Garmin question

[The Central Scrutinizer]

I have the Garmin Edge 130 and i notice when you are riding along a tree shaded lane or road it doesn't give the correct mph due to the satellite signal ie:it might say 9mph when you are in fact doing 15mph.Does the Garmin re-calculate this at the end of the ride to give a true average mph?

 

[cougie uk]

That's interesting. I've never seen my Garmin slow down unless I've slowed down even under trees.

 

[T4tomo]

I have the Garmin Edge 130 and i notice when you are riding along a tree shaded lane or road it doesn't give the correct mph due to the satellite signal ie:it might say 9mph when you are in fact doing 15mph.Does the Garmin re-calculate this at the end of the ride to give a true average mph?

Do you just have a head unit or does it have a speed sensor too? I've noticed this is when I've switched bikes and just using the head unit alone as I don't bother moving any sensors over.

but yes it will recalc it based on overall moving time and distance.

 

[Deleted member 26715]

What does it look like when you view it in Garmin Connect, Strava, RidewithGPS is it a flat line or very jaggy?

 

[Dogtrousers]

While riding you get an current speed. This will be something like distance from last fix/time from last fix. This is what you are seeing as wrong when under cover. At the end of the ride you will get an average speed on the device display This will be something like total distance/total time (or total moving time if you have auto pause on).

I don't know anything about the inner workings of the Garmin, but I'm going to hazard a guess that once it gets a good fix again the inaccurate dithers in the track that it had while under tree cover won't have any significant effect on the total track length, and hence on the average speed.

And of course, once uploaded you're likely to get yet another different figure for your average speed, depending on which site you use.

 

[si_c]

The current speed is as noted above based on the fixes it gets from the satellite, if they are wrong then the overall track for the ride will be wrong and you'll get an imprecise speed. The only exception to this is if you are under tree cover when riding in an absolutely straight line when the GPS fix is poor, it'll more accurately track your speed for the ride.

Garmin won't clamp the ride to the road and recalculate the distance over the entire ride as that would be worse than leaving the inaccurate fix in; that being said the discrepancy between what you rode and the ride average will be very small in most cases.

 

[Sterlo]

I've got a 130 and noticed the same thing. We have a lot of tree cover around us and as soon as you come out from under cover, the speed goes up to what it should. I know it works an a time and distance average for the total speed so annoying but doesn't bother me anymore.

 

[Spiderweb]

I’ve noticed the same happens with my Garmin Edge 1000.

 

[Dogtrousers]

If it's really annoying you then the remedy is to add a speed sensor on the wheel. But I don't know if the Edge 130 is compatible.

Speed Sensor 2 Compatible Devices: https://www.garmin.com/en-GB/p/641230/pn/010-12843-00#devices

 

[si_c]

If it's really annoying you then the remedy is to add a speed sensor on the wheel. But I don't know if the Edge 130 is compatible.

I think the Garmin Edge 130 is compatible with a whole host of sensors, including Power, so a speed sensor should work.

FWIW, I use a speed sensor on one bike and not on the other, I don't particularly notice not having it on, even under tree cover. The speed it shows is the speed it shows, I don't worry too much. This is with an 820/1030+.

 

[Dogtrousers]

I think the Garmin Edge 130 is compatible with a whole host of sensors, including Power, so a speed sensor should work.

FWIW, I use a speed sensor on one bike and not on the other, I don't particularly notice not having it on, even under tree cover. The speed it shows is the speed it shows, I don't worry too much. This is with an 820/1030+.

I bought a speed sensor, because I like to have all the gadgets.
When the battery ran out. I never noticed

 

[si_c]

I bought a speed sensor, because I like to have all the gadgets.
When the battery ran out. I never noticed

I'm the same, it can be expensive unfortunately, I've got more gadgets arriving today, not bike related though. One advantage of working from home is that Mrs C is never around when the packages arrive so consequently doesn't know about them.

 

[Sterlo]

The 130 does pick up sensors (drops 'em as well), I've got one but I've got it set to cadence.

 

[The Central Scrutinizer]

thanks for your comments
I actually just got in touch with Garmin and they said no the unit wouldn't recalculate but if you were under trees for a limited time the average speed loss would be minimal.

 

[T4tomo]

I actually just got in touch with Garmin and they said no the unit wouldn't recalculate but if you were under trees for a limited time the average speed loss would be minimal.

If you upload your rides anywhere, i.e strava, then the summary stats for that ride will probably recalc. it. as stated the difference isnt a whole heap of beans and given the relative inaccuracies of most "speedos" not worth worrying about. What is does do is be consistent with itself so comparing difference efforts at different times is still valid.