Any major issues with Garmin's new magnet less speed/cadence sensors?

It sounds like you might get more support by posting on the Bryton forum. The Garmin sensor is just sending a count of wheel clicks (revolutions). The issue is more likely at the head unit end it terms of how it is processing and storing this data.

I'm not sure it might be a problem with the head unit since it has been working fine with a couple of other ANT+ sensors (HRM, cadence and speed from BT'Win and even with the cadence magnet-less sensor from Garmin). Is there any test procedure I may follow so I can be sure if the problem is with the speed sensor ?

There are tests you can perform on an Edge to capture the ANT+ traffic and see what it is sending. I don't know if the Bryton has such tools.

If you have an ANT+ USB stick you can download the ANTSimulant and capture the ANT+ traffic from the BSS (Bike Speed Sensor).

It could be that they (Bryton) are not handling the stand alone speed sensor ANT+ traffic correctly. Each sensor type has it's own set of messages so it is quite possible for a unit to handle some sensors correctly and others not.

Do you know what format the Bryton stores the activity files on the unit in?

About the only thing you could do is to get somebody with an Edge to test the sensor. But I think it must be some kind of protocol issue that the Bryton has with that sensor. As Alan said the sensor just transmits triggers per time period. If the sensor transmitted bad data or even dropped out from time to time, the Bryton should still have a speed value. Maybe it would be a bad speed value but there should be one. Is the distance about right? I think the head units actually compute distance first from the sensor data and then compute speed based on distance over time.

There are tests you can perform on an Edge to capture the ANT+ traffic and see what it is sending. I don't know if the Bryton has such tools.

If you have an ANT+ USB stick you can download the ANTSimulant and capture the ANT+ traffic from the BSS (Bike Speed Sensor).

It could be that they (Bryton) are not handling the stand alone speed sensor ANT+ traffic correctly. Each sensor type has it's own set of messages so it is quite possible for a unit to handle some sensors correctly and others not.

Do you know what format the Bryton stores the activity files on the unit in?

I will test the sensors with an Edge unit.

Once recorded, the only way you may download track log from the unit is by means of a PC software which may export to BDX (proprietary), GPX, and TCX.

About the only thing you could do is to get somebody with an Edge to test the sensor. But I think it must be some kind of protocol issue that the Bryton has with that sensor. As Alan said the sensor just transmits triggers per time period. If the sensor transmitted bad data or even dropped out from time to time, the Bryton should still have a speed value. Maybe it would be a bad speed value but there should be one. Is the distance about right? I think the head units actually compute distance first from the sensor data and then compute speed based on distance over time.

I will.
You might be true. It seems to be a protocol handling issue.
Regarding the distance values, I'm not sure they are true. Being honest, I haven't checked them.

How have you configured the Bryton? Having a quick look through the user manual GPS takes priority unless you configure it otherwise.

Sensor priority issue: By default, your speed source would always come from priority 1 (GPS). It would only switch to priority 2 (Speed Sensor) if GPS signal is lost. Similarity, it would switch to the next priority if the previous one is not available. If you would like to do indoor training, please set speed source from Speed Sensor or Dual Sensor based on the one you would like to record your speed

I'm not sure my Briton unit (rider 20, entry level) has this kind of configuration. I'm going to look for it but the problem might really be a protocol handling issue.

I thank you two for all the support given.
Once I have a solution, I will register it here so it may be a direction for others that may face a similar problem.


P.S.: As I stated, my Bryton unit does not allow to configure the priority for speed measurement. However, I turned off the GPS receiver and tested the speed sensor so the only speed source was the sensor, but the problem is still the same. :(

I was looking at the manual for the 60 as I did not know what model you had.

It is an interesting default. It is the opposite approach to that which Garmin has taken.

On an Edge the speed sensor takes priority over the GPS.
On the Bryton the GPS takes priority over the sensor, which makes me think that unless you are spending time on a trainer and switch the GPS off there may not be much value in having the speed sensor unless you can flip the priority.

I was looking at the manual for the 60 as I did not know what model you had.

It is an interesting default. It is the opposite approach to that which Garmin has taken.

On an Edge the speed sensor takes priority over the GPS.
On the Bryton the GPS takes priority over the sensor, which makes me think that unless you are spending time on a trainer and switch the GPS off there may not be much value in having the speed sensor unless you can flip the priority.

Bryton approach is at least strange. It doesn't seem to be a rational approach. :D

FWIW. Garmin originally gave priority to GPS. The 305 remained that way. The change was made after the 705 had been released with a firmware update.

FWIW. Garmin originally gave priority to GPS. The 305 remained that way. The change was made after the 705 had been released with a firmware update.

The problem was with my Rider 20 head unit. I'he been using the speed sensor with Edge 500 with no problem. BTW, how can I configure my Edge 500 so it use the speed reads from sensor over the speed reads from GPS?

The Edge 500 gives priority to the speed data from an external speed sensor over the speed data computed using the GPS data. You do not have control over this ordering, but it is the order you wanted.