TrojanHorse

I found one on ebay for crazy cheap (new in box, 216 for the whole kit... normally they're 350 so yeah, I was worried ha ha)

Anyway, the thing's great but it's goofy. it keeps auto-pausing in the middle of a ride. I was cruising around at about 17 mph on Tuesday and it kept pausing. what? I did change the auto pause to pause when I get below 1 mph but I'm going to turn off auto-pause if this keeps up.

Today, i went for a short post-lunch spin of not quite 6 miles just to get the rust off, and my phone GPS (all sports GPS app) says I went 5.88 miles. Garmin says I went 5.05 miles, that's a pretty large difference. It was locked on from minute 1 so there's no reason for that large of a discrepancy.

It also kept displaying the wrong speed - I'm going 19 down a slight hill and it would say I was going 0 for a second or two, or maybe 9 mph. Very disconcerting.

And then on my final hill of the day, a nice 15% grade according to the front of the display, it kept pausing even though I was managing about 7 mph up the hill.

Anybody have any idea what's going on? I have the cadence / speed transmitter installed and I had to kind of tilt it over to get the thing close enough to the crank to sense my cadence, which put the wheel sensor so close to the spokes that I had to flip the magnet around the other way. (the seat stays are curved a lot and run very close to the wheel)

except for inaccurate data, I love it.

I really want to use it in stead of my phone for a variety of reasons (battery being one of them, and my phone GPS receiver is sometimes sketchy)

Any tips or advice are welcome, thanks.

sstorkel

I don't have an Edge 500, but my 705 has several different modes for determining distance and speed. It's possible to tell the device to use only the speed sensor, combined with a wheel size that you enter manually. If the wheel size is incorrect, you'll see errors in both speed and distance traveled. In general, you should probably have the unit use GPS to determine distance and speed or you should make sure that the wheel size is set appropriately.

The Edge 705 also allows you to set the speed at which the unit considers you stopped. If that number is set too high, it might account for the auto-pausing.

My Edge 705 was also a bit flakey when I initially installed it. Turned out that the battery in the speed/cadence sensor needed to be replaced. If you press the test button on the speed/cadence sensor on don't see a consistent, visible light then the battery might need replacing.

TrojanHorse

Does your garmin have the same speed & cadence sensor (I think it's a GSC-10 or 1)?

I've been perusing the garmin site and it would appear there are plenty of problems.

I'll try the test light, thanks. I just noticed it also gave me a max cadence of 154 for my ride today... if I get up over 110 my butt bounces all over, so I'm pretty sure 154 is right out.

Rimmer

The auto pause has a delay, but it shouldn't do what you're describing. That and the inaccurate grade percentage I find kind of annoying. A 15% grade is pretty extreme.

Press the GSC-10 sensor button. Do the red and green LEDs blink when the magnets pass?

If you have your auto timer pause below 1mph, you might as well turn it off or increase it to something higher.

Go to Settings>About Edge

Which firmware version are you using? 2.8 is the latest.

Seve

Have you set a starting elevation point ?

[See Page 43 of the manual.]

Not sure if you have an ANT+™ speed and cadence sensor installed or not?

The unit is much more accurate with the sensors installed than simply relying upon GPS position points to calculate speed and distance.

bigfred 

Re: higher than expected cadence readings. Try not coasting with your left foot horizontal and trailing, where you're placing the left crank arm w/magnet next to the sensor.

TrojanHorse

I think the 15% might actually be close on my street, it's a nasty hill. Nasty! My actual drive way was closer to 24 degrees and I don't bother riding up it.

The sensor lights do light up when the magnet passes the sensor, but maybe 58 times out of the 60 before it turns off. I may need to spend some time trying to improve the layout but it's challenging with the shape of my chain stays. If the part that sticks out measured cadence and the built-in part measured the wheel magnet I'd be all set.

It looks like the auto-pause was automatic, so I changed it to 2 mph, guess I"ll be trying this again tomorrow to see what gives.

Firmware: 2.8. I updated it when I first set up the computer.

I have *not* set any elevation points yet, although the elevation in my results seems to match what my phone says and even changing it to elevation correction doesn't appear to change the results of the workout.

The wheel size was also set to auto so I changed that to 2096 for a 700c/23 tire, maybe that will help a little.

In the good news department, the actual track I rode was much better than what my phone came up with in terms of not riding off-road, so I have high hopes that once I figure out whatever issue I'm having I'll really like this thing.

Drew Eckhardt 

You're having problems with your GSC10. Maybe it's not installed quite right, maybe it's flaky.

GPS error adds up. I've gone about half a mile in 40 minutes on a trainer.

Turn off auto-pause. With it on you can't accurately capture the training stress of a ride.

Your favorite desktop (Golden Cheetah is free, runs on Windows/Mac/Linux) or web based software (connect.garmin.com, mapmyride.com, etc.) will give you a moving average speed for bragging rights or whatever (although it still varies too much based on traffic where you're not pedaling to approach a light or accelerate from a stop).

TrojanHorse

Alright, looks like the cadence sensor thing is somehow not functioning, I'll fiddle with it in the AM, maybe try a new battery for kicks too.

I'll try turning auto-pause off too.

sstorkel

Might not be a bad idea to take the GSC-10 off the bike and make sure everything works properly without it.

When you put the GSC-10 back on, the first thing to do is get the speed sensor working. Speed is more important than cadence. When placing the GSC-10, try to put it on the chainstay near the point where the crank arm is closest to the stay. Then place the cadence sensor on the crank arm.

If the cadence sensor doesn't trigger reliably, there are a couple of tricks you can try:

1) Put a piece of rubber of plastic between the cadence magnet and the crank arm, to push the cadence magnet closer to the frame. I cut up a piece of rubber that came with my Edge 705.

2) Stack another magnet on top of the first. Neodymium magnets work best. I used a spare speed or cadence sensor I had lying around from a previous computer. You can test the setup using just magnetic attraction to keep the two magnets in place. Once you're sure it works, you may want to glue the second magnet to the first to prevent it from getting lost.

If you're going to input the wheel size yourself, you owe it to yourself to measure the circumference of your actual wheel. I've never yet found a real-world tire that matched the values printed on a chart...

EGUNWT

I had lots of problems with the S/C sensor, I ended up just taking it off my bike.

Make sure you're running the latest firmware from Garmin. It should prompt you for that while you've got it syncing with their website.

Seattle Forrest

I have an Edge 800, and the cadence sensor. Mine also cuts out like that, eg I'm doing 30+ mph down a hill and it'll show my speed as zero for a few seconds, or even minutes. To fix the problem, I'm using GPS for speed and distance, not the sensor. The downside is every now and then it'll report thousands of miles, because it thinks I biked from Seattle to Mongolia back to Seattle, in a minute or two, but this type of problem happens much less often than the cadence sensor cutting out.

I've owned every Oregon unit Garmin made, and every one of them had some important problem. It culminated in one of them, advertised as submersible waterproof, not working after I hiked in a rainstorm. Garmin makes very mediocre products. I put the cadence sensor on twice, verifying that it's alined properly and reads out, and I've had three bike mechanics look it over and tweak it if necessary. It isn't on wrong, it just doesn't always work.

The reason yours is reporting 5 miles on a 6 mile ride is that yours wasn't working 1/6 of the time.

PS - My max cadence is 223 rpm on each and every ride, according to Garmin. What an amazing coincidence!!

paisan

I've had the opposite expriences with my 705. I have sensors on 3 different bikes and mine have been pretty reliable. The only time I had a random "seattle-mongolia-seattle" event was on a trip to northern PA. I was on one of my bikes that doesn't have a sensor and the unit lost the GPS signal, it did a sort of deadreckon track using my last known speed, heading while the signal was lost but then shot back to my actual position once the signal was regained. None of that was noticeable while I was riding and I didn't catch it until I downloaded the data after the fact.

The only thing I can recommend is to go to the Garmin forums and see what other users are saying. If there's a firmware/hardware issue there's a much greater chance of it coming up in those forums vs this one where there is a small number of garmin users.

TrojanHorse

223 max cadence! Man, mine was only 150. I better get spinning!

The consensus on the garmin forums seems to be that the speed and cadence sensor isn't very good, unfortunately, since it costs more than some standalone bike computers. I'm going to try the reversed battery-reset trick and then slap on an additional magnet to the crank so that maybe I can rotate the sensor more vertical and hopefully those two things combined with maybe a new battery will do the trick.

I'm ok with the occasional Los Angeles - Hawaii leg, it happens with all GPS units and probably can't be avoided. You might think the unit would discard an update that radically bad though. Interestingly, I had many, many tracks on a single 45 mile ride that were out in the middle of the Pacific back when I had a blackberry. I thought I would just edit the track to get rid of the offending points, but there were thousands.

Seattle Forrest

Sounds like it's too late for this advice to help you ... but Amazon sells them for about 1/3 what my LBS does.

YES!!! Garmin took the time to write a "virtual training buddy" program for their unit. They could easily have spent a minute fraction of that time writing a "sanity check" function into the unit that compares the current GPS reading against the last few of them in the track log, and ignores anything where a cyclist breaks the sound barrier. I make computer software for a living, and I know this isn't hard to do. I even wrote an app that can remove the faulty data from my track logs because of this problem.

TrojanHorse

SF - it's been on my Amazon wish list for a long time... but they're roughly 350-370 depending on the color scheme even at amazon.

I got mine brand new on fleabay for 219 shipped. (I'm talking about the one with the flawed speed sensor and the HR monitor)

Same with the speed - I'm going 19, 19, 19, 0, 19, 19, 19.... c'mon. (NB: downhill speeds admitted in public only thanks.)

sstorkel

Agree. I have an Edge 705 and several different GSC-10 sensors on different bikes and haven't had any major problems with them.

I've only had one occasion where the GPS glitched: it was on an organized ride and I was quite amused to point out to my friends that my average speed was over 300mph and they needed to pick-up the pace if they wanted to keep up This seemed to be a common complaint with whatever version of the firmware I had installed at the time. After I updated to the latest firmware, I didn't have the problem again...

magohn

+1 - Close to 3000 miles on my 705 and Im yet to have a "glitch". Rock-sold reliability and I have ridden the same training runs many, many times and the reported speeds and distances are spot on. I love my 705.

TrojanHorse

Well, screw you guys with the 705! But seriously, why is the same GSC-10 reliable on your GPS and not mine? Weird.

Update: I went to radio shack and bought a variety of magnets, none of them did me any good. I pillaged the cadence sensor magnet from another bike computer, glued it on top of my existing crank magnet to give it more "reach" and reoriented the GSC-10 into a more vertical alignment. This allows me to put the wheel magnet on the way it's supposed to be put on and it seems to be triggering the sensor every rotation now.

We'll see tomorrow, got a nice little solo ride planned on the SART. Maybe I'll run across Beanz; usually I get up too early.

sstorkel

There are likely two causes of problems: 1) placement of the GSC-10 and, 2) bugs in the firmware of your Edge 500.

I have GSC-10s installed on my road and touring bikes. The chainstays are relatively straight and the Q-factor of my cranks is pretty narrow, so everything lines up nicely as far as the GSC-10 is concerned. Sounds like placement on your bike may be more difficult, but it seems like you're on the right track to fixing it.

Garmin is also pretty good at releasing buggy firmware. I waited at least 18 months before buying my Edge 705, because it seemed like early adopters were having a number of problems. By the time I bought, the majority of the worst problems were fixed, though to this day the unit will occasionally stop displaying the gradient in the middle of a ride... I haven't followed the Edge 500 and Edge 800, so I don't have any idea if there are firmware problems with it.

RollCNY

I have Edge 500 and GSC-10, and have had only a few issues:

When mine Auto-pauses all the time - data is full.. delete all of the training history from the previous user. It gives no indication when its memory is full, and starts acting screwy.

When starting up, does not always pick up the GSC on the correct bike. Is a total pain at events with other ANT+ devices, or on group rides. On Mup rides, I can tell you the heart rate of everyone around me.

The only times I have gotten screwy speed or position data is when I have used it without the GSC-10. In tree covered areas the signal pops out, speed goes nuts, and then comes back in to reasonable.

Never had a cadence issue.

TrojanHorse

Well, I fiddled with the GSC-10 yesterday and ended up gluing an additional cadence sensor magnet from an old computer to the existing magnet. That let me straighten out the GSC-10 (make it sit nearly vertical on the chain stay) and today - I had zero problems with speed and cadence. (Well, after I remembered to re-pair it I had no problems). Thanks for the suggestion sstorkel!

SO it would appear that my garmin is functioning correctly for now, and that's dang nice. I really like it.

The only remaining quirk, and it's probably my fault, is that I seem to end up with a data point at my house for rides that start way far away (if I drive to one, let's say). I'm positive I hit the reset button this morning after a hike with the kids but that data was right there with my ride data from later in the day. The instructions just say hold "reset" to reset the timer and save your data, which is what I did. I'm sure I'll get the hang of it eventually.

I'll have to remember the data full issue - I don't see any reason to store every ride I've ever done on it, that's for sure.

bigfred 

"reset" doesn't clear the memory. It does signify the difference between one timed event and another. Whereby allowing you to start and stop the timer during a timed event. Does that make sense?

sinclac

And the when he stops at a stop sign or what ever it keeps running (which means inaccurate data)

Leave your auto pause on.

sstorkel

It depends on what you're trying to capture: if you want to be able to show your buddies the highest average speed possible, then leave auto-pause on. Heck, set it auto-pause to 20mph; then you'll look really fast!

If you want an accurate picture of the work you're really doing, turn auto-pause off. Yes, it will bring your average speed down but it should: you're not doing work when you're stopped at a stop sign, buying Gatorade at the corner store, or pretending to fiddle around with the stuff in your seat wedge. You'll get a better picture of your average power output, average heart rate, and pace if you don't enable the auto-pause feature...