Sensors

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basilio
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Sensors

Post by basilio »

Hi John.

I would like to know if PP is compatible with the GEMINI 200 sensors.

Thanks.

Tb
Velocomp
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Re: Sensors

Post by Velocomp »

We have not tested these but their technical information says that they are ANT+. If so, they should work.
John Hamann
basilio
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Re: Sensors

Post by basilio »

OK. Thanks.
discipulus
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Re: Sensors

Post by discipulus »

basilio can you let me know how the GEMINI 200 sensor works for you in terms of reliability and good data? I might have to try a different speed sensor because my Garmin magnetless speed sensor is dropping speed too often (it has a brand new battery). So, I may consider getting it too if you're having good luck with it. Thank you.
Velocomp
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Re: Sensors

Post by Velocomp »

discipulus wrote:basilio can you let me know how the GEMINI 200 sensor works for you in terms of reliability and good data? I might have to try a different speed sensor because my Garmin magnetless speed sensor is dropping speed too often (it has a brand new battery). So, I may consider getting it too if you're having good luck with it. Thank you.
Put your Garmin sensor on your front wheel hub; that should fix the problem.
John Hamann
discipulus
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Re: Sensors

Post by discipulus »

Velocomp wrote:Put your Garmin sensor on your front wheel hub; that should fix the problem.
You made an assumption. It is on the front wheel hub; problem exists.
Velocomp
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Re: Sensors

Post by Velocomp »

discipulus wrote:
Velocomp wrote:Put your Garmin sensor on your front wheel hub; that should fix the problem.
You made an assumption. It is on the front wheel hub; problem exists.
Yes, I did draw that conclusion; sorry that my instinct was wrong.

Please post a ride file showing this problem and I will take a look.
John Hamann
discipulus
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Re: Sensors

Post by discipulus »

Velocomp wrote:
discipulus wrote:
Velocomp wrote:Put your Garmin sensor on your front wheel hub; that should fix the problem.
You made an assumption. It is on the front wheel hub; problem exists.
Yes, I did draw that conclusion; sorry that my instinct was wrong.

Please post a ride file showing this problem and I will take a look.
Tom pointed out the speed sensor problem a few days ago when I needed help with a ride I did to determine my FTP. It turned out the ride data couldn't be used. So now, I'm using what I think is my FTP based on an old test that I did on another bike. I'm pretty sure the original battery was still good, but I replaced it with a new one anyways as Tom suggested; unfortunately, the problem still persists.

Anyways, I'm in contact with Garmin product support via email about the issue, and I'm waiting for their response.

I've attached an O&B cal ride and a ride file for a 3x(5 minute Z3 + 3 minute recover) interval workout that I did yesterday. Intervals start at around 26.5 minutes.

The following image represents what I saw during my ride. During my intervals, I saw (on my watch) zero power for about a minute in each 5 minute interval. I never stopped during these intervals, and I did my best to put out power on the declines.
Three intervals representation
Three intervals representation
three_intervals.png (177.35 KiB) Viewed 9664 times
It's been frustrating because I've been experiencing these problems for approximately the last eight rides. Going forward, I'll be doing more zone training, and I need reliable data so that I can stay focused on my training instead of the sensor issues.

Sorry, I didn't mean to hijack basilio's thread.
Attachments
iBike_02_15_2018_1025_18_Miles_HiDef.ibr
Three intervals between 26 and 50 minutes
(611.63 KiB) Downloaded 264 times
iBike_02_14_2018_0611_3_Miles_CalRide.ibr
O&B cal ride
(108.14 KiB) Downloaded 268 times
Velocomp
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Re: Sensors

Post by Velocomp »

Yes, I do see dropouts in your speed data. These dropouts will also cause screwy problems with power and slope.

Presumably, Tom has asked you to "hard reset" your speed sensor and to install a new battery. Have you done both of these things?

If you've done both these things and there still is a problem, then it would appear your speed sensor is defective.
John Hamann
discipulus
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Re: Sensors

Post by discipulus »

Velocomp wrote:Yes, I do see dropouts in your speed data. These dropouts will also cause screwy problems with power and slope.

Presumably, Tom has asked you to "hard reset" your speed sensor and to install a new battery. Have you done both of these things?

If you've done both these things and there still is a problem, then it would appear your speed sensor is defective.
Thanks for taking a look. Yes, I did as Tom asked. I hope I did the "hard reset" correctly: inserted a new battery in a reversed direction/polarity into the speed sensor for 10 seconds then installed the new battery into the speed sensor in the correct polarity position. Hopefully Garmin will send me a new working sensor.

Regards,
Paul
Velocomp
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Re: Sensors

Post by Velocomp »

Paul, once you get your new sensor operating please post a ride file.
John Hamann
discipulus
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Re: Sensors

Post by discipulus »

Velocomp wrote:Paul, once you get your new sensor operating please post a ride file.
Ok, will do. But first, how do I change the sensor for the profile loaded into the PP?
Velocomp
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Re: Sensors

Post by Velocomp »

Wake up the sensors on your bike, then press-hold the PP button for about 4 seconds, until it starts to flash. Release the button.

PP will pair to your new sensors. The rest of your profile information will remain unchanged.
John Hamann
discipulus
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Re: Sensors

Post by discipulus »

I'm still working with Garmin to get me a replacement speed sensor. But, I wanted to share something interesting that I've noticed.

First, I've experienced the magnetless bike speed sensor data drops pretty much every route that I've ridden where I'm currently located (Phuket).

Second, the interesting part, I have rode, more or less, the same route the last three rides, and I can now predict exactly where the data drops are going to happen; it's consistent. It's not the timing, as in how long I've been riding, but the locations. I know this because I've rode variations of the basically same route.

Reading "Understanding how the Garmin Bike Speed Sensor (BSS) measures speed", it says the sensor is using a magnetometer to "measure its own rotation within the surrounding earth's magnetic field". So, I think there are many locations here that are strongly magnetized causing the sensor to experience magnetic noise.

If that's the actual problem, the GEMINI 200 might also experience these problems for me here, too, since it also uses a magnetometer. Further, I'm afraid, I won't be able to use the PP for my training unless I can find a speed sensor that will work. However, my findings aren't conclusive yet. I'm hoping that I just happen to have a faulty sensor/overly sensitive sensor.
Velocomp
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Re: Sensors

Post by Velocomp »

Hmm..by any chance are you going by radio antennas? These can emit electromagnetic radiation at the same frequencies as your speed sensor.
John Hamann
discipulus
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Re: Sensors

Post by discipulus »

Velocomp wrote:Hmm..by any chance are you going by radio antennas? These can emit electromagnetic radiation at the same frequencies as your speed sensor.
Possibly, city/island wide WiFi is prominent and offered by various organizations. Also power/data lines look very crowded along the roads. Is it only the speed sensor broadcasting on the same frequencies, not the cadence sensor, heart rate monitor, or PP?

Garmin APAC division is preventing me from receiving a replacement sensor. They want me to take my issue to the local distributor. However, the local distributor can't do very much for me other than a.) change the battery or b) make me wait 2 months. Therefore, I am considering to buy a Wahoo speed sensor since it uses an accelerometer. I'm a little worried though because I saw posts here saying the Wahoo isn't very reliable either.
Velocomp
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Re: Sensors

Post by Velocomp »

I recommend you try another Garmin sensor. If it doesn't work then you can return it to the store for a refund, then get the Wahoo.
John Hamann
discipulus
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Re: Sensors

Post by discipulus »

Velocomp wrote:I recommend you try another Garmin sensor. If it doesn't work then you can return it to the store for a refund, then get the Wahoo.
I've decided to stop pursuing this; I don't think a replacement sensor will be any different. So, I've decided to do the majority of my training indoors from now on. For outdoor training, I'll have to get a different power meter.
Velocomp
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Re: Sensors

Post by Velocomp »

discipulus wrote:
Velocomp wrote:I recommend you try another Garmin sensor. If it doesn't work then you can return it to the store for a refund, then get the Wahoo.
I've decided to stop pursuing this; I don't think a replacement sensor will be any different. So, I've decided to do the majority of my training indoors from now on. For outdoor training, I'll have to get a different power meter.
If radio interference is the problem then I don't think another PM will solve your problem; they are ANT+ too, and their sensors are located farther away from your bike computer receiver.

Let us know how things work out.
John Hamann
discipulus
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Re: Sensors

Post by discipulus »

Velocomp wrote:
discipulus wrote:
Velocomp wrote:I recommend you try another Garmin sensor. If it doesn't work then you can return it to the store for a refund, then get the Wahoo.
I've decided to stop pursuing this; I don't think a replacement sensor will be any different. So, I've decided to do the majority of my training indoors from now on. For outdoor training, I'll have to get a different power meter.
If radio interference is the problem then I don't think another PM will solve your problem; they are ANT+ too, and their sensors are located farther away from your bike computer receiver.

Let us know how things work out.
That makes sense. However, my garmin cadence sensor, also an ANT+, is located where the other power meter, if I get one, would be located. That is, it's located near the crank/pedal. My cadence sensor isn't having the same problem (heart rate monitor also not experiencing issues). That's what made me initially think it was a problem riding through strong magnetic fields. But, I really don't know. Thank you.
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