  Since I decided I'd be using the system on my turbo trainer, I set this up on the rear wheel.  Entering the wheel/tyre diameter is nothing unusual, as is entering one's personal data.  And indeed, this can be done using the included Polar Protrainer software.

Installing the power system is a fair bit more complex, but not terribly hard for someone with reasonably good bike tinkering skills.  Essentially it's in two parts.  The simple part is the battery holder, which mounts on the right hand seat stay.  This connects to the main sensor unit on the chain stay by wire.  A second wire extends from the power sensor to the rear derailleur, where it attaches to a chain speed sensor.  Attaching that sensor is a bit fiddly, and requires replacing the jockey wheel bolt with one that has a thread to which the sensor screws.  This was the only real hitch, as my ancient Mirage mech seemed to have a strange bolt thread (or it was just badly corroded).  In the end the only usable rear mech that I had kicking around was a 9 speed Record one, which does seem a bit over-specified for a turbo trainer bike.

There are clearly stated instructions for positioning the power sensor on the chainstay - this needs to be positioned correctly fore and aft as well as with respect to how close it lies to the upper chain run.  However, this isn't particularly difficult, though it can be fiddly.  Finally, the cadence magnet is attached to the crank arm.

As best I can tell, the system works in a manner analagous to an electric guitar pickup, and you need to enter a bunch of data to do with the number of links, the chain weight and the BB to rear hub distance.  That would have been fine, but I was using a dirty old chain, so things got a bit messy!  I have no idea how accurate this system is - anecdote would suggest that it's less so that the more expensive offerings on the market.  I'm not particularly bothered whether 200W on this system really is 200W, but rather that the system is consistent and that values reported are proportionate to the real values.

Having set the thing up, it does look a little cumbersome, with wires looping around the place.  I'd be unhappy using it on a sleek time trial bike, and indeed I'd imagine it might be susceptible to damage when transporting the bike.

In use, the first problem I faced was scanning through the different displays, which emphasise just how much data are available from a computer like this.  Some of the screens seem unneccessarily complex to me, such as the default Power display, which has got all sorts of stuff like left-right pedalling balance and the altitude display, which includes inclinometer displays.  You can of course customise at least some of these displays, though the "Zone Lock" display, which usefully shows what training zone one's in and how long one's been there seems a little refractory to customising.  Unless, of course, I'm missing something.

I've been using this device for a week now, and have mostly been sorting out how best to use it, and such things as display customisation.  I would say that thus far I've used it for HR-based training only.  But on the other hand I'm getting a fix on what power I produce at a given intensity level (here I'm using a blurred perception-HRM derived idea of exertion level), and I am sure I will be able to use power values more appropriately as this winter's training proceeds.

The CS600X came with a USB IRDA device with which to download and upload data to and from a PC, using the supplied Polar ProTrainer software.  As far as I can see, there's definitely a PC version, and there doesn't seem to be a Mac or Linux (boo!) version.  The software seems to be pretty comprehensive, but the proof will be in the use, so watch for later parts of this review.

In the next part, I'll review the G3 GPS unit.  Assuming I actually get out on the road bike, which is not necessarily going to happen for a week or so, judging from my likely workload!  In later parts, I'll review it in actual use.  No doubt