I have been using my new purchase at the Velodrome as the Edge 1000 is a bit big for track use and got speed readings of 23mph with GPS off, (should have been 31mph according to cadence and gear inches).

And 52mph with GPS on, which of course is far preferable, but unfortunately still inaccurate.

I have contacted Garmin who are not much use so far. They say to make sure wheel size is programmed correctly, I can’t find any such option in the manual or on the device.

Anyone else have odd readings?

Zzz

I’ll give you £50 for it 🙂

can you adjust the sample frequency?

Good question. I don’t even know what the question means, let alone the answer 🙄

I’ll have a look at the manual. How would it help BTW?

Thanks

GPS signal indoors? Then poor signal and GPS isn’t that accurate.

The gps sampling on the 25 is poor compared to the bigger ones, no idea if that effects the readings from a cadence or speed sensor. Are you using the magnet ones or the new accelerometer ones, there was a review on dcrainmaker which said the new ones had poor accuracy compared to the old magnet ones.

Speed calculated off ANT+ sensor, GPS is off.

Also, I thought (at least this used to be the case) the wheel size was calculated based on a gps reading, so you might need to ride around outside for a bit with gps on to get it calibrated?

Oops,

Sorry STATO, missed your first post, that is interesting, I am using the newer versions but would be prepared to get a set of magnetic ones as I am always swapping the sensors over between bikes.The Cadence sensor seems fine but the speed sensor is off.

and then for your second post…

Ah, wondered how they did this, thanks STATO! That totally makes sense. I wonder why the guy from Garmin never mentioned that?

Cheers,

Zzz

I know a couple of others who have had issues with the newer sensors at the velodrome (the speed plot has bigger spikes than one recorded with a magnet sensor). Reckon it might be to do with the banking and the bike leaning over impacting on the accelometer

Thanks Omar,

I was using an Edge 1000 and it seems pretty consistent using the newer sensors but I wanted something a little smaller for the track. The fact that it was overcompensating when GPS was ‘On’ lead me to turn the GPS off. Then it gave me readings of 23mph peak and 8 mph average (not possible on 42.5 degree banking). Calculating the speed from cadence and gear inches gave me an actual sprint speed of 32mph peak. Garmin are pretty useless so far.

(Having difficulty not shouting ‘Omar’s Coming’! at the top of my voice and scattering the family into hiding places.)

OK, Little update by following STATO’s thread…

From the Garmin Forum “ride for at least a mile in a straight line. This is how the Edge 25 will calibrate your wheel size for your speed sensor so that you get the correct distance, both when riding indoors and outdoors”.

There are also folk there stating that the GPS over rides the sensor when active, although it should not do this, leading to random peaks and troughs in on/off GPS conditions.

Zzz

Have not had a problem yet but I’m not riding inside.

Are you using an optional speed sensor that fits to the hub?

My old man uses the turbo trainer and the 25 combined with a speed and cadence sensors.

Outside my 25 has been spot on.

Reset?

So, for anyone interested, it seems there is a problem with the Edge 25 that Garmin are not acknowledging publicly but are working on in the background. They have known this since December 2015 and are working on a firmware fix for but have not yet achieved this. The GPS should act as a back up to a speed sensor, which is designed to take priority over sending speed readings for the device in the aid of accuracy. But it isn’t, and GPS is taking over and sending inaccurate info instead, or cutting in and out in areas of poor reception and sending peaks and troughs of readings.

That’s the rub of it anyway, for the discussion go here…

https://forums.garmin.com/showthread.php?342193-Edge-25-and-Speed-Sensor-setup-issues

I’m surprised that no one on here noticed it yet, or have they? Does anyone have an accurate on they can stand by, just interested to know whether it may be bad units or a bad design.

Cheers,

Zzz

Interesting. Can you not just turn off the GPS and manually set the wheel circumference?

Where is the speed sensor relative to the head unit? I was getting erratic reading on my 520 and new style speed sensor until I moved it from the rear hub to the front. Steady and consistent now.

Why do you want speed and cadence on a velodrome? Speed = cadence. Turn off GPS and remove the speed sensor. Multiply by a constant if you must. When I ride fixed (a lot) I only ever look at cadence.

I presume the 25 is mounted under the saddle? Is it a distance thing?