Garmin Edge 500 and Courses

Cookie_Monster

So created a route on ridewithgps.com and loaded into the 500 to see what the story was with it.

Not too impressed tbh, the route got lost several times, even had to stop once to check the phone maps to confirm the turn I took was correct despite the edge saying I went off course. Even on rather straight sections of road with no others close by it lost the course a couple of times.

Corners and Junctions always came 30-70 metres earlier than the course recognised too, and when I checked the gps accuracy it was within 3-5m so no error down to that. Not idea, having to keep a constant check on it rather than wait for the beeps. All well and good in this case as it was on familiar roads but I don't think I'll be relying on it too much on longer spins outside the area.

It missed a couple of junctions too.

So I'm wondering:

1) Maybe some of the errors are due to the ridewithgps data against actual gps device readings?
2) If I turn the recorded route today into a course would it be more accurate than the map data course, I imagine it would be
3) Any other way to make it more accurate, better websites etc

DirkVoodoo

More to do with the maps than the garmin I'd say, try creating a route from a previous ride and see if it is any better.

Tau

I've found this website quite good:

http://www.bikeroutetoaster.com/Course.aspx

smacl

I'd guess it's a grid transformation error occurring when you transfer from the PC software to the Garmin. I haven't used the Edge 500, but on my old 76CS you can transfer data in either projected grid coordinates (x,y,z) or WGS 84 geodetic coordinates (lat, long, height). Using WGS84 will remove most grid transformation and projection problems.

You can read WGS84 coordinates from google earth. Might be worth zooming into a known point on the ground and comparing the Garmin position to the google earth position. I'd expect them to agree to ~10-20 metres.

CheGuedara

@ Cookie Monster - actually found something similar myself after making a course on Garmin Connect itself (which on the whole is OK for course creation BTW).

The 'trail of bread crumbs' line indicating the route was more or less accurate (nothing as noticeable as junctions arriving earlier than expected) but I got some intermittent off course warnings on some courses.

Have found that using the saved ride as a course next time round it works pretty much perfectly. I suspect the initial course was maps closer to the center of the road and that's what caused the dropping out of course, it's just my theory though.

Cookie_Monster

Will give it a go tomorrow on the spin today mapped as the course.

Doesn't solve the problem with non recognition of junctions though

I wonder if this is caused by something else though. Non recognition only happened twice, both where the road I was on was named the same as the road after the junction.

It happens a lot over here:

For example:

If I am travelling from 6ocklock towards 12 on "A street", despite the 6-12 road being the main, "A street" will turn left and continue towards 9oclock while the 12 road will be called "B street". Maybe from the mapping website the export file does not recognise the turn from the data due to the similar name...

Mr. Grieves

It sounds like the map data is off. Does ridewithgps use Google maps data? On Google maps, if you look at satellite view, you'll sometimes see that a marked road doesn't line up with the ariel photo, maybe running parallel to it 50m away. Can you see anything like this at the problem spots?

ashleey

I have had very similar problems including lockups mid ride requiring a 4 button reset. To be honest the best way to use a course is to use garmin connect or training centre from a previous ride. As was said earlier 'the garmin is good for telling you where to go when you have already been there but not much good for telling you where you need to go when you're lost'! It's still a great piece of equipment though.

seve65

i think ridewithgps does use the google maps data, which isnt the best, its missing several roads around cork and some sections for example, and is quite often not the same contour as the road.

But i have used the courses from ridewithgps, and it works okish for me... It does tell me quite a lot I'm off course on a completely straight road out in the open and the turnings can be a good few metres out so its easy to overshoot in the wrong direction at say a Y junction in the middle of nowhere. But, easiest thing I find is just watch to see how far off course you go, if it keeps going up, turn around and go back ! Alternatively, navigate by the contours of the land ! What would be useful ( and perhaps there is a way to do this), is to force the garmin to zoom out a bit to give a slightly better perspective of where you have just been and are going; when its drilled right down which it is most of the time that doesnt help much when trying to get some perspective.

Cookie_Monster

so used the data from yesterdays spin to programme the course directly on the device. No beeps or arrows for turns at all...

not great.

CheGuedara

Cookie_Monster wrote: »

so used the data from yesterdays spin to programme the course directly on the device. No beeps or arrows for turns at all...

not great.

FWIW - the only guidance I've known mine to provide on a course is the trail of bread crumbs guide, never been beeped or shown an arrow to indicate a junction ahead, I don't think that's part of the Edge 500 functionality. Only beep warnings I get are if I'm off course.

If you're ever unsure of the Edge 500 device refer to DCRainmakers blog - he does an excellent review of it and pretty much picks out every conceivable detail of what it can and can't do, updating as Garmin adds/changes features.