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So right now I use an iPhone for my GPS. I either throw it into a pocket or my camelback. I also use a $10 bike computer on the handlebar to get distance. Seems I'm duplicating effort here, and I've also been wanting to get a heart rate monitor for training.

Having said that, been thinking of a Forerunner 305 or Edge 500 as my GPS/bike/running solution. While I don't run too much, I wanted to have something for the times I do, and it seems the Forerunner is better served for that, but the Edge 500 can still work in a pinch (https://lh4.ggpht.com/_Wo8yCZ1eTVw/Syc4WxqV9DI/AAAAAAAAUHQ/oqS2ACl4cZ0/IMGP8420_thumb.jpg?imgmax=800)

Is the GPS sensor on the 500 that much better? Is the 305 GPS sensor going to be better then my iPhone? Am I "downgrading" by switching the iPhone to the 305? I'm not worried about the battery life, as 10 hrs will be good enough for me. I'm at 3-4hrs now with the iPhone and thats enough. Also, don't care about the power meter functionality of the 500.

The 305 is $170 with the heart rate strap, while the 500 is close to $300 after I buy the heart rate strap.

-Tom
 

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Disgruntled Peccary
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I have a 405, one of my buds has a 305 about the only accuracy issue I know of is altitude.. which sucks on every GPS I've ever used. Course, I live in an area without a lot of tree coverage, so YMMV in terms of reception... we've compared both to a handheld garmin (an etrex I think) as well.
 

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The GPS receiver on a modern dedicated GPS is going to be miles above what the iPhone uses. Apple uses outdated hardware for the GPS in the iphone because it's relatively cheap. they augment it with the cell towers to make it look like the gps works better than it does.

The only thing that might disappoint would be user interface on the Garmin compared to the flashy iPhone interface.

The Forerunner would be fine for your needs. those are built with a multisport audience in mind, especially running and cycling. I know a guy who uses one and he has no complaints about it.
 

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I have a 405, one of my buds has a 305 about the only accuracy issue I know of is altitude.. which sucks on every GPS I've ever used.
i use the foreunner 405. w/delorme pn-40. the edge 305 alltitude is good. I think the pn-40 altitude works but I really haven't compare it w/other devices yet. foreunner 405 good for recording, heart rate & speed. no topo or if you want to follow a route in the woods :madman:

here's a short ride captures w/delorme pn-40 there' elevation
http://www.everytrail.com/view_trip.php?trip_id=465573

here's saddle river loop recorded yesterday w/forunner 405

http://www.everytrail.com/view_trip.php?trip_id=466319

here's rea & saddle river recoded w/ edge 305
http://www.everytrail.com/view_trip.php?trip_id=437798

at the end of the day it's misleading w/foreunner 405 as it tells you total elevation gain

some one time me the device needs barometric pressure reading. just be careful if you use one that's off and then attempt a ride or race based on incorrect data :(
 

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Thanks to Nate I have been looking at my elevation my Edge 305 alot. Some things I learned. The barometric sensor is the most fragile part in the unit. I think this leads to most issues. Also it recalibrates with data from the GPS every 15 minutes. So for the best data you need to let it sit, on for 15 mins before you start recording data. This also allows for the temps become balanced. I understand that this process will get you a ~3% margin of error.
 

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jkmacman said:
some one time me the device needs barometric pressure reading.
That changes too with pressure changes, so even then not really a lock. Course, the best way to deal with it is to apply your track to an application that normalizes your altitudes against an actual map. Even with other GPS devices, the altitude varies quite a bit. This includes the etrex handhelds, and the colorado I've played with. It's just easier to notice IMO on a run or ride on the same trail/loop. BTW, I'd be happy with a +/- 50' deviation.. I've seen deviations of over 600' on the same run/ride ;)

edit: with the same device.. and multiple devices.. sufficeth to say.. GPS elevation tracking sucks. I've never seen one worth trusting, not only that.. but countless conversations yield the same result. No one trusts them.. :)
 

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I've seen deviations of over 600' on the same run/ride
here's my regular 18 mile road ride:

forerunner 405: Elevation Gain: 2,250 ft
https://connect.garmin.com/activity/14846667

edge 305: Elevation Gain: 1,642 ft
https://connect.garmin.com/activity/17283563

here the disparity is 600 ft more or less, this ride is along a steep cliff, palisades which may have a factor, in generl the 405 stinks for elevation


these rocks fell from the steep cliff above, may wreak havoc w/ gps?
 
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