Issues with Garmin 500 Speed Reading

Jocry

Hi,

Just wondered if anyone has experienced the issue below with their Garmin.

I received a 500 six months ago and it has been working fine up until last week. While out cycling I have noticed that the speed is acting erratic. I can be cycling at a constant speed and when I look at the device reading it will drop down about 50% for a few seconds and will then peak back up to what I would suspect is the correct speed.

This is happening constantly and what I am also noticing is that its not calculating the correct distance for some reason. I would have thought that given the incorrect speed reading it would only calculate that the average time/speed were incorrect but not the distance as well! It's odd because it will appear to track the whole route I cycled on the map but just isn't giving the correct readings! From what I can see the GPS is not dropping.

I have reset the magnet / sensor making sure they're aligned properly and also just upgraded to the most recent software and this does not appear to be resolving the issue. Cadence / HR, etc seem to be reading correctly.

I only ride the bike in the mild weather for the most part so it hasn't been exposed to rain or harsh conditions. I don't believe the device would be corroded inside but have not attempted to open it up for fear of breaking it.

I've sent Support an email and they said someone will be back on within 3 business days but just in the meantime I'm curious if anyone here has had the same problems. I've a major cycle this weekend and would love to get it resolved by then!

Thanks.

Tenzor07

Well, all I can say is sometimes my Garmin says I am doing 0.3kph when I am not moving!

So I believe there is a small bit of lag, possibly to do with the device looking for a satellite... But i'm no scientist here!

Jocry

Yeah I know that alright but I'm talking about when I'm properly moving and since it has only begun to happen there's something out of the norm with my set up

07Lapierre

Faulty Speed sensor?. Disable the Speed Sensor and go for a few spins and see if the fault is still there. Garmin warranty is very good. If the sensor is faulty, contact them and they will send you a new one.

Jocry

Cheers 07Lapierre, have heard their warranty is pretty decent alright. Will take your advice and give that a try.

As I said I've contacted them already to hoping to hear something positive back, should have made contact with them last week!

07Lapierre

You could also try putting a new battery in the speed/cadence sensor. I know you only have it a few months old, but sometimes they've been sitting on a shelf for months before you buy it, so it could be just the battery is low. That would also give irratic readings.

Jocry

Cheers, was heading to get batteries at lunch time to test that.

wotdef

On one of my spins last week when I uploaded to strava I noticed that my max speed was 94 kmh. Hasn't happened since. Maybe there was an issue with satellites, sun flares or ufo activity on that day.

Jocry

Unfortunately not wotdef, its consistent on my last 5/6 rides

wotdef

Have you tried a reset?

Beasty

See what the new batteries do first. If that does not work switch off the sensor and stick with GPS - that's accurate enough for most people (unless you spend a lot of times in tunnels or riding through forests), and will determine whether it's an issue with the Garmin or sensor

Jocry

Not within the settings of the Garmin itself but have tried the reset of the sensor sitting on the chain stay. I would have assumed though when I installed the updated software it would have done a full reset anyway

nilhg

Something like what you describe has happened to me a few times, disabling the speed/cadence sensor on the main unit, then doing a search for it always seems to resolve the problem for a month or two.

Charlie69

Jocry wrote: »

Hi,

Just wondered if anyone has experienced the issue below with their Garmin.

I received a 500 six months ago and it has been working fine up until last week. While out cycling I have noticed that the speed is acting erratic. I can be cycling at a constant speed and when I look at the device reading it will drop down about 50% for a few seconds and will then peak back up to what I would suspect is the correct speed.

This is happening constantly and what I am also noticing is that its not calculating the correct distance for some reason. I would have thought that given the incorrect speed reading it would only calculate that the average time/speed were incorrect but not the distance as well! It's odd because it will appear to track the whole route I cycled on the map but just isn't giving the correct readings! From what I can see the GPS is not dropping.

I have reset the magnet / sensor making sure they're aligned properly and also just upgraded to the most recent software and this does not appear to be resolving the issue. Cadence / HR, etc seem to be reading correctly.

I only ride the bike in the mild weather for the most part so it hasn't been exposed to rain or harsh conditions. I don't believe the device would be corroded inside but have not attempted to open it up for fear of breaking it.

I've sent Support an email and they said someone will be back on within 3 business days but just in the meantime I'm curious if anyone here has had the same problems. I've a major cycle this weekend and would love to get it resolved by then!

Thanks.

The same thing happened to mine on a long spin,it was showing some really funny readings as I was cycling but uploaded to strava with correct readings.I turned it off for a few days and seems to be working properly since.

bren_mc

I've had this issue ever since i installed it. It would work perfectly for about 10 or 15 kms and then start displaying speeds that were slow. I assumed initially it was the sensor that wasn't positioned correctly but I found it impossible to fix because it was initially giving the correct readings. In fact I disabled the speed sensor and now just use the GPS to record speed and distance. I meant to go back and try and fix it properly but completely forgot about it til I saw this thread. I did notice that when I was using it, even though the display could be completely wrong in terms of speed and distance, the recorded data would be fine when uploaded to strava. I'll try changing the battery and see if it does the trick.

CramCycle

Its most likely the sensor, probably batteries, try a reset first though. It is either flicking to the GPS, hence the inconsistent readings. or the battery is on its last legs in the sensor.

Jocry

My issue with it is the fact that I've covered 2800km this year without any problems and then all of a sudden its beginning to give trouble. I think I'll try the batteries later and see if it works, failing that Im not sure what I'll do!

Jocry

Took the battery out of the sensor this morning for the commute in and Garmin read consistently all the way in, getting a battery this evening which should hopefully resolve the issue!

del_boy13

Had this problem and replacing the battery sorted it out.

I have another question about the temperature sensitivity on the Garmin 500 mine always seems to read about 2 degrees more than it should. Has anyone else this problem?

Jocry

del_boy13 wrote: »

I have another question about the temperature sensitivity on the Garmin 500 mine always seems to read about 2 degrees more than it should. Has anyone else this problem?

You know I've never actually tested / checked that, guess I'll be doing that on the way home so

CramCycle

It always does if you have it inside or in your pocket soon before you start recording. If this is an issue for you. I recommend leaving it outside on your bike (if safe and possible) while you are getting ready, that way it will equilibriate before you ride off hopefully. For exampl during the cold snap last year I was walking out of work at 25C, to a temp outside of 2/3C, when I got home the temp for the ride would be 8C as it would average the temp out.

talkabout

Anyone ever have a problem with device not connecting with computer. I have a Garmin 500 and it works fine but when we tried to connect a friends unit we get nothing or an error message "device not recognized". Its unlikely to be the cable or computer as obviously it reads my unit just fine and we have tried it on a second computer. The unit itself appears to be fine but he recently had to delete all his rides as the memory was full. Anyone have any suggestions??

del_boy13

CramCycle wrote: »

It always does if you have it inside or in your pocket soon before you start recording. If this is an issue for you. I recommend leaving it outside on your bike (if safe and possible) while you are getting ready, that way it will equilibriate before you ride off hopefully. For exampl during the cold snap last year I was walking out of work at 25C, to a temp outside of 2/3C, when I got home the temp for the ride would be 8C as it would average the temp out.

I tried this a couple of times left it on the bike overnight and the temperature is still an average of about 2 degrees warmer.

On the problem with the device not been read I have gotten that warning but it is always available when I look in My Computer.

JMcL

talkabout wrote: »

Anyone ever have a problem with device not connecting with computer. I have a Garmin 500 and it works fine but when we tried to connect a friends unit we get nothing or an error message "device not recognized".

Assuming you're connecting to a computer that uses the Garmin Communicator plugin, you might want to make sure you're on an up to date version of that. Maybe uninstall/reinstall it. Since yours works it might be a case that your friend's unit has more recent firmware which isn't recognised by the version of the plugin you've installed.

Worst comes to worst, you can probably mount the 500 as a USB drive and access the activities that way, but it's painful as you can only upload one file at a time to Garmin Connect

mick121

sorry to hijack your thread op but am wondering if anyone can advise me about battery care.Having reciently got a garmin 500 which i love i find myself uploading my info to strava.My queary is I only do about 40-50k spins and the battery is still 80% or so full.When i connect to the laptop via usb it starts charging the battery.I always leave the unit connected untill its 100% charged but am i damaging the battery by only giving it a top up charge and if so what can i do to prevent this.Thanks and sorry for hijacking.

Jocry

mick121 wrote: »

sorry to hijack your thread op but am wondering if anyone can advise me about battery care.Having reciently got a garmin 500 which i love i find myself uploading my info to strava.My queary is I only do about 40-50k spins and the battery is still 80% or so full.When i connect to the laptop via usb it starts charging the battery.I always leave the unit connected untill its 100% charged but am i damaging the battery by only giving it a top up charge and if so what can i do to prevent this.Thanks and sorry for hijacking.

I'm the same as yourself regarding topping up on 80% or so, and having just disconnected the sensor yesterday and having consistent readings I can only assume that while the battery in the sensor was damaged (havent tested the new battery yet), the battery in the Garmin is OK. There's not much you can do to stop the device charging when you plug it in as it automatically charges. Its a good point, I dont know if you can leave the Garmin plugged on with it automatically turning itself off but what I know with some devices (I could be wrong) that its not bad to let it completely die every so often. Could be an old wives tale but I will stand corrected if so!!!

mick121

Jocry wrote: »

I'm the same as yourself regarding topping up on 80% or so, and having just disconnected the sensor yesterday and having consistent readings I can only assume that while the battery in the sensor was damaged (havent tested the new battery yet), the battery in the Garmin is OK. There's not much you can do to stop the device charging when you plug it in as it automatically charges. Its a good point, I dont know if you can leave the Garmin plugged on with it automatically turning itself off but what I know with some devices (I could be wrong) that its not bad to let it completely die every so often. Could be an old wives tale but I will stand corrected if so!!!

Cheers Jocry my thoughts too.
Having used battery powered tools etc I was advised to drain completely when possible and do a full charge to prolong battery life.Not sure if this applies to Garmin but sounds like good practice to me.

CramCycle

Those style of batteries are better off not being let die AFAIK, once the low battery sign is on it is time to charge, there is a reason, I just don't remember what it is

mick121

CramCycle wrote: »

Those style of batteries are better off not being let die AFAIK, once the low battery sign is on it is time to charge, there is a reason, I just don't remember what it is

Sounds ok but mine only looses about 20% before it gets charged.

CramCycle

mick121 wrote: »

Sounds ok but mine only looses about 20% before it gets charged.

There should not be any noticeable issues in this scenario.

mick121

CramCycle wrote: »

There should not be any noticeable issues in this scenario.

Sound man.maybe I should cycle longer to drain the battery he he

CramCycle

mick121 wrote: »

Sound man.maybe I should cycle longer to drain the battery he he

I used mine on a short commute every day for a year with a few longer spins at the weekend, charged most days when plugged in, after a year went on a really long cycle and it lasted a few hours over its advertised duration so I can't see it being an issue.

mick121

CramCycle wrote: »

I used mine on a short commute every day for a year with a few longer spins at the weekend, charged most days when plugged in, after a year went on a really long cycle and it lasted a few hours over its advertised duration so I can't see it being an issue.

Excellent, thanks for your advice

JMcL

mick121 wrote: »

sorry to hijack your thread op but am wondering if anyone can advise me about battery care.Having reciently got a garmin 500 which i love i find myself uploading my info to strava.My queary is I only do about 40-50k spins and the battery is still 80% or so full.When i connect to the laptop via usb it starts charging the battery.I always leave the unit connected untill its 100% charged but am i damaging the battery by only giving it a top up charge and if so what can i do to prevent this.Thanks and sorry for hijacking.

Lithium Ion batteries as used in the 500 don't suffer memory effects to the same extent as older rechargeables (though it's recently been discovered that they do have actually have a memory). Best practice to maintain a long life is generally accepted to be to not let them deplete too much before charging, so keeping them topped up daily is fine.

As an example, my wife and I both have laptops which were bought at the same time and are now heading for 4 years old, the battery in hers is knackered as she tended to run it off battery a lot (it is a laptop I suppose) whereas mine would have spent more time plugged in with the result that I probably still get about 80% of the original runtime off the battery even now