Speed sensor for my MTB to go along with Garmin 520?

After a recent trip with friends in which we all compared our Strava stats, it was a bit annoying to see how different the miles logged was so different between many of us. One of the guys mentioned that adding a speed sensor to the wheel makes the Garmin more accurate. Anyone know if that’s true?
I was looking at this one https://www.amazon.com/gp/product/B00JM6DKUA/ref=ox_sc_saved_title_1?smid=A3H9V1EMGQSHX7&psc=1 but the reviews are mixed. Anyone had good luck with that one or any other sensors to help improve accuracy?


Yes, adding a speed sensor (and properly setting the wheel size to match your setup) will most likely give better distance results. There is inherent error in GPS data, and this is more apparent with the more non-linear (left/right as well as up/down) for MTB when compared to road (straighter and more subtle elevation changes).

I have good luck with the Bontrager and other sensors that still use the old wheel magnet method. They are a can be bit more reliable than the accelerometer based versions. But either one is likely to give you improved results when compared to GPS.

The speed sensor is an absolute must for mountain bike riding.

Disabling auto-pause can make a big impact as well.

I have the sensor that you linked and it makes a huge difference in accuracy for me. My Garmin simply doesn’t track GPS well enough in the woods to get an accurate mileage amount without the sensor.

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Disabling auto-pause can make a big impact as well.

That can make a big difference depending on how you ride. If I’m out riding with other people and we are making frequent stops on the trail you can end up losing quite a bit of distance for each stop/start. Takes a little bit for the GPS to decide you are moving again.

I haven’t gotten a speed sensor myself yet, but not using auto pause and stopping manually has helped… except when I forget to hit start again… :man_facepalming:

Haha yeah I gave up on trying to pause on my own. Always forget to restart at least once per ride…

Thanks for the tips gents. Going to give the Garmin I linked a try.