530 wont display speed from speed sensor, will only display GPS speed

I had tried that but it made no difference

What happens if you pick up the bike and just spin the wheel mid ride, does it still register like it did indoors?

FWIW, I’m also using the GSC10 on my good bike. Haven’t ridden the other bike with Hub sensor yet since getting the 530 but that sensor is a few years old, it’s not one of the latest ones.

I think I'm seeing a similar issue. I noticed the other day when riding down a fast, tree-covered descent. I would estimate I was doing 60kph, but the Garmin was only reporting 30kph. When I emerged from the tree cover, the speed went up to a more realistic value. 

My 530 recognises the speed sensor but when I go into the sensor details the screen cycles between these every few seconds:

If I manage to select the About, it then cycles between these:

The sensor is mounted on the rear hub and if I spin it whilst the bike is stationary, no speed is reported. I tried putting it into indoor mode too to disable GPS. Same issue - no speed reported from sensor. Even though battery was reported as OK, I replaced it. Made no difference.

I did a check on my wife's bike with a separate 530 and speed sensor. No issues there. I then paired my speed sensor to her head unit and I saw the initial problem again. One thing I noticed was that my wife's speed sensor was a newer firmware version, 2.5.

Based on this, either my speed sensor is failing or there is a compatibility issue with the 2.3 firmware and Edge 530. Anyone know how to update the firmware on the speed sensor? I tried searching for it in Garmin Express with an ANT+ dongle, but it doesn't find it. Do I need to use the RemoteSW option on my 530?

Try putting the sensor on the front hub (which is a problem if you use an indoor, wheel on Trainer). Sometimes the drive train can become magnetised and interfere with the sensor, sometimes I think the sensor is just a bit too far away from the Head Unit and blocked by your body.

I had a similar issue with my Edge 25 when it was new!  It took months to resolve but a firmware update finally fixed it!

https://forums.garmin.com/sports-fitness/cycling/f/edge-20-25/106806/edge-25-and-speed-sensor-setup-issues

aweatherall - what tool did you use to view FIT file details?

aweatherall said:

As a test try putting the new speed sensor on the front wheel instead of the rear wheel.

I also have problem with the way how 530 displays speed. I dont know whether it picks up gps speed or not, but all my three bikes have speed sensors mounted on the front forks, and have magnets on the front wheels.

My speed fluctuates two much on 530 vs my other two non-Garmin cycling computers.

I checked multiple times whether my speed sensors are really connected. Also checked whether speed is calculated rolling the first wheel with my hand, while not moving with/riding on the bicycle, of course. :-) All my tests showed that both speed sensors are ok, and my magnets are properly positioned.

As an important piece of info, some of my bicycles have multiple magnets on the front wheel, certainly the wheel circumference is decreased proportionally.

One bicycle had had only one magnet, and I made an experiment gradually increasing the number of magnets while decreasing the circumference. The level of fluctuation is increased so while I was simply cruising at 15-17 km/h, originally it fluctuated by 0.5-0.7 km/h, with 4 magnets it went up to 1.5-2.0 km/h. Second by second.

So maybe the whole problem comes from data processing, the CPU of 530 is not fast enough. Maybe.

Anyway I have enough bicycles, and enough cycling computers to state something smells as regards speed coming from speed sensors.

Any idea how to improve the situation or how to report it to Garmin as some unquestionable problem?

- said:

I also have problem with the way how 530 displays speed. I dont know whether it picks up gps speed or not, but all my three bikes have speed sensors mounted on the front forks, and have magnets on the front wheels.

My speed fluctuates two much on 530 vs my other two non-Garmin cycling computers.

I checked multiple times whether my speed sensors are really connected. Also checked whether speed is calculated rolling the first wheel with my hand, while not moving with/riding on the bicycle, of course. :-) All my tests showed that both speed sensors are ok, and my magnets are properly positioned.

So 3-4 years ago I would have been not alone with my problem / observation, but in 2022 and 2023 am I the only person who has been experiencing that mounting classical ANT+ speed sensors to our bicycles does not exclude a heavily fluctuating instantaneous speed displayed on 530???

Sidenote: I observed a small improvement, though.  In the meantimeI sold one of my bicycles, a beautiful high-racer recumbent, so now I have this unstable speed problem only with two. (saying with silent, sarcastic and ironic laugh)