8,101
edits
Changes
From Fellrnr.com, Running tips
no edit summary
[http://www.polar.com/en/support/m400_release_notes http://www.polar.com/en/support/m400_release_notes]
{{DISPLAYTITLE:Polar M400 Review}}
The {{Polar M400}} is a disappointing watch, with poor GPS accuracy and no limited support for [[Cadence]]. Even at its low price point it I don't think it offers good value for money. It's quite possible that Polar will address some of these issues with firmware upgrades, but for now I'd avoid it. If you're after a midrange GPS watch, I'd suggest looking at the [[Garmin 610]]. While it's an older watch, it offers far more features than the M400. The Garmin 220 is more expensive, but offers better functionality.
[[File:Polar M400.jpg|none|thumb|200px|The {{Polar M400}}.]]
=Polar M400 Pros=
* The cable to charge and sync the M400 is a standard micro-USB that's waterproof. Most watches use a specialist cable that's expensive to replace if lost.
=Polar M400 Cons=
* Unlike the [[Polar V800]], the M400 has poor [[GPS Accuracy]]. While I rely on detailed measurements and statistical analysis to evaluate GPS accuracy, it's worth mentioning that on one 18 mile run the M400 has lost over a mile. This is the worst a level of error I've seen, even worse than the [[Garmin 620]] before Garmin fixed their problems with a Firmware upgrade. (I tested the M400 with version 1.4 of the firmware and the GPS accuracy is unchanged.)
** It looks like Polar are using a different GPS chipset in the M400. The V800 uses the SiRF chipset, where the M400 uses [http://www.u-blox.com/en u-blox].
** I have seen the Polar M400 losing satellite signal with the message "There's no GPS signal". This occurred under conditions where another device is doing fine and there are not circumstances that would cause a problem.
** The accuracy you might see with the M400 on your runs may vary from my testing. If you look at the [[Detailed Statistics for GPS Running Watches| detailed statistics]] you'll see that the M400 does quite well in straight lines. This is true of nearly all GPS watches, as running in a straight line is not difficult, and even here the M400 does worse than most devices.
* The second major problem with the M400 is the lack of Polar has added support for a [[CadenceFootpod]]with version 1. To me4 of firmware, but this is unforgivable problematic. ** The Polar Stride Sensor is fully supported by the M400, with automatic calibration and it will display stride length as well as Cadence cadence. However, the Stride Sensor is huge when compared with modern Footpods, weighing over three times as much as a critical aspect Garmin Footpod. Because of runningits size and weight, it requires lacing into the shoelaces, making it a real pain to move between shoes. I could even argue that <jfs id="B00CCASIMS" noreferb="true" n="Polar Stride Sensor"/>** Some third party Bluetooth Footpods, like the "i-gotU" will pair with the M400, but then won't display cadence and prevent the M400 from recording any distance travelled. ** The Adidas miCoach Speed Cell will work with the M400, but it's not easy. By default it will pair with the M400, but you can't set the calibration factor nor can you set the M400 to use GPS for pace/distance. You have to pair the M400 with the Polar Speed Sensor to activate the most important feature of menu items you need to configure the Adidas Footpod, which is far from ideal. However, the Adidas Footpod is then a running watchreasonable size and provides cadence (though not stride length). <jfs id="B00FEJ7FBO" noreferb="true" n="adidas miCoach Speed Cell "/>.** Even though the M400 has an internal accelerometer, this is not used to display cadence. Cadence may become supported in the future, but even then the options here are currently quite limited.
* The M400 claims to have more rapid initial satellite acquisition than earlier watches, but I have not found this to be the case.
** In my testing, I found "Time To First Fix" (TTFF) on the M400 is comparable or slightly slower than the older [[Garmin 610]]. (I tested after a 4+ hour gap since the last fix as most devices will reacquire rapidly if the gap is shorter.)
** Polar states they use [http://www.u-blox.com/en/assisted-gps.html AssistNow, a technology from u-blox] which does satellite prediction. AssistNow can use a downloaded prediction file or simply calculate the positions offline. I'm assuming With version 1.4 of the firmware, the M400 does synchronization software was updated to indicate that the offline calculationfile had been downloaded, as Polar claims acquisition "as fast as in 10 second" and validity the watch will now indicate how long the file is valid for up to 3 days. However, even with version 1.4, which matches the u-blox figures for offline modeTTFF is still slow compared with competing devices. * The M400 uses Bluetooth sensors rather than the more common Ant+, limiting the choice and quality of sensors. This is likely to change over time as more devices are produced and compatibility issues are resolved.
* The M400 will only upload the data to the Polar website. Polar has introduced to the export of TCX format data, but this export is incomplete (no laps). You can work around this by using the open source projects [https://github.com/pcolby/bipolar Bipolar] and [https://github.com/profanum429/v800_downloader M400_downloader], but this is a far cry from the open approach that Garmin has taken.
* Like the Polar V800, the M400 uses visual tricks to appear smaller than it is. The watch is curved, so the first part of the watch strap is really part of the watch body. This can cause problems for runners with smaller or larger wrists. I have to wear the V800 and M400 over a wrist sweat band as my writs are quite small. (I have no problem with watches that appear to be bigger, like the [[Garmin 310XT]].)
