# GPS Recievers



## drgonzo (Apr 13, 2006)

I'm trying to find out info on GPS units, as I'd like to be able to make some trail maps. I'm intrested in programming and I think it would be really cool to be able to overlay trail data on google maps or maybe some topo ones.

Anyway, I don't know much about the technology (other than it's badass) and I'm curious if anybody else has units that they strap to their handlebars. Obviously as far as getting lost in the woods goes it's totally worth having a navigation device, but is it more of a novelty or are these things really useful? I know garmin makes some specifically designed for bike use, but I don't like the small screens and lack of map information.










One thing I'd also reallllly like to have in a reciever is bluetooth connectivity. I don't have any money for one of these now so it's all a pipedream. It's more fun shopping for stuff like this when you're not actually buying it anyway. Pshh... who needs money


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## wizzells (May 1, 2006)

Im using a Garmin Legend C, and I love the thing for navigation/speedometer/mapping capabilities. I have a handlebar mount on my bike and use the thing just about every time I go out. One thing to note, not all units are able to receive a signal in really heavy tree cover since they esentially need to "see" the sky for a signal. That being said, Ive never had a problem with mine receiving a signal in the woods, so I havent really had any concern for this problem. I also have a topo map set that I use and it shows just about everything offroad including ponds, rivers, elevation changes, and most roads. Ive had the unit about 1 year and am still realizing all of its abilities.


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## SwissBuster (Jan 19, 2004)

*Garmin Forrunner here.*

The forerunner (actually, most GPS units) records an electronic trail of where you have been, so can be used to download the data you get home. You can use this to make your maps on GoogleEarth or using OziExplorer (or other software). The Foreunner has a wristwatch format, but I usually attach it to the handlebars when riding. I might upgrade to the foretrex 205 model soon.

As far a navigation goes, any GPS can be useful but most 'experts' I have read about suggest it will not replace a good topo map. I don't use mine for navigation, and personally don't have much value for the 'map' features on the GPS itself - if I needed to read a map I would want a good paper one!

You're right about the technology: it's badass.


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## bvibert (Mar 30, 2006)

Check out the folks over at *Crankfire*. They do exactly what you're talking about. Its a pretty cool site and the admin has some pretty neat stuff going on with the maps and such. They've got a pretty good collection of trails in NE USA, and they seem to be adding to them frequently.


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## drgonzo (Apr 13, 2006)

SwissBuster said:


> The forerunner (actually, most GPS units) records an electronic trail of where you have been, so can be used to download the data you get home.


I know garmin lists some of their handheld units as just for location (i.e. just provides lon. and lat., compass heading, etc) and they have a seperate section for the mapping stuff. I think you're correct, but I would hate to pony up for one of these things and find out I can't get any data out of it :mad2:



> As far a navigation goes, any GPS can be useful but most 'experts' I have read about suggest it will not replace a good topo map.


Map and compass to the rescue! The eTrex Legend looks suited to what I want to do, the only thing that I'm not sure about is some people say the maps it comes with are crap. I saw on the garmin website they sell topo maps you can load onto the gps, but $100 dollars?! Are you f'in kidding me? I'd pay $20-30 bucks for ONE of the regions they include in the package. THAT'S HIGHWAY ROBBERY YOU BASTARDS!


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## Braunstein Freres (Nov 2, 2004)

drgonzo said:


> I'm trying to find out info on GPS units, as I'd like to be able to make some trail maps. I'm intrested in programming and I think it would be really cool to be able to overlay trail data on google maps or maybe some topo ones.
> 
> Anyway, I don't know much about the technology (other than it's badass) and I'm curious if anybody else has units that they strap to their handlebars. Obviously as far as getting lost in the woods goes it's totally worth having a navigation device, but is it more of a novelty or are these things really useful? I know garmin makes some specifically designed for bike use, but I don't like the small screens and lack of map information.
> 
> ...


I have the Garmin map60cs and I love it. Rarely do I lose a satelite and it has more features than I know what to do with! I actually wrote a user's comparison a while back. It is a somewhat limted comparison, but maybe it'll help a bit.
https://www.mountainbiketales.com/articles/noreaster2.htm

Also, as these things are technology-based I'm sure it's out of date.


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## roadiegonebad (Jan 31, 2004)

For mapping I don't think you'd want that Edge... that's really just a supercharged cyclocomputer. Yeah it can do candence, HR, and other neato fitness things and has the more sensitive SIRF chip, but the dealkiller for me was its rechargeable battery. Also, a number of minor glitches with it have been reported on the roadie site. Just got a Vista Cx, and it seems to be pretty good for my needs although I haven't gotten any mapping software yet (still reading Redwood Biker's book). I would guess that Garmin might update the chip in the next year or two, so waiting might not be a bad thing.


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## swampmonster (Apr 20, 2006)

GPS... I have a few my, old Stand by is a Garmin 12xl, I also have a Garmin V, 76cs+, Trimble GeoExplorer, and my newest one on order is the Garmin M5 PDA/GPS in one, and it runs on Windows CE...so far teh 76 is my fav, it can do it all but the old 12xl just will not die. The problem is finding good software that will let you do what you are wanting to do. I am still working to find one I like


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## Braunstein Freres (Nov 2, 2004)

SwissBuster said:


> The forerunner (actually, most GPS units) records an electronic trail of where you have been, so can be used to download the data you get home. You can use this to make your maps on GoogleEarth or using OziExplorer (or other software). The Foreunner has a wristwatch format, but I usually attach it to the handlebars when riding. I might upgrade to the foretrex 205 model soon.
> 
> As far a navigation goes, any GPS can be useful but most 'experts' I have read about suggest it will not replace a good topo map. I don't use mine for navigation, and personally don't have much value for the 'map' features on the GPS itself - if I needed to read a map I would want a good paper one!
> 
> You're right about the technology: it's badass.


Googlearth looks cool-thanks for the enlightenment! I also have little use for the naviagtion features of my GPS. The first time I went out with it I relied on it completely and that's as lost as I've ever been. USGS maps are the way to go and relatively cheap.


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## Stuart B (Mar 21, 2005)

Garmin Foretrex 201 here...wouldn't be without now.

Stu


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## Nathan Cloud (Jul 18, 2005)

bvibert said:


> Check out the folks over at *Crankfire*. They do exactly what you're talking about. Its a pretty cool site and the admin has some pretty neat stuff going on with the maps and such. They've got a pretty good collection of trails in NE USA, and they seem to be adding to them frequently.


Thanks :blush2:

And any and all out there with a GPS is welcome (urged? begged?) to join up and contribute to the community 

Otherwise, personally, I don't own any gps units that have anything more then road basemaps (have not dropped the coin for one with topo maps support) - but using them to navigate unfamiliar places and posted loops is a great thing (in my opinion). And never being lost is kinda nice as well. Something about hitting a good loop at a new place the first time out seems to beat the potential for exploring lots of bad trails and leaving disappointed?

Otherwise, I would not really recommend mounting the gps to your handlebars - its distracting, not necesarily secure, and puts your gps in a prime place for damage. Not to mention all the vibration could do some damage to the unit (but thats more or less hear-say). I tuck mine so it sticks out of the mesh of my camelbak - while it is not exactly accessible while riding, its out of the way and somewhat "safe". Of course this is all preference, but most people i know that went the handlebar route, have since abandoned it.

As far as units go, I hear decent things about the Edges, but there are lots of other (cheaper) options out there. Check out the Magellan explorist 210 - you can pick one up (after rebate) at amazon right now for $115ish. Its a nice unit. Otherwise, just make sure it has pc connectivity 

Then download Topofusion and life will be good.


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## Ultra Magnus (Jan 13, 2004)

I've got the forerunner 201, had it for a couple of years now (got it for xmas one year, '03 or '04, don't remember), and I like it. I strap it to my downtube for now, but I've finally ordered the handbar bracket, should be here next week. Right after I bought it the 301 came out with HR functions so I was ticked off a bit, but it was still really expensive, twice what I got the 201 for at Target ($125, on sale from $150). I occasionaly lose the satelite signal but only for a few seconds at a time, and I think it's due to eihter me or my top tube momentarily being in the way of the satelite. I'm also upgrading my google earth this week to start doing some mapping. I tried out a couple of those shareware programs but they are a bit slow and cumbersome. Google rocks!

All that said, I'm going to get one of the edge models next, at least with the HR, maybe both HR and Cad. but Cad. isn't that important to me.

BM


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## rcharrette (Dec 14, 2005)

*Garmin 205/305*

I e-mailed Garmin about this and got no response, maybe someone here knows. Is it possible to map out a route on your computer with waypoints then upload it to the 205 or 305? I do this all the time right now with my E-Trex Vista. It's great to sit and home, look at a Topo on the computer and just put a route together!
Thanks!


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## Ultra Magnus (Jan 13, 2004)

As I understand, the edge and forerunner models do not let yuo upload map information to them, and imo, the screens are too small and too low resolution to make any sense of map data. At last wtihe the forerunner, and probabluy the edge models, you can't pan the map view around anyway (of where you've been).

BM


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## rcharrette (Dec 14, 2005)

Yea, I'm not really interested in "looking" at map's on there. Just want to be able to know the small cut off trail I saw on the map with my computer (and dropped in as a way point) is comming up in 100 yards or whatever.


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## Ultra Magnus (Jan 13, 2004)

You can manually enter waypoints though, and on the "map" screen you would see them coming up +/- some degree of error. That would be handy, to mark locaitons of junctions or forks in the trail that might otherwise be easy to miss. I know on a lot of th trails I ride, the singltrack sections branch off the main roads and are hard to find, sometimes.

BM


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## dkr92886 (Apr 29, 2004)

*Forerunner 301*

FYI

REI has the Forerunner 301 on sale for $149.99. On sale until May 14th.


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## drgonzo (Apr 13, 2006)

After some looking around, I keep coming back to the Garmin eTrex Legend.










The price seems to hover around a little over a hundred bucks, very in my price range. It also has mapping capabilities which is what I'm really after. Has anybody bought/used this one?

EDIT:

Also, a lot of people I talk to about this complain about how these devices don't work good in the woods under a canopy, pretty much where I do most of my riding. I would like to be able to just drop it in my camelbak so I can look at it when I stop cause I realize I'm lost, but I also hear that you can't put these in bags? How about if there's only one layer of fabric between the gps and the sky (i.e. an outside pocket)?


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## dan0 (Oct 12, 2005)

rcharrette said:


> I e-mailed Garmin about this and got no response, maybe someone here knows. Is it possible to map out a route on your computer with waypoints then upload it to the 205 or 305? I do this all the time right now with my E-Trex Vista. It's great to sit and home, look at a Topo on the computer and just put a route together!
> Thanks!


no, the 205/305 dont display maps, they display a trail so you can upload a trail (garmin maps only) I sent mine back and got a gpsmap 60gsx instead because I wanted the sirf antenae. The gsx will display maps etc. I picked up a camelback phone pocket to hold the unit up front so I can hit mark anytime. this gps is the best. You can mount it on the handlebars if you dare. I also got the car kit and it came with city streets ( north america complete) with the car kit it will guide you on the road and I also loaded the topo maps so it will guide you off road too. it uses the trans flash memory chip (I got the 1 gig) which holds more maps tah I will ever need.


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## dan0 (Oct 12, 2005)

drgonzo said:


> After some looking around, I keep coming back to the Garmin eTrex Legend.
> 
> 
> 
> ...


again, the NEW gps map 60 series has the sirf antenae that will work under cloudy, forest, fabric etc. the 205/305 also have that antenae but the mapping view is non existant


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## barber (Apr 28, 2006)

*garmin sucks, but GPS rocks*

The Garmin is okay, but it is WAAAAAAY overpriced for something with no color. I could get a nice automobile GPS unit for that price which would have more features that the Garmin doesn't have, such as 3-d mapping, color screen, voice turn-by-turn directions, higher resolution, etc etc.


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## Whiffle (May 2, 2006)

I've got a magellan meridian, I can strap it to the side of my backpack in its zipped up case and it'll get a decent enough signal to make a map. I've thought about a handlebar mount for it but i'm afraid of crashing and destroying my gps, i think its safer on the backpack than on the handlebar.

As for making maps from the data, some of them can save to a flash card (mine can save to a SD card), which is a much faster way to get data than to upload it with the serial cable. Heere is kind of a nice howto on making photo maps:

http://www.engadget.com/2004/04/23/pts-how-to-fridays-using-a-gps-watch-xml-and-satellite/

It uses a program called USAPhotoMaps, which is free. I've made a couple but didn't really have any use for them so they got deleted. This post has sparked my interest so i might play with it before i go to bed...


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## hugh088 (Feb 1, 2004)

As one RI guy to another I can give you some info on how that unit works the great MTB'ing state of RI. In short pretty good. In the summer you will likely lose some signal while riding under heavy cover. I usually make a track when I ride and will get straight lines on the track for maybe 10% of the ride. This will usually not effect the track much when you plot it. I can always get a signal when I stop and check where I am or to mark a way point. Even in heavy cover, stopping allows enough weak signals to be seen by the unit to decide that it can give you a position and an error circle. As for carrying it, I have a Garmin soft case that has a plastic window in it. I attached this to the shoulder of my camelback so that it points up while riding. If you ever get to Big River be sure to carry your GPS, it's easy to get lost there. Use the track feature and plot it to USAPhotoMaps. Plot it on the maps not the photos for ease of use. Email me at [email protected] and I'll send you a copy of some plots I have with me.
Chris


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## robdamanii (Sep 27, 2005)

My question with the Garmin edge models is this:

Once you ride a route, can you re-ride it and will it track your progress on said route (if you've strayed off of it for example) and does it have a "return to start point" feature?


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## revrnd (Aug 13, 2004)

This is the 2nd season I've used my Legend. You can manually enter waypoints from a map & it has "trackback" feature. when you want to return to your starting point, you reverse your "track" & follow it back. 

I have lost reception w/ it when riding in a ravine & heavy hardwood forest. Other than that, no complaints.


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## dan0 (Oct 12, 2005)

barber said:


> The Garmin is okay, but it is WAAAAAAY overpriced for something with no color. I could get a nice automobile GPS unit for that price which would have more features that the Garmin doesn't have, such as 3-d mapping, color screen, voice turn-by-turn directions, higher resolution, etc etc.


but could you put it on your bike?
BTW the gpsmap 60csx IS color, IS 3d, is high resoloution, but you are right about 1 thing it doesnt have voice turn by turn

also for that price you cant get a car unit with all those features


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## dan0 (Oct 12, 2005)

robdamanii said:


> My question with the Garmin edge models is this:
> 
> Once you ride a route, can you re-ride it and will it track your progress on said route (if you've strayed off of it for example) and does it have a "return to start point" feature?


it will track your progress, in fact you can set it up to compete against yourself or an imaginary rider, but its really a training computer not a mapping gps . when you get home you can upload your trails to a pc and print a map but no map on gps unit just trails


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## mecrens (Aug 17, 2005)

I rode a few times with my garmin and was not impressed with the results. The distance traveled was way off. I think the "sampling" for identifying location does not produce a true route. I would also lose signal periodically because of tree cover/


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## dan0 (Oct 12, 2005)

mecrens said:


> I rode a few times with my garmin and was not impressed with the results. The distance traveled was way off. I think the "sampling" for identifying location does not produce a true route. I would also lose signal periodically because of tree cover/


I nnoticed that with the etrex series. The new gpsmap and 205/305 series have the sirf antenae which works way better, I had the 305 and the distance and speed were spot on with my cateye computer, and they get alot better reception also


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## Whiffle (May 2, 2006)

This is something I just made w/ USAPhotomaps and data from a ride i did in March w/ the gps strapped to the side of my pack in its case, the blue line is my track 

https://www.resnet.trinity.edu/avaselaa/test.jpg

I can post some how-to instructions later if anybody's interested.

The same thing can be done w/ aerial photos as well, although most aerial photos are about 20 years old...


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## @dam (Jan 28, 2004)

Has anyone here found their GPS systems to be genuinly useful, or are they mostly just toys used to create cool maps and stuff?


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## robdamanii (Sep 27, 2005)

dan0 said:


> it will track your progress, in fact you can set it up to compete against yourself or an imaginary rider, but its really a training computer not a mapping gps . when you get home you can upload your trails to a pc and print a map but no map on gps unit just trails


I know it's not a mapping gps type thing, but my real idea is that I can ride a trail, then set it up to compete against myself. I'm questioning if it will tell me or show me that I'm off the trail that has been GPSed prior?


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## Golddr2000 (May 4, 2004)

I have the 305 and it will show you where to go. However they are only arrows going over a dotted line diagram of a previous course you recorded.Which is good enough for racing your self. You can set it up to race against time,distance,etc. I love mine.

Pat


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## MC9.5 (Nov 11, 2004)

Rhino 120 w/Handlebar Mount.
The Handlebar Mount is a must!


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## barber (Apr 28, 2006)

dan0 said:


> but could you put it on your bike?
> BTW the gpsmap 60csx IS color, IS 3d, is high resoloution, but you are right about 1 thing it doesnt have voice turn by turn
> 
> also for that price you cant get a car unit with all those features


Well, the price that my LBS is charging for the new Garmin you can go to BestBuy and get a freaking car GPS unit. Of course, it won't fit on the bike like you say.


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## dan0 (Oct 12, 2005)

@dam said:


> Has anyone here found their GPS systems to be genuinly useful, or are they mostly just toys used to create cool maps and stuff?


thay are usefull if you ride in unknnown areas otherwise a cool toy


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## Mr_Whiskerz (Mar 25, 2006)

I have a plain Garmin eTrex, and I have a good bit of trouble keeping signal in the woods. It also seems to take a good bit of time to acquire a signal. Part of the problem may have been that I was using the neckstrap. I will have to test lashing it to the Camelbak...


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## Harold (Dec 23, 2003)

I've been using a Rino 120 while biking (and hiking) for nearly 3 years now. I put it in the mesh pocket on my Camelbak b/c it gets a better signal there than it does on the handlebars or on my shoulder strap. With my body between the receiver and the satellites, it DOES make a difference in reception.

Eventually, when the necessary funds aren't already claimed by higher priority things, I'll upgrade to a map 60CSX that has color screen, more memory, and improved sensitivity. Until then, the Rino 120 works well enough.

If you think you're going to use a standard GPS (not one of the Edge models that uses a wheel sensor) to compare distance to a regular bike computer, you're using it incorrectly. The GPS DOES NOT take elevation into account when calculating distance. It only uses straight horizontal distance. Elevation changes will make the distance the GPS reads different from what your bike computer reads. The Edge models with the wheel censor fix this problem by combining the bike computer with the GPS so that distance readouts are given based on wheel sensor input, not from satellite signals.

As for making a map, as long as the GPS receiver has pc connectivity and will save a track or course, then you can make a map of your trail on the computer. There are TONS of programs on the market that will do this for you. Some are free, some are not. In my experience, you get what you pay for.

$100 for the Garmin program that lets you load topos onto your GPS is fairly reasonable, actually. You can save some cash by purchasing a package deal, but it takes a TON of work to digitize paper maps (which is what that software is). Granted, I wish they'd issue a newer version that has not only functionality improvements but data revisions (those maps are pretty outdated, really). The NG Topo program costs you $100 for a whole state (or a group of small states, or part of a big state), but that software rules. One of these days, I will get the version that integrates into ArcGIS, but that package costs roughly $500, IIRC.

A car GPS is pretty much crap for anything except a car. Just like the Edge is pretty much crap for anything except biking. They both have very specific functions and it's stupid to think that interchanging them would be an effective solution to the problem. Some sales lackey at Sportsman's Warehouse tried selling me a car GPS while I was drooling over the 60CSX...retard. Different tools for different problems. I wouldn't use a screwdriver to hammer a nail.

My current preference is to have a bike computer for bike computer functions and a mapping GPS for making maps. One of these days, I imagine Garmin will make an Edge computer with more mapping functions to satisfy map geeks, but I really have no need for any of the training computer functions that the Edge offers. I still only ever buy the least expensive bike computers, as all I want are speed and distance functions (and mostly just the distance functions). 

I like to use my GPS to keep track of where I've ridden in confusing trail systems (the nearest trails to me have some confusing parts), to mark intersections or sections of singletrack off of the roads, and to map preferred routes or entire trail systems. On simple trail systems (basic loops or out-and-backs), I don't even carry the GPS unless there's something new that needs mapping. More often than not, I get a pretty good signal. The Rino has a quad helix antenna, so it's better than the basic eTrex models, but no SiRF chip, so it's not as good as the 60CX/CSX. It's pretty similar to the standard 60 C/CS models in reception quality. I occasionally lose a signal for a moment, but it's never for long. 

Do yourselves a favor, if you like using a GPS on rides, find the Trimble Office program. There's a planning utility in there that will give you signal quality for any particular day and location. More often than not, signals lost due to "thick canopy" are actually due to poor satellite geometry or coverage, which is something you can avoid entirely if you plan your ride around it. Signal loss due to topography is more problematic, though, because there's not much you can do about it. The problem is exacerbated by thick canopy and poor geometry or coverage, but if you're on the northern slope of a mountain or big hill, reception on your GPS will suffer. Cheaper models will lose the signal entirely, while more expensive models will just have larger margins for error.


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## roadiegonebad (Jan 31, 2004)

Mr_Whiskerz said:


> I have a plain Garmin eTrex, and I have a good bit of trouble keeping signal in the woods. It also seems to take a good bit of time to acquire a signal. Part of the problem may have been that I was using the neckstrap. I will have to test lashing it to the Camelbak...


Orientation of the unit definitely makes a difference with these. In thick cover the best reception is likely with bar mount, definitely not on neck, in pocket or camelbak, etc. Yeah, you'll look like a tech-geek but that's the price you pay.


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## robdamanii (Sep 27, 2005)

Golddr2000 said:


> I have the 305 and it will show you where to go. However they are only arrows going over a dotted line diagram of a previous course you recorded.Which is good enough for racing your self. You can set it up to race against time,distance,etc. I love mine.
> 
> Pat


So it's just a dotted trail? What happens if you stray off that trail that you're racing on? Does it show you in relation to the trail you're supposed to be on?


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## Nathan Cloud (Jul 18, 2005)

hugh088 said:


> As one RI guy to another I can give you some info on how that unit works the great MTB'ing state of RI. In short pretty good. In the summer you will likely lose some signal while riding under heavy cover. I usually make a track when I ride and will get straight lines on the track for maybe 10% of the ride. This will usually not effect the track much when you plot it. I can always get a signal when I stop and check where I am or to mark a way point. Even in heavy cover, stopping allows enough weak signals to be seen by the unit to decide that it can give you a position and an error circle. As for carrying it, I have a Garmin soft case that has a plastic window in it. I attached this to the shoulder of my camelback so that it points up while riding. If you ever get to Big River be sure to carry your GPS, it's easy to get lost there. Use the track feature and plot it to USAPhotoMaps. Plot it on the maps not the photos for ease of use. Email me at [email protected] and I'll send you a copy of some plots I have with me.
> Chris


Speaking of Big River, one of the guys on mt site uploaded this track:
Info: http://www.crankfire.com/trails/data.php?dataid=136
Map: http://www.crankfire.com/map/index.php?tid=82&t=136&w=0

70+ miles of trails mapped. Thought it might be of use?

He also upped a 115+ mile track of trails in Arcadia :eekster:



swampmonster said:


> GPS... I have a few my, old Stand by is a Garmin 12xl, I also have a Garmin V, 76cs+, Trimble GeoExplorer, and my newest one on order is the Garmin M5 PDA/GPS in one, and it runs on Windows CE...so far teh 76 is my fav, it can do it all but the old 12xl just will not die. The problem is finding good software that will let you do what you are wanting to do. I am still working to find one I like


Topofusion? It my favorite  and was written by mtn bikers.


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## drgonzo (Apr 13, 2006)

The one thing that's kept me from buying a reciever so far is the fear that it won't work in the woods. Why buy something that you know won't work? I'd love to get the MAP60, but I don't have 300 bucks lieing around to drop on a gps. I'm more intrsted in the maps that the unit generates than using it for real time navigation, so if it's going to give me inaccurate maps I don't see it being worth the investment.


NateHawk said:


> The GPS DOES NOT take elevation into account when calculating distance. It only uses straight horizontal distance. Elevation changes will make the distance the GPS reads different from what your bike computer reads.


I know garmin has some other recievers on the same line as the Legend, some of which include an altimiter and barometer. The baro isn't as applicable, but do you think the ones with the altimiter fix the problem that you mentioned?


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## revrnd (Aug 13, 2004)

mecrens said:


> I rode a few times with my garmin and was not impressed with the results. The distance traveled was way off. I think the "sampling" for identifying location does not produce a true route. I would also lose signal periodically because of tree cover/


I checked a known distance w/ my Etrex Legend today & the distance was dead on @ 4 miles.


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## Harold (Dec 23, 2003)

drgonzo said:


> The one thing that's kept me from buying a reciever so far is the fear that it won't work in the woods. Why buy something that you know won't work? I'd love to get the MAP60, but I don't have 300 bucks lieing around to drop on a gps. I'm more intrsted in the maps that the unit generates than using it for real time navigation, so if it's going to give me inaccurate maps I don't see it being worth the investment.
> I know garmin has some other recievers on the same line as the Legend, some of which include an altimiter and barometer. The baro isn't as applicable, but do you think the ones with the altimiter fix the problem that you mentioned?


No. They don't. The barometric altimeter is a separate sensor than the GPS receiver. The receiver just isn't wired to make those calculations for the trip computer function. The best you're going to get is to load your track into a program like National Geographic Topo that has elevation data embedded into the map data and will run the trig calculations to determine the ACTUAL distance rather than just horizontal distance OR just get a computer with a wheel sensor.

Even then, it won't be the most accurate method due to a large number of factors including map resolution, error in the track points, and error in the elevation data embedded in the map software. Determining elevation has never been and probably never will be an exact science in our lifetimes.

You really don't have to worry so much about a particular receiver not working in the woods. It will work, most of the time. You just have to be aware of the factors that limit reception and work around them. As long as you aren't relying on your GPS for your life, it's no big deal if you lose the signal for a couple minutes. You can spend many thousands of dollars on GPS equipment and STILL not be satisfied with the outcome.


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## KONA_in_SB (May 20, 2004)

I use a Garmin Foretrex 201. I can fully interface with it on my PC useing a free program clled 
GPS Utlity (GPSU). I can make maps like the following by download topo data (not topo maps) for fre from the USGS website. I uses Python to manipluate the data files from GPSU and Matlab to plot both the tracks and topo data up.
The great ting is that all this is free. The bad thing is that you need to know how to program in Matlab. Below is a link to one of the first maps I made. I have been slowly improving them sinse but its really aside prject so work is slow. 
http://www.opl.ucsb.edu/black/pics/AB_loop020406/020406ride.tif


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## drgonzo (Apr 13, 2006)

NateHawk said:


> You really don't have to worry so much about a particular receiver not working in the woods. It will work, most of the time. You just have to be aware of the factors that limit reception and work around them. As long as you aren't relying on your GPS for your life, it's no big deal if you lose the signal for a couple minutes. You can spend many thousands of dollars on GPS equipment and STILL not be satisfied with the outcome.


Well, that makes me feel a bit better about not being able to afford the more expensive stuff. I don't think I want to mount the reciever to my handlebars, if I do use it it will be in a situation where I stop to figure out where I'm going, and have the ability to wait a minute if nesscessary for the unit to acquire signals. Like I said before, what I really want is to be able to make maps with this, I'm unfamiliar with the local terrain and I want to be able to track what I've done, so I can see what trails go where and hopefully discover new ones.

I'm still up in the air as to whether I want to get one yet or not, but if I found a good deal on the Legend I think I'd bite on that. Has anybody used the Magellin eXplorist line of recievers? They seem priced a little lower with better features, but as far as I'm concerned you get what you pay for.


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## dan0 (Oct 12, 2005)

drgonzo said:


> The one thing that's kept me from buying a reciever so far is the fear that it won't work in the woods. Why buy something that you know won't work? I'd love to get the MAP60, but I don't have 300 bucks lieing around to drop on a gps. I'm more intrsted in the maps that the unit generates than using it for real time navigation, so if it's going to give me inaccurate maps I don't see it being worth the investment.
> I know garmin has some other recievers on the same line as the Legend, some of which include an altimiter and barometer. The baro isn't as applicable, but do you think the ones with the altimiter fix the problem that you mentioned?


if you dont care about the real time navigation then the edge will do it for you, when i had mine I purchased the topo maps for the east coast and it uploaded my trails onto the map, then you can edit or print. If you don't care about the hr or cadence and the gps altimiter is fine get the 205.and save $100, if you want the training stuff and a barometric altimeter get the 305. the topo maps are pretty good, I know there are some out there that are better but they dont upload to the gps only garmin maps do. the best thing about the edge series is the size and reception, they are flip phone sized and the sirf antanae comes in faster, better and more accurate.


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## dan0 (Oct 12, 2005)

NateHawk said:


> No. They don't. The barometric altimeter is a separate sensor than the GPS receiver. The receiver just isn't wired to make those calculations for the trip computer function. The best you're going to get is to load your track into a program like National Geographic Topo that has elevation data embedded into the map data and will run the trig calculations to determine the ACTUAL distance rather than just horizontal distance OR just get a computer with a wheel sensor.
> 
> Even then, it won't be the most accurate method due to a large number of factors including map resolution, error in the track points, and error in the elevation data embedded in the map software. Determining elevation has never been and probably never will be an exact science in our lifetimes.
> 
> You really don't have to worry so much about a particular receiver not working in the woods. It will work, most of the time. You just have to be aware of the factors that limit reception and work around them. As long as you aren't relying on your GPS for your life, it's no big deal if you lose the signal for a couple minutes. You can spend many thousands of dollars on GPS equipment and STILL not be satisfied with the outcome.


FYI
the garmin 205 edge uses the gps data to calculate the altimeter, the 305 uses a seperate barometric sensor, also the sirf antanae once it logs on to 4 satalittes gives you 3d mapping


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## Jayem (Jul 16, 2005)

drgonzo said:


> The baro isn't as applicable, but do you think the ones with the altimiter fix the problem that you mentioned?


Baro-aiding allows the GPS unit to work with one less satallite, so if you are concerned about reception, this could be a big aid, although you have to know and input the altimeter setting every time you are going to use it for this feature to work. This feature will allow the GPS unit to know how far it is above the standard datum plane (altitude above sea level). Not a problem for me, as I'm a pilot, and I have weather sources that tell me the altimeter setting before I fly every time, so I can set my GPS units and the other instruments that require the altimeter settings. On the other hand, if you don't have a way to get the altimeter setting, it's fairly useless. Personally I'd go for it due to the fact that it would allow for better reception (less satallites required).

The baro-aiding can also be thought of as a "starting point", although if it's input incorrectly the GPS unit will need more satallites and then self correct if possible. The baro aiding is not for altitude calculation directly, but it works more of a "start point" for the GPS.


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## Speedub.Nate (Dec 31, 2003)

Jayem said:


> Baro-aiding allows the GPS unit to work with one less satallite, so if you are concerned about reception, this could be a big aid, although you have to know and input the altimeter setting every time you are going to use it


I have a friend that, one night a dozen years ago, kinda drunk at a bar, approached a hottie singer from a local band and bragged, "_You're really good, and I should know... I play the guitar, too!_" (He wasn't, and still isn't, a very good guitarist.) We kid him to this day.

Without busting your balls too hard, what I'm saying is, "I'm a pilot so I should know" is getting a bit old and you're spewing some bogus info here...

But hear me out! I just want to make a couple of points.

First off, the Garmin units with built in barometric pressure sensors auto-calibrate to GPS altitude -- no calibration necessary on the user's part.

A GPS receiver's ability to calculate elevation has nothing to do with "one more/less satellite". The receivers simply doesn't calculate vertical relations as accurately as horizontal due to the geometry of the satellites (generally) overhead. More satellites will always be better than less satellites, but there is no magic cut-off where altitude calcs suddenly stop working.

Fixed GPS-based elevation calculations (pre-ride, parking lot) can be relatively accurate. GPS elevations while mobile can be spiked with errors. GPS paired with baro is a very pretty thing, indeed.

Setting an altimeter to local airfield elevation is no different than setting an altimeter to a local trailhead parking lot elevation. A barometric altimeter setting can be pretty useless to most cyclists since the setting is corrected to local field elevation, and most cyclist-type altimeters won't have a place to enter this anyway. But anybody (not just pilots) can log on to any number of online resources, or in many cases call a local telephone number, to retrieve a current barometric altimeter setting (should they desire).

FWIW, I'm a pilot too, but it has absolutely no bearing on this conversation 

Honestly, no hard feelings, Jayem, I'm just trying to clarify some inaccuracies.


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## Speedub.Nate (Dec 31, 2003)

Good news on the Garmin Edge front!

Around Interbike '06, keep your eyes open for a v.2 Edge with routes. This will give the user the ability to upload a network of trails onto the device and go explore, without being stuck on a single pre-defined route.


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## Jayem (Jul 16, 2005)

Speedub.Nate said:


> First off, the Garmin units with built in barometric pressure sensors auto-calibrate to GPS altitude -- no calibration necessary on the user's part..


That doesn't really make sense, if the GPS is not accurate for altitude, how can it calibrate? The pressure varies, so as high or low pressure systems move through, the pressure will change, and the GPS won't know the difference unless you actually input a number into it.


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## Speedub.Nate (Dec 31, 2003)

Jayem said:


> That doesn't really make sense, if the GPS is not accurate for altitude, how can it calibrate? The pressure varies, so as high or low pressure systems move through, the pressure will change, and the GPS won't know the difference unless you actually input a number into it.


Honestly, that's not the case. I don't know the algorithm Garmin uses for calibration, but I doubt seriously the barometric side is calibrated in any enroute mode.

You're right, entering a precisely known elevation off of a countour map or surveyed point would be most accurate, but a static GPS-obtained elevation (while the unit sits for a couple of minutes) is generally "close enough" for general use.

And you are correct that if the barometric pressure swings wildly during the ride, the unit will display an incorrect elevation just like any other barometric altimeter -- until it re-self-calibrates at some point (presumably when the unit has come to rest during a rest break).

The eTrex units do allow the user to manually input a barometic pressure setting, but I don't believe this is true of the Edge units.


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## SwissBuster (Jan 19, 2004)

*MY GPS experience*



drgonzo said:


> A lot of people I talk to about this complain about how these devices don't work good in the woods under a canopy, pretty much where I do most of my riding. I would like to be able to just drop it in my camelbak so I can look at it when I stop cause I realize I'm lost, but I also hear that you can't put these in bags? How about if there's only one layer of fabric between the gps and the sky (i.e. an outside pocket)?


I have used mine on my wrist skiing, when the GPS is under the arm of my ski jacket. It works 100% - I've never experience a lost signal skiing. I sometimes loose a signal under dense canopies or in a narrow valley. I hear the new models have a better reception (eg Forerunner 205).

Reading all the posts there seems to be some confusion about 'mapping'. Some models (eg 60S) have a true mapping feature where you can use Garmins proprietary (and expensive) maps (topo or other) to see a moving map of your travels on the GPS unit. As the screens tend to be small, advice I have heard is that they cannot replace a map.

Most Garmin models will allow you to download recorded data onto a PC for viewing in mapping software (eg GoogleEarth or OziExplorer). Here's one of my route to work (barely visible thin red line is my commute on the shores of Lake Geneva).








If by 'mapping' you want this ability to make maps of your rides, these models allow this.

My Foretrex, which is typical of most 'non-mapping' units, also has a screen which displays a breadcrumb trail of your route. This also shows any waypoints you've entered (or downloaded) so can form a map of sorts. You can also program it to direct you to a waypoint, to backtrack along your route, or you can program a route to lead you along a collection of waypoints (never used this feature - I suspect it works by leading you to the waypoints you program in the right order).



mecrens said:


> I rode a few times with my garmin and was not impressed with the results. The distance traveled was way off. I think the "sampling" for identifying location does not produce a true route. I would also lose signal periodically because of tree cover/


When I get home I always download the data, check the route in OziExplorer and correct it if necessary. I've found that there are sometimes a couple of errors (depending on terrain), and the garmin usually underreports the total distance. Of course, once its corrected the measurement is perfect - better than your typical bike computer. Like NateHawk says, the GPS reading is a 2D measurement, so you need to correct for height gain. If you use OziExplorer, there is a neat piece of freeware called TrackAn which gives you a cool summary of your routes. In practise, the difference between 2D and 3D is not big unless you're skiing or otherwise making serious altitude gains. NateHawk's posts offer, IMHO, excellent advice.



robdamanii said:


> I know it's not a mapping gps type thing, but my real idea is that I can ride a trail, then set it up to compete against myself. I'm questioning if it will tell me or show me that I'm off the trail that has been GPSed prior?


The Forerunner models have a 'training parnter' feature which allow you to do this. It will tell you if you are ahead or behind your previous run, but I don't know if it tells you that you're off course.



Nathan Cloud said:


> I would not really recommend mounting the gps to your handlebars - its distracting, not necesarily secure, and puts your gps in a prime place for damage. Not to mention all the vibration could do some damage to the unit (but thats more or less hear-say).


To each his own. I use it on the bars as a replacement bike computer. The Foretrex is attached with a bike holder and the wrist strap wraps around the bar, so its as secure as on the wrist. Vibration (if that is a factor) is similar to on the wrist. I personally don't like wearing it on my wrist riding because my wrist is slightly bent so it digs into the back on my hand.



@dam said:


> Has anyone here found their GPS systems to be genuinly useful, or are they mostly just toys used to create cool maps and stuff?


Depends how you define useful. For me it has replaced my bike computer, and I can use it skiing and running too. I feel naked leaving home without it!



drgonzo said:


> The one thing that's kept me from buying a reciever so far is the fear that it won't work in the woods. I'd love to get the MAP60, but I don't have 300 bucks lying around to drop on a gps. I'm more intersted in the maps that the unit generates than using it for real time navigation, so if it's going to give me inaccurate maps I don't see it being worth the investment.
> I know garmin has some other recievers on the same line as the Legend, some of which include an altimiter and barometer. The baro isn't as applicable, but do you think the ones with the altimiter fix the problem that you mentioned?


I went throught the same headache before I bought. My advice is: you don't need the barometric altimeter as your GPS will give an altitude readout which, on mine, I have always found to be exceptionally accurate (at fixed points - it can screw up if you are downhilling fast and 'catches up' when you slow down). It sounds like you don't need true mapping, so go for a cheap device to see if you like the technology. You won't look back!


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## lushmd (Apr 9, 2004)

Speedub.Nate said:


> Good news on the Garmin Edge front!
> 
> Around Interbike '06, keep your eyes open for a v.2 Edge with routes. This will give the user the ability to upload a network of trails onto the device and go explore, without being stuck on a single pre-defined route.


Hey Nate, have you heard anything new regarding the updated Edge (will it offer a proper map view?...expandable memory?)? I haven't been able to find anything about it online. Thanks.


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## Ultra Magnus (Jan 13, 2004)

I've ridden with the Forerunner for quite a while, as I posted a while ago, and I just recently got the edge 305+hr for my birthday. With the forerunner, the eleveation profile of my commute to work (with graph smoothing turned off) was very jagged, and if I compared one ride to the next and overlayed two elevation profiles, there were massive discrepencies.

With the edge that has the baro altimeter, when I compare the same route over another, the elevation traces are almost identical. there's a few feet variance, but it is wicked more consistent (and I'd also assume accurate) over the forerunner. Now I don't know jack didly about the ins and outs of how these things work, just a basic assumtion that they use triangulation to figure out where you are. And in my simple understanding, the angles to figure elevation are (I assume) very narrow so a slight miss in an angle could mean a huge variance in actual elevation. I'd think the baro would do like it's advertised and give one more input ot furthur improve the accuracy of the device. I most also say, that some mornings I have noticed incorrect elevation differences betwen my work and my house. One day it told me my elevation at home was 2950 and on another it said 2850, I figure this to be the barometric pressure changes Jayem was talking about. By the time I got to work, it had the (I assume) correct altitude of 3050'.

I'd also imagine with the Cadence/wheel sensor accerssory you'd even futher improve your distance calculations. BTW, the wheel sensor has an "auto calibrate" funciton, or you can manually enter your wheel circumference.

Also, the courses function of the edge 305 is wicked bad ass. I love that thing. I've yet to go off road with it (waitng on a warranty frame for my XC bike) and have only been road riding, I have not yet gone off "course" so I don't know what it would do. But, being able to race against yourself is a lot of fun and good motivation to work harder. My edge also gets far better reception than my forerunner ever did. My edge can actually get reception inside of my house.

BM


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## tls36 (Dec 10, 2005)

*Garmin Legend Cx*

Just ordered the Garmin, a bit bigger and no virtual competitor but should help keep me from getting lost. I will let you know what I think. Was considering the forerunner.


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## Nathan Cloud (Jul 18, 2005)

> A GPS receiver's ability to calculate elevation has nothing to do with "one more/less satellite".


From my understanding, you need 3 satellites to get a lat/lon, and a 4th for altitude. Beyond 3 or 4 it more or less helps if you lose reception of one of the satellites being tracked.

However, seeing that elevation is a semi-hot topic in this thread - I just want to throw in that the Topofusion software can add elevations to gps tracks . So if you don't entirely care what your elevation is while riding but love to look at the profiles after - everything is going to be mostly just fine!

Just my 2 cents.


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## revrnd (Aug 13, 2004)

tls36 said:


> Just ordered the Garmin, a bit bigger and no virtual competitor but should help keep me from getting lost. I will let you know what I think. Was considering the forerunner.


I just got a Legend CX on the spur of the moment. No loss of signal in the woods :thumbsup: .

The topoCanada software was 140 canadian for ALL of Canada.


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## dan0 (Oct 12, 2005)

Nathan Cloud said:


> From my understanding, you need 3 satellites to get a lat/lon, and a 4th for altitude. Beyond 3 or 4 it more or less helps if you lose reception of one of the satellites being tracked.
> 
> However, seeing that elevation is a semi-hot topic in this thread - I just want to throw in that the Topofusion software can add elevations to gps tracks . So if you don't entirely care what your elevation is while riding but love to look at the profiles after - everything is going to be mostly just fine!
> 
> Just my 2 cents.


the prob with elevation readings is the barometric reading will vary depending on weather and the gps reading is + /- the accuracy of the gps
they are close though


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## WarPigs (Dec 21, 2005)

NateHawk said:


> I've been using a Rino 120 while biking (and hiking) for nearly 3 years now. I put it in the mesh pocket on my Camelbak b/c it gets a better signal there than it does on the handlebars or on my shoulder strap. With my body between the receiver and the satellites, it DOES make a difference in reception.
> 
> Eventually, when the necessary funds aren't already claimed by higher priority things, I'll upgrade to a map 60CSX that has color screen, more memory, and improved sensitivity. Until then, the Rino 120 works well enough.
> 
> ...


Nate, have you used the Garmin GPS 12XL before? How would you rate it against the newer etrex series? in terms of getting a fixed signal, how much slower is the 12XL?

I've only used the 12XL, and I get frustrated sometimes when trying to get a fix.


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