Charge 4 sents wrong data to Strava

[Northfizz]

Hi,

I've decided to create a new topic due to the lack of reply of the fitbit support.

So here we go again, please look for other people complains under the topic "Charge 4 GPS data is incorrect when sent to Strava"

Here are my first 3 runs that contain different data over the two applications.

Running recorded with the fitbit charge 4, then automatically synced over to strave with heart rate access enabled:

Run 1:

Fitbit tells me - 6,01 km, 30:13 minutes, 5,01" pace / Strava tells me - 5,73km, 30:13 minutes, 5,06" pace

Run 2:

Fitbit tells me - 4,58km, 21:39 minutes, 4,43" pace / Strava tells me - 4,16km, 21:39 minutes, 5,08" pace

Run 3:

Fitbit tells me - 5,11km, 22:54 minutes, 4,28" pace / Strava tells me - 4,73km, 22:54 minutes, 4,46" pace

I find it amazing how much these runs are off, I've used runnner maps to calculate my ACTUAL distance, the truth is somewhere in between - but Strava is always closer to the actual distance. 

One of the community members (because fitbit doesn't reply) advised me to change my stride length to see better results.

Beside the fact that this is a laughable workaround - it doesn't work fully, but comes more close. Meaning it's very obvious now that the entire problem is on the side of fitbit.

Here is my test run with an adjusted stride length:

Run 4:

Fitbit tells me - 7,2km, 34:57 minutes, 4,51" pace / Strava tells me - 7,27km, 34:57 minutes, 4,48" pace

Actual length calculated through runnermaps = 7,68km 

I bought a fitbit to track my running, but I end up doing troubleshooting. This issue needs to get fixed.

[Rich_Laue]

Are you recording your runs through fitbit, send the data to Strava? 

You are not recording runs with the Strava App? 

Have you checked your Stride settings? Fitbit uses both the Stride and GPS. Strava only receives the GPS data. 

I've moved the thread out of hardware support and into the Third Party sync support. 

[Northfizz]

Hi Rich,

I don't want to be rude, but I wonder if u even read my post?

"Running recorded with the fitbit charge 4, then automatically synced over to strave with heart rate access enabled:"

"One of the community members (because fitbit doesn't reply) advised me to change my stride length to see better results." + "Here is my test run with an adjusted stride length:"

So yes, I record through fitbit and then sync it over to strava. 

I lowered my stride length to 97 cm, because I run on vibram (barefeet style).

The stride length option is a joke on it's own, because it will vary based upon how fast I run - so why would you even use this as a measure.....

[Giampi71]

@Northfizz I made many tests since the release of Ionic and concluded that the distance algorithm used by Fitbit is practically based only on steps multiplied by stride calculation. Stride is somehow/sometimes/some.... evaluated by GPS but at the core the distance is just based on steps. 

As you say the stride strongly depends on the pace (and curves, and type of terrain, and many other factors) so it is unclear why Fitbit decided to use such absurd and overcomplicated algorithm. I tried several times to push Fitbit to provide a reply but the different moderators always use the same scripted answer without any further explanation so I gave up and moved to a more dedicated watch.

I agree although with @Rich_Laue that Strave receives only the GPS data from Fitbit and then apply further correction. Since anyway the GPS sensor used is very inaccurate and way too much smoothed Strava can not make miracles (although my personal opinion is that Strava algorithm is everything but good) hence the final result.

Sorry but if you're serious about running move to a Suunto/Garmin/Polar (I personally chose Polar) you won't regret it, Fitbit simply doesn't care.