gitsome wrote:Garmin GPS sucks
I must say I was in the market for a GPS computer recently, checked out Garmin 800 series (too big) and 500 series. When I looked at the 510 gps readings from a friends mountainbike route I was AMAZED at the INACCURACY of it!!! He did 4 loops of the exact same trail (single-track no less) for a race. When we looked at the plotted lines of the "mapping" function --- Hoolly COW! They were ALL OFF by no LESS than 50-200 feet per line!!!! It was 4 distinct lines that varied completely fro each other despite the trail being less than a foot wide!!! What a piece of shittte!
I would never buy a GPS computer now given what I saw. Save the money, buy a nice Assos jacket or a new set pedals or a few bottle of great wine. SCREW Garmin
gitsome wrote:These units are inaccurate even when they have a full signal (and thus will not blip like strava when it losses signal) and so you cannot really trust the data you get even when they seem to be working properly. They will look like they had full signal (and they did) and put forth data but it is not accurate and the margin by which I found it to be off (and others have observed) do not make me confident it is worth the $200-500 they cost, wish they did.
I thinnk GPS and cell are great technologies when you can afford to be off by 200 ft for general purposes but for cycling they are not precise enough. I wonder if its a national security offset. Civilian GPS used to have a programmed bug where it would "blip"and be purposely off-set so that foreign (navies mostly) forces could not intercept it and utilize it when the US was the leading power in this respect. Sometime Around late 90s the GPS "wobble" was removed but I wonder if this fuzzy accuracy was instituted in its place for the same reason. Sat this time Russian GPS (Glasnat or whatever I guess) came online, but I don;t think Russian space technology has been worth a bottle of vodka since 1957.
You never even read the articles I linked to:
The tests were stark in their results: GPS/GLONASS dual-system antennas definitively offer a noticeable improvement in accuracy and performance. Urban environments are the true test of performance, and dual-system antennas are clearly superior... Nonetheless, the accuracy is extraordinary, considering how weak the signals are and the length they have traveled, picking up huge amounts of noise on their way to the small GPS antenna inside a vehicle, while moving with an obstructed view of the sky!http://electronicdesign.com/test-amp-measurement/real-world-drive-tests-declare-verdict-gpsglonass
gitsome wrote:And when do you think the Glonass satellites were launched??? Genius, thats the whole point. Its a shitty system that hasn't worked since it was launched 6 years ago. The last 5 rockets have all exploded on the launchpad. What do you think?
Do you still believe GLONASS was launched 6 years ago? I bet you won't answer this.
gitsome wrote:Its amazing how stubborn people are once they've spent money they can't be objective and rather bury heads deeper in the sand.
Stubborn about what? That we realize the abilities and limitations of GPS?
gitsome wrote:And this article itself states that you need UNOBSCURED SIGNAL FROM AT LEAST 4 SATELLITES for it tot work and they had to go to some remote location to achieve this, otherwise the signals are al too poor to be considered for the test. So lets see. Under remote, perfect conditions they work mostly, great test.
Can you finally admit that getting a lock on 4 satellites isn't that big of a deal?
gitsome wrote:And yet they were all off by 50-200 ft in a well-covered area, so if you like your data to be that far off go for it. But that can easily be the difference between 1-5 mph or more, 1-10 miles distance, etc etc.
gitsome wrote:Yes, and even with a those sats it was still off by 14 at least. Thats my point, with that much deviation your data as far as mph will be off considerably too don't you get that?! Not to mention mapping etc. even with 14 ft of inaccuracy over a mile that will ad up to a considerable margin of error and then multiply that by 100 or whatever milage you do and that leaves you with a basically useless compilation of data.
Have you finally realize that you don't compound the GPS accuracy over the course of a bike ride, right? Just because it states a 14 ft accuracy doesn't mean over the course of a 3 hour bike ride that your computer is wrong by 10-15 miles and 3-4 mph. Math doesn't work that way.
If you read DCRainmaker you will see that the Garmin's are close to 99% accurate for distance/speed while road biking. That number drops to 97-98% when being used in a heavily wooded area with dense tree cover. Remember this was done with the older Edge 500/800 and not the newer versions.
As far as Glonass, it does't work well even with clear sky considering there is still at least 14 ft of error or more, and how often is sky perfectly clear? Would you just use it on perfect days then? Given your answer I guess you would. For my money I'd rather something better before I spent that much.
What do you mean GLONASS doesn't work well?
gitsome wrote:I don't remember, it was a few weeks ago and not my unit, I can ask next time I see the person who used it. I all get any pertinent info when I see him.
Have you gotten the rest of the info? I know you said you thought it was on 1 second recording. Have you asked what firmware version it was running. Was it on GPS+GLONASS or just GPS? What kind of readings did he get before you headed into the heavily wooded area?
gitsome wrote:None of those would be good to rely on a 510 or 810 if you care about mph etc in the minute detail a cyclist demands. If youre speed is off by more than 2 or 3 mph what is the poiunt of spending all that money>? If youre routes are off by 200 ft, then you cant really chart a good map of trails, etc etc
Minute detail? What do you mean by that. So instead of knowing I average 24.6 mph for my ride, knowing that I did 24.6178912 mph is the exact minute detail I demand as a cyclist? Since when have we been training by mph? Watts is all that matters. If not watts, then HR. Not mph.
I bet a GPS is more accurate in terms of speed that a speed sensor on the rear wheel that doesn't take into affect tire size, tire wear and possible irregular calibration. GPS is as accurate as they come.
gitsome wrote:Since nobody actually reads what I wrote I'm done wasting my time. Go ahead and twist my words around, have fun pat yourselves on the back. You're Garmins still suck and you can't stand to hear it.
Sounds more like trolling than anything else.
gitsome wrote:All I've done is make a point and clarify it over and over because it gets twisted around constantly and thrown in my face, what a lame thread.
It isn't get twisty. I am using exactly what you wrote. I am pointing out issues with what you wrote and refuting some of your claims. If you consider that being thrown in your face, so be it. If what you wrote was legit and actually constructive, I think this conversation would have gone a lot smoother instead of "Your Garmin sucks."
In terms of this whole MTB/dense tree cover/GPS thingy, if you read the article from the link provided earlier in the thread by another poster you will see other people (outside of WW and not connected to this debate) that have had very successful use with the Garmin 510 in densely covered areas.
My 510 displays accuracy of 10’ or less a high percentage of the time when road riding. I can’t say how much less, since the value is set with 10’ as a minimum, but it’s pegged on 10’ a lot of the time. I can’t recall a single disappointing road GPS track since I have been using the 510. While I still will do my manual splits for my most important climbs, I am finding that I am getting Strava data accurate enough for me to make valid comparisons. It is on the mountain bike, however, where the difference in accuracy between the 500 and 510 is quite dramatic. Typical 510 accuracy values are 15-20’, no matter what kind of cloud or tree cover I am under. I don’t believe I have ever seen a higher number than 30’, and I have been obtaining outstanding GPS data as a result.
What this boils down to is that if you use your Garmin on a mountain bike and want consistently reliable data, the 510 is the only way to go. If you only ride on the road, the increased accuracy is nice, but individual results can vary, and I know plenty of people who are happy with their 500. If it were me, knowing I was getting much more reliable and a higher level of GPS accuracy alone would justify a 510 for road only use. But what if we forget about GPS accuracy and mountain biking, how strongly would I recommend the 510 over the 500? Very, very strongly is my answer.http://tomsbicycleblog.blogspot.com/2013/09/faceoff-garmin-edge-510-vs-garmin-edge.html
"Marginal gains are the only gains when all that's left to gain is in the margins."