View Full Version : Distance Errors between devices

05-23-2010, 10:19 PM
Just wondering if there can be some reason for the following:

On the weekend a fun run was held and there is a large discrepancy between distances recorded on different Garmin devices. The run was promoted as 14 km long, Forerunner 405 and 405cx devices came up with around about 14.5km (depending on which side of the road you ran on), however Forerunner 310xt devices all came up close to 16km.
Using data in Garmin connect (search for HBF in Perth, Western Australia) all maps look pretty much the same and yet there is a large difference in distances from the two units.

The race did run through a tunnel, could this be the reason and if so why does it not affect all units equally?

Thanks anyone for your guidance here