Inaccurate cycling distance for Garmin instinct 2 solar tactical

The first thing I'd do is update your firmware to the latest release (12.23).  

You are a few revisions behind:

Hi Dan, thanks for your answer.

However I cannot find the way to update my watch due to info that says no update is available.

PS My device is Asia Pacific version which is not beta joinable per information reported by Chris.

It looks like a problem with the barometric altimeter. The total elevation gain of 17km did the difference. Possibly because of some debris or moisture in the sensor port. Try cleaning it, and check some other tips for altimeter problems at Troubleshooting the Instinct Series Altimeter and Barometer | Garmin Customer Support. You can also protect the pressure sensor port with a sweatband, or even with a piece of tape. Also move the watch on the wrist further upper from the wrist bone. When it is too close to the hand, when bending the wrist, you can push against the port opening, and create additional pressure resulting in the wrong reading.

You can also enable the Elevation Corrections in Garmin Connect Web at this specific activity. (What Is the Elevation Corrections Feature in Garmin Connect? | Garmin Customer Support)

Thank you for your answer trux. That's a very reasonable explanation to the cause of inaccuracy. I'll try wearing the watch above my wrist bone a bit and see if the results changes. 

Hi Mi2ac1e
I have a similar problem with my Instinct 2 Solar and was wondering if you could tell me what (if anything) fixed it for you?
The distances registered for cycling activities by my watch are way off. A 115km ride is registered as 38km, even though the gps readings (the map) are otherwise correct.

4510646 said:

A 115km ride is registered as 38km

It does not seem to be the same case as the OP, where the distance was increased due to high elevation gain. Shorter than the real distance cannot be caused by elevation gain.

A possible reason could be that you have a speed sensor on the bike that was not calibrated and was connected to the watch. We could perhaps find the clue if you share the link to the concerned activity.

Hi trux,

Thank you for your reply. Indeed, the issue could (seems to) be very different.

I have changed the distance of the activity discussed in my previous post, but another activity has the same issue, and I have not changed any of the data for that one. It says that the total distance is 9.95km while actually it is closer to 40km. The map is correct. https://connect.garmin.com/modern/activity/14173019872

Several of the solutions mentioned in this thread could be relevant for my issue as well. I have a custom wrist strap due to which the watch is quite loose and may be resulting in the kind of pressure on the reader that you mentioned previously. I have put on the standard strap and will check what that does when I go out cycling again later this week. I will keep you updated.

Thanks again for your input.

4510646 said:

It says that the total distance is 9.95km while actually it is closer to 40km. The map is correct. https://connect.garmin.com/modern/activity/14173019872

The strap plays no role in the distance estimation at bike rides. The reason is exactly what I suspected - you have a speed sensor on the bike, that is not correctly calibrated:

You either have to calibrate it, or disconnect it, if you do not want to use it.

BTW, if you are sure you have no speed sensor on your bike, then it had to be a sensor of someone else riding near you. Remove it from your watch and disable the auto-connection in the menu Sensors & Accessories

Thank you so much. I have a new cadence sensor that is not syncing properly. Indeed the issue started after I paired that one. I am removing it from my watch and will let you know how it goes later this week.