GSC 10 issues
steve_kay
Posts: 197
I was about to set off for a ride today and noticed that even when the wheel was rotating, the speed would never go higher than 5 or 6 mph. I rode 50 miles and this was consistent throughout. Also, the distance measured for the 50 miles was 13.6 miles on the actual device. I have reset the speed/cadence sensor and both red and green lights have appeared as normal. As well as this, i have checked the sensor alignment with the spoke magnet and it is correct, giving a green light after each pass. The cadence sensor produces a red light after each pass also. The auto resume feature works fine too, as does the pairing of the device with my edge 800. Any clues as to what the cause may be? Thanks in advance.
Steve
Steve
0
Comments
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Wheel size setting?I'm sorry you don't believe in miracles0
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If you have an 800 why are you using a speed sensor? Just use the gps.0
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Stupid question, but did you try a new battery (and insert it the wrong way first to reset the GSC10)?0
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Dippydog2 wrote:If you have an 800 why are you using a speed sensor? Just use the gps.
It's more accurate as the GPS will give you a straight line distance whereas the speed sensor works on the number of wheel rotations and therefore when cycling over hills (I live in north devon), is more accurate0 -
DCDB wrote:Stupid question, but did you try a new battery (and insert it the wrong way first to reset the GSC10)?
I haven't changed the battery because it's only 5 months old and has a lot less hours on it than would be needed to drain the battery. Also, it syncs with the device perfectly well, as well as giving the correct lights when the spoke magnet and cadence sensor pass the main body0 -
had similar thing happen to mine a while back, would work fine for 3 or 4mins after pairing but then drop off to next to nothing. Rang Garmin customer support and they sent a new out to me without needing to ask.0
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Rather than starting a new thread -
How do you know if your speed field is calculated by the GPS or the GSC thing...?0 -
I had exactly the same issue. only a few months old, paired fine, but said I was doing 5mph when I was clearly doing 20mph or more (even on downhills).Steve_kay wrote:DCDB wrote:Stupid question, but did you try a new battery (and insert it the wrong way first to reset the GSC10)?
I haven't changed the battery because it's only 5 months old and has a lot less hours on it than would be needed to drain the battery. Also, it syncs with the device perfectly well, as well as giving the correct lights when the spoke magnet and cadence sensor pass the main body
I changed the battery and it was fine.0 -
Interesting comment, I would like to know why you think that. If you look this topic up on the internet there is a vast body of thought that considers the wheel sensor with magnet to be much more inaccurate. There are problems with the accuracy of the wheel diameter and other issues.DiscoBoy wrote:Dippydog2 wrote:If you have an 800 why are you using a speed sensor? Just use the gps.
A speed sensor updates the time more frequently, and is more accurate. Also, it is also a cadence sensor.
Either way, the Garmin takes a data point every second.
And, if you upload the data to Strava is does some massaging anyway.
My Garmin cadence sensor is one of the new ones. Cadence only. No silly arm, no silly magnet and the speed readings are more than accurate enough for me.0 -
Thanks elbow. Much appreciated. I'll give that a try later and hopefully it'll resolve things. Seems a bit odd that it would drain so quickly0
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There are problems with the accuracy of the wheel diameter and other issues.
The Edge 800 has 2 ways of measuring the diameter. Either automatically or you can manually enter it. I know that the GPS is probably more accurate for speed readings however the distance is another story as i mentioned above about gradients0 -
Certainly try replacing the battery.
I'm not sure the GSC10 will give any better results than GPS once uploaded, but certainly it will give more consistent/accurate results during the ride, since GPS signal can easily be disturbed.WyndyMilla Massive Attack | Rourke 953 | Condor Italia 531 Pro | Boardman CX Pro | DT Swiss RR440 Tubeless Wheels
Find me on Strava0 -
Steve_kay wrote:Thanks elbow. Much appreciated. I'll give that a try later and hopefully it'll resolve things. Seems a bit odd that it would drain so quickly
The battery wasn't necessarily new when you started using it, the battery could have been sat in there for years on a shelf somewhere.0 -
Dippydog2 wrote:
Interesting comment, I would like to know why you think that. If you look this topic up on the internet there is a vast body of thought that considers the wheel sensor with magnet to be much more inaccurate. There are problems with the accuracy of the wheel diameter and other issues.DiscoBoy wrote:Dippydog2 wrote:If you have an 800 why are you using a speed sensor? Just use the gps.
A speed sensor updates the time more frequently, and is more accurate. Also, it is also a cadence sensor.
Either way, the Garmin takes a data point every second.
And, if you upload the data to Strava is does some massaging anyway.
My Garmin cadence sensor is one of the new ones. Cadence only. No silly arm, no silly magnet and the speed readings are more than accurate enough for me.
I say that the accuracy is higher when using the speed sensor because the interval at which it updates the speed on your display is, on my 500 at least, noticeably shorter.Red bikes are the fastest.0 -
pirnie wrote:Steve_kay wrote:Thanks elbow. Much appreciated. I'll give that a try later and hopefully it'll resolve things. Seems a bit odd that it would drain so quickly
The battery wasn't necessarily new when you started using it, the battery could have been sat in there for years on a shelf somewhere.
Yeah that's a fair point. Hopefully when I replace it, it should last a lot longer. I may even replace my HRM battery while I'm at it0 -
My batteries are over 2 years old and still going...the GSC10s were sold a short while ago but HRM is still on its original battery since May 2012.WyndyMilla Massive Attack | Rourke 953 | Condor Italia 531 Pro | Boardman CX Pro | DT Swiss RR440 Tubeless Wheels
Find me on Strava0 -
It sounds like I've just been unlucky with mine. The HRM hasn't put a foot wrong yet. Saying that, neither had the speed sensor until yesterday0
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If your HRM puts a foot wrong, its attached in the wrong place ;-)WyndyMilla Massive Attack | Rourke 953 | Condor Italia 531 Pro | Boardman CX Pro | DT Swiss RR440 Tubeless Wheels
Find me on Strava0 -
Just under the man boobs ;-) Then wet the pads with a bit of spit on on your thumbs.WyndyMilla Massive Attack | Rourke 953 | Condor Italia 531 Pro | Boardman CX Pro | DT Swiss RR440 Tubeless Wheels
Find me on Strava0 -
DiscoBoy wrote:Dippydog2 wrote:
Interesting comment, I would like to know why you think that. If you look this topic up on the internet there is a vast body of thought that considers the wheel sensor with magnet to be much more inaccurate. There are problems with the accuracy of the wheel diameter and other issues.DiscoBoy wrote:Dippydog2 wrote:If you have an 800 why are you using a speed sensor? Just use the gps.
A speed sensor updates the time more frequently, and is more accurate. Also, it is also a cadence sensor.
Either way, the Garmin takes a data point every second.
And, if you upload the data to Strava is does some massaging anyway.
My Garmin cadence sensor is one of the new ones. Cadence only. No silly arm, no silly magnet and the speed readings are more than accurate enough for me.
I say that the accuracy is higher when using the speed sensor because the interval at which it updates the speed on your display is, on my 500 at least, noticeably shorter.
Ah, understood. It's every second on the 800.0 -
It could be the battery - it may not have had full charge when you received it.
The 'reed switch' in these is notoriously frail though - mine has stopped registering every revolution - reads the correct speed most of the time but every few minutes skips a rotation or even several, sometimes making it autopause while going along the road! It seems that they get damaged or moisture gets in. Garmin seem good about replacing them but mine is two years or so old - so havent contacted them yet, gone back to GPS for speed.
The wheel sensor does not normally use a manually set circumference (although you can do that if you choose to), what it does is measure a distance using the GPS, count the revolutions over that distance and work out the effective circumference. How often it does this is unclear but this means it automatically adjusts for different wheels/tyres etc automatically.
It is more accurate than GPS because GPS is only accurate to within a few feet so it constantly just a little bit out, it also samples on periodic positions to this means that if you turned a corner it will cut the corner if its sampling was only at the start and end. Wheel sensor also does not need altitude correction etc and has no problems if going under trees or where GPS signal is poor.
Using the wheel sensor it also autopauses and resumes more quickly - presumably when using GPS the resume doesnt see you are moving until the next sample time and even then waits for another sample to make sure it wasnt just GPS drift or inaccuracy.0 -
If anyone wants a slightly used GSC10 let me know. I have two!
Clearly they are now surplus to requirements.0 -
I've just changed the battery and it's made no difference whatsoever. The edge 800 is still only showing between 3-5 mph no matter what speed I'm going. Looks like it's going back to Garmin0
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Have you tried re-positioning the speed sensor? I had a similar problem a month or so ago. I think the wheel magnet was ever so slightly out of line - re-positioned bot and has been working fine since.0
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Yeah I repositioned it a few times. I've also just noticed that the green light doesn't always flash when the magnet goes past. It's very temperamental. Looks faulty. The cadence sensor (red light) works every time.0
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<Cough>Colinthecop wrote:How do you know if your speed field is calculated by the GPS or the GSC thing...?0
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Colinthecop wrote:<Cough>Colinthecop wrote:How do you know if your speed field is calculated by the GPS or the GSC thing...?
Lift up your back wheel and spin it, if the speed reads zero it's from the GPS, if not it's from the sensor0
