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

On the 500 I think it is an attribute of the bike profile

Bike profile -> Bike details -> more

Not reading high cadence

Hi All,

I seem to have on issue with my new ANT+ magnetless cadence sensor and wondered if anyone else has seen anything similar.

I use my track bike on rollers for indoor training and like to do intervals of high cadence. My old sensor fitted to my road bike can happily read up to 180+rpm without any issues but when I took my new track bike and new cadence sensor for a spin it kept cutting out if I went over 170rpm.

Obviously I need to do some more experiments swapping the sensors between bikes and so forth but just wondered if anyone else had seen anything similar? Is there a maximum cadence these sensors can detect?

Both sensors paired to same edge1000 - but not both active at the same time.

There is a maximum cadence value, but the max value is not a single value, but rather it is related to the length of the crank. Or more precisely to the distance (radius) of the sensor from the bottom bracket. The sensor is using accelerometers, I'm guessing you are hitting the limit on what G-Force the sensors can report. This is a function of the rpm and radius. I'm don't know how long the cranks are that you are using or where the sensor is positioned along the crank, but you could try moving the sensor a bit towards the bottom bracket and see if that allows you to register a higher reading.

Thanks for the reply, something for me to look into. I did try with the sensor right next to the BB and once half way up the 165mm crank. If anything it was slightly better with the sensor further out i.e. bigger radius but testing was limited.

Worse case scenario would be I just swap sensors between bikes as I doubt I would be doing 170rpm on the road!

Also, I've just had a thought and realized that I had my baby monitor right next to me when I was on my rollers last night and I know that it brings my 2.4ghz wifi signal to its knees. The ANT sensors also use that frequency I'm sure that would not have helped matters.

Interference can be a problem but I don't think it would show up as an incorrect reading but just as drops in the data. I believe the sensor has a timer clock and sends triggers per time period. That way the head unit can miss some transmissions and still get the correct number of triggers.

Magnet-less speed sensor off-road FAIL

I just ordered a set of magnet less speed/cadence sensors to mount on my bike and use with my Garmin 800.

Have any of you experienced any major issues (or any issues) with the new sensors?

Let me know what your experiences have been.

Thank you.

Speed sensor does NOT record accurate distance if used off road on rough terrain (ie MTB). :(:mad: The accelerations of the wheel up and down caused by bumps in the trail are interpreted as additional wheel revolutions. A 23.5 mile ride last week was recorded as 27.1 miles. Real mileage verified 3 different ways.

Other user reports same here: https://m.reddit.com/r/MTB/comments/2mcv8w/any_one_use_garmins_magnetless_sensor_on_their_mtb/cm7pwgn

Garmin, can you release a magnet based speed only sensor? The current offering is no good in the woods and not needed on the road (I guess there would be value if you wanted to use a trainer...).

The current magnet less speed sensor does not use acceleration to determine wheel movement, but rather the rotation of the sensor through the earths magnet field. Check the sensor setting on the Edge. For use on a MTB I would recommend manually setting the wheel size rather than using the automatic option. That why the value will not change.

Rotation through earth's magnetic field

The current magnet less speed sensor does not use acceleration to determine wheel movement, but rather the rotation of the sensor through the earths magnet field. Check the sensor setting on the Edge. For use on a MTB I would recommend manually setting the wheel size rather than using the automatic option. That why the value will not change.

Wheel size set manually and correct. If it is a magnetic field based reading, then perhaps another poster was closer to the issue: semi metallic disc brakes creating a magnetic field?

Magnetized items on the bike could cause an issue. I have seen problems with bikes when parts of the drive chain has gotten magnetized.

Wheel size set manually and correct. If it is a magnetic field based reading, then perhaps another poster was closer to the issue: semi metallic disc brakes creating a magnetic field?

If the sensor is on the back wheel it may be the chain. Try the front.