Strange cadence readings on bike rides

While riding, I’m experiencing strange readings from my cadence sensor on my Fenix 5 plus. (NB. I changed the battery in the sensor a few weeks back and the behavior described below I did not have with a 5x using the same sensors.)

On the watch while riding, the cadence sensor seems very unresponsive. I can for example stop pedaling and the cadence does not drop to zero. It may also take longer than what I’m used to for it to respond to a change in pedaling speed. I’m not sure if it is caused by a drop out, since I did not get an alert of the sensor disconnecting or connecting.
Another strange behavior is that when I stop the activity and resume later and press start, the cadence before I start pedaling shows crazy figures. Like 23000 rpm. But it goes down to normal level when I pedal again.
On the ride data graphics in Garmin Connect post ride,
- these stops (#2) show zero speed (in ”over time”-view), but keep the cadence at the level when I pressed stop, then draw a straight line up to new level when I press start and pedal again. If it is supposed to do that, why does not speed follow the same behavior?
- Max cadence show a very high value, and I see several spikes throughout the ride.

I will take another ride this weekend without using “stop and resume later” and try the same conditions but disconnecting the smartphone. (ref connection issues discussed in other threads).

@Garmin: If the behavior detailed here is part of a known connectivity issue that will soon be fixed, please let me know so I don’t waste my time beta testing. ;)

0 Garmin-Heath over 6 years ago

jimoestman Feel free to message me privately with your email and/or contact your local Garmin Support team so we can work with you get this reported.

0 jimoestman over 6 years ago

Good day Heath,

I tried to send this message to you, but got an error message that you have chosen not to receive private messages or...

I did a little more testing today and found the communication between the cadence sensor and Fenix 5 plus was not working properly. Since I got the Fenix 5 plus, I had primarily done trail/enduro type of riding where cadence was not of interest, therefore late notice.

Today I tried with
a) phone connected and disconnected
b) smart and 1 sec recording

and the behaviour was the same.

If I stopped peddling, the watch still showed cadence (rpm)
When I stopped the activity and resumed later... the watch would show 24000 something rpm.
If I pedal and changed RPM around 80-90 rpm, the watch seemed to follow but took several seconds to respond.

I have made a GoPro recording of the watch, and recorded an activity of the test ride.
I'm happy to help out, but I don't have another device to test the cadence sensor. I recently changed battery on the sensor so I would not conclude that this behaviour is due to poor battery.

Thank you for your assistance.

Best regards,
Jim

0 jimoestman over 6 years ago

Just tried another cadence sensor without any improvement.

0 Garmin-Heath over 6 years ago

jimoestman Sorry about the private message business, IT has looked at it and has claimed the issue has been fixed. Feel free to message me with your preferred email address and I will be happy to email you back.

0 Baz 8755 over 6 years ago

I have 3 bikes and until today only only 2 of them had GSC-10 which although paired with my F5+ I have never really tried as I use my trusty Edge 810 on these bikes. However today I fitted another GSC-10 to my third bike and paired it with F5+, being my 'Pub' bike it will never be used with Edge so I went for a quick ride using F5+. Sure enough I was seeing that speed pickup works fine (proved by spinning wheel so that I was sure it was from wheel and not GPS), but cadence is doing exactly the same as you describe.

I can pedal and it will pick up the cadence but as soon as I stop the value does not return to zero whereas my Edge 810 does return to zero, I thought this was rather odd and now this evening I have just seen this thread.

0 Tommylee84 over 6 years ago

Yep same thing with me, using the 5+ but with the Bontrager DuoTrap S (ant+), So this is a neat bug! ciq.forums.garmin.com/.../1379137.png