So I got a Polar power meter for Christmas, and I’m totally psyched. There was no way I could afford the >$1k powermeters, and I hadn’t been able to decide whether the cheaper price of the Polar would be more than offset by the problems some people appear to have with it. (I don’t care too much about the accuracy - 5% is good enough for me). Santa (aka my wife) ended up making the decision for me.
This post is essentially a public service for future STers searching the archives. I had found a few anecdotal reports of successes & failures with the Polar power sensor, but only a few. I really had no idea whether to expect it to work well or not. So I’ll add my experience to the archives.
For the record: I had no problems setting it up. The install did take me over 3 hours, but I have the mechanical skills of a sea slug. Seriously: I just learned how to adjust my derailleurs last week. I’d have taken it to the bike shop to install, but they were closed on Christmas and I was eager to play with my new toy. Everything went fairly smoothly, so it was not a stressful 3 hours at all. It appears to fit my frame (Felt F90) just fine, which is one of the problems some people have had.
It worked just fine from the start. After a few shakedown rides and one real ride, I have had no problems so far with signal pickup.
Two pieces of advice for anyone else installing one:
The instructions say that a yellow light should flash when the chain is moving. I get the red & green flashes for crank & wheel magnets, but no yellow flashes at all. But it appears to work fine anyway.
Pay careful attention to make sure the watch contacts the pins on the bike mount. Unless the watch is strapped down super tight, the connection can be loose. Plus the contact spots on my watch had “salted” over after 2 years of sweating on it, and I had to scrape them clean to get a good contact.
I had one too for about a year before I got my Powertap. I didn’t have the first major problem out of it. Install is fine if you take your time, and when side by side, it was maybe 10 watts at the most, off my Powertap through every gear but the 25, where it was more like 25 watts off. The biggest thing is reproduceability, i.e. your LT at 250watts is the same day in and day out on that particular meter.
I think it is a decent option if you already own a Polar watch and want to get into power training.
I agree. I already had a compatible Polar watch (625X) and couldn’t come close to realizing the money a ‘real’ power meter would cost so jumped at a cheap deal on a Polar power sensor. I also spent around 3 hours getting it set up and working, but since then (2 months now) I’ve had no problems. Compared to no power sensor it is great, and it allows me to reproduce specific efforts irrespective of how I’m feeling or the environmental conditions. The numbers tend to jump around quite a bit (say I’m aiming for 250W and start pedalling at a certain intensity that gets me to that number fairly consistently; the display will jump from 205W to 295W in a sort of bell curve around 250W) so it isn’t much good for instant feedback (how hard am I pedalling right now, or what is my left-right efficiency right now), but it is certainly good enough to execute on my training plan and to objectively gauge and/or limit my effort in a race situation. I’m sure an Ergomo or PowerTap would be more accurate and provide better real-time numbers but that will have to wait until my student loans are paid off.
The biggest hassle in using the same watch for bike and run functions at the end of the bike ride having to remove it from the bike mount, put the watch on your wrist, stop the exercise file, go to the functions menu and change the speed sensor from bike to run, and then start a new exercise file for the run, plus everything else that you do in transition 2. Of course, if you don’t care about using the run speed sensor, and in a goal race I don’t, then all you have to do is remove the watch from the bike and put it on your wrist - adds about 15 seconds before you can hand-off your bike after dismount. Or, take the watch off the bike before getting to the dismount line. Just don’t drop it during transition before you can fasten it on your wrist.
I had one that worked quite well, then a few years ago I started training with Powercranks, something about the wider Q angle and it now wont work properely. The crank magnet is just too far away. It collects dust now. Oh well.
I had one that worked quite well, then a few years ago I started training with Powercranks, something about the wider Q angle and it now wont work properely. The crank magnet is just too far away. It collects dust now. Oh well.
Why don’t you just shim the magnet a little closer to the pick-up? In most cases the Q of the PC’s is almost identical to what you had before so it shouldn’t take much. Also, another problem is the magnet should be a little off center for best pick-up. Try it again. You should be able to get it to work without too much difficulty.
I had one that worked quite well, then a few years ago I started training with Powercranks, something about the wider Q angle and it now wont work properely. The crank magnet is just too far away. It collects dust now. Oh well.
How much do you want for that dusty unit?
It also had something to do with the short chainstays, just couldnt get the adjustment just right. It would work fine on a bike repair stand, then on the road would only work intermittantly. Just got tired of trying to find the right spot to get it to work consistantly with the PC’s.
I would take a hundred for it. It shouldnt be all that dusty. I wrapped it up in a plastic baggie, and placed it in a box to protect it. I havent checked it in a while. I will check to make sure the batteries are still good, and if I still have the crank magnet around. If you are interested.
I have had on-going problems with the contact points. I tried to clean them up with some methylated spirits but to no avail. What did you use to scrape the contacts clean?
I thought it seemed a little “jumpy”, too. I’d pedal at a steady effort, and the watts would jump around a bit. But it seemed to settle down to fluctuations of +/-10 or so after a bit, so I figured it was just a smoothing thing. Is there a way to display average power rather than instantaneous power, or change the smoothing options (before uploading)? Does the jumpiness decrease if I set it for 15 sec resolution instead of 5 sec?
Isn’t your chain going to collide even worse with the receiver when you’re in your small front chainring?
Mine just misses touching when I’m in the small/small combination (unused gear combination, but puts chain nearest to receiver), and is pushing close to the max 30 mm recommended distance in the gears that put the chain farthest from the receiver. (I have a triple chainring with 8 cogs in back.)
Isn’t your chain going to collide even worse with the receiver when you’re in your small front chainring?
Mine just misses touching when I’m in the small/small combination (unused gear combination, but puts chain nearest to receiver), and is pushing close to the max 30 mm recommended distance in the gears that put the chain farthest from the receiver. (I have a triple chainring with 8 cogs in back.)
I haven’t done a full test to ensure consistency across usable gears yet, but I think it’s the closest i’ve come to the ideal setup. The chain just barely clears the sensor when in 39/12, and is otherwise in the 3cm range an all other usable gears.
Also, surprisingly, I get pretty accurate measures on a trainer, which I understood to be among the limitations of the Polar.