So I just got a Garmin Edge 520 and will be getting at least the cadence sensor. Other than preventing data loss from gps signal loss, is there any advantage to using the speed sensor over the gps for determining speed and distance?

thanks

Tom

The speed sensor responds much more quickly to speed changes than the GPS alone.

i have both for my 520 and,can say not realy. the only situation is maybe being able to see speed on a trainer. which is only helpful to compare speeds between one work out to another or for something like swift on a normal trainer. other that cadence is realy all thats needed.

Gps sensors are notoriously erratic at short intervals. A wheel mounted sensor will be more accurate.

Which may or may not be material depending on your goals.

Also, if you use auto-pause, the wheel sensor helps prevent false pausing due to GPS position/speed noise.

Depends on your luck with firmware.

I've turned off auto-pause, as randomly riding at 15-20MPH (with fresh batteries, and in rural areas) my Edge will chirp that it is pausing for 5-10 seconds.

dang that would be annoying i havent ran into that with mine. maybe its the wheel speer sensor?

Had it happen with both a GSC10 and the magnetless accelerometer sensor and my Edge1000. Although it tends to happen less frequently if the accelerometer sensor is on the front wheel hub and not the back. In both devices in all cases, batteries were ruled out. Frame isn't abnormally large, a custom job but still within in the 56cm roadie size class.

Costing for extended periods can trigger it IME. "Extended", meaning more than 10-15 seconds. One of the perks of living on the Great Plains, there ain't much opportunity for coasting.

Thanks for the responses. I think I'll get the cadence and speed sensors, after all, it's only money, lol.

FYI, the Garmin speed sensor is not an accelerometer. It is a magnetometer which senses its own position relative the ambient magnetic field, typically the earth's magnetic field.

I can be affected by strong magnetic fields such as magnets for other sensors. Some have reported that it does not read correctly when riding over bridges built with large iron beams. Dynamo hubs can also cause interference.
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-Tim-

How about with Chris King R45 hubs on a sunny day on a rural road in the middle of nowhere? What's Garmin's excuse for that behavior? Like I said GSC10 sensor does the same thing with E1K. Are the new sensors allergic to titanium framesets?

In addition, you'll get the most reliable distance calculations using a properly calibrated speed sensor.

What do you want from me?

How about you open a ticket with Garmin support and ask them?

Plus they will continue to give speed and distance when satellite connections are poor or non-existent in certain areas or with certain weather conditions.

It really depends on your goals, but I'll go out on a limb and say no.

If your cadence is too low, you could be hurting your knees, or fatiguing yourself too early. If your power or heart data is off, you won't get the fitness benefits you expect and are working for. If your distance data is off slightly (1 to 2 %) nothing bad will happen.

Yours is defective.

I have an Edge 800 and a Fenix 3; neither of them have ever done that. The guy who sits next to me has a 920XT, it's never done that either. What you're describing is not typical at all.

You should call Garmin and get this resolved. Here, I'll google their number for you: 1 800-800-1020. They will probably ask you for an example activity, then send you a free replacement.

On a device I purchased 14 months ago? Yea right. I don't even need to waste my lifespan contacting Garmin to know I'm SOL.

Heck they wouldn't even do that with Edge705/305 units with the design flaw with the metal-fatiguing battery spring resulting in Edge Narcolepsy. Free replacement? What planet do you live on?

Some people think they are victims but they are really volunteers.

I would have either got it fixed 14 months ago, or got my money back. Unless you set an auto-pause threshold of 25 mph, the feature coming on at 20 mph is a defect.

You'll need it for some indoor trainers. I have a 510 without speed, the lag in realtime speed is never an issue for me. My wife got a new 520 bundle that included the speed sensor and she uses it with the trainer to ride Zwift - she's loving it. (for the record, I've stolen the speed and cadence sensors off her bike for some Zwift rides too).

14 months ago it was easily written off as an Edge "feature".

You do know that you're talking about Garmin....that sells devices that are broken on a software level on release and are supremely unreliable, only to sort of fix them after 1-2 years of software updates?