Biking With A Gps

[+R4D4R]

I am going to purchase a GPSr sometim shortly and I really want to do some trail logging on my MTB. I was looking at the etrex Legend, but have also seen it is less than stellar on getting a signal under tree cover, which would cause a bit of a problem on a mountain bike. Basically, I want to hitch the GPSr onto the bike and log my route then download it to a Delorme topo map or similar to see where i went. Will this unit work out alright for mountain biking or should I pick something else out?

[+leatherman]

The track logs on an eTrex are very good. I think the size will be to your liking.

Unless your going to stand around stationary in heavy tree cover you should be fine with the eTrex. In fact the patch antenna will work better in canyons. It receives signals better with a vertical view of the sky.

 

The quad heli antennas do receive a little better under heavy tree cover. However they need a wider horizon, to receive sat signals.

 

Just be sure you can get a secure handle bar mount.

Edited March 10, 2004 by leatherman

[+Capitalpete]

luken, here is my take on it.

 

The legend works ok for most applications, but what you have to realize is that you give up some antenna performance for the small size of the unit. The eTrex series uses a patch antenna which does work well for its size. But the antenna is not as strong as the helical wound antennas used in the 76 series as well as other series of Garmins.

 

I have used them both together and found that the eTrex series does lose its track first in heavy brush. But, in all fairness it is much smaller than the gpsMAP76s. So you have to decide exactly what it is that you want, small size or somewhat better performance in brush.

 

If you choose one of the Garmins that can accept an external antenna then that leaves you with the option of using a seperate antenna that you can mount on your rear pannier rack. The reason that I say this is the 76 series works best in a vertical position, and I have found it very difficult to use on my mountain bike that way.

 

The 76 series will allow you to flat mount the unit where you can read it easily, and then set up the remote antenna on the pannier rack where it gets the best reception.

 

Of course, this is going to cost you way more money than simply using the legend, (which would be fine for likely 99% of all uses) but then the object of the game is ULTIMATE ACCURACY right? Afterall, money is no object when playing with such cool toys.

[+R4D4R]

nice, ive seen them kicking around on ebay for around $100 or so. Looks like ill be picking one up shortly. how well would it pick a signal up in a Camelbak? I would think it would be safer in my pack than on the handlebars, but if it cant get a signal, then i guess its a moot point

I have been thinking of fashioning some sort of bracket to attache to one of my h2o bottle cage mounts. i would assume it would be better off in the frame than sitting on top of the handlebars

[+R4D4R]

well lets put it this way, I will be doing most of my riding in new england under *moderate* tree cover. Basically under oak and maple trees that can let sunlight through to the ground and you can see out to the sky. its not 100% cover, about 75% total coverage of the sky between branches and leaves. basically you can look up and tell where the clouds are and still see planes flying around.

for anyone riding north of boston, its in Lynn Woods and the Fells for the most part...if that means anything to the rest of you.

 

can this thing accept an external wire antenna? that would probalby be the best of both worlds, hook it to the frame and wrap a wire antenna up out of the way

[+leatherman]

I'm pretty sure none of the eTrex's take an external antenna. If you want to use one you'll have to look into the GPS 3, the GPS 5, or the 76 series from Garmin.

 

You might find a good price for the GPS III+(3) on eBay.

[+Capitalpete]

luken,

 

Get a legend, get a bike mount, put it on the handlebars (good idea to keep the lanyard on it btw) and get out and enjoy it. Do not spend much time worrying about it, it is pretty darn tough. It will not recieve well in your camelback, and it will deprive you of the fun of using it while riding.

 

No, it will not accept an external antenna (except a rebroadcaster unit, very silly idea for a bike) and you will probably be fine with it. If after trying it for a while it does not live up to your expectations, sell it on eBay and cough up $$$ for a bigger unit that accepts an external antenna.

 

I like Garmin, but that being said, any of the big name units (Magellan, or Garmin) will work the same for you, except for the software differences. Remember whatever unit you get will be blocked out from some signals when your body is in the way of the satellite signals from that direction, the ONLY way around this is to get an external antenna and mount it ABOVE your body height. Pretty silly for most applications unless you are performing geodesic surveys from your bike while on the go.

 

Word of caution, don't get so wrapped up in looking at it that you forget to watch where you are going. Get it, use it, Enjoy it!

[+leatherman]

Sense the eTrex Legend has to be horizontal, here is a MoD for ya.

 

Get a Dremel. Trace out the Legend on the top of your bike helmet. Just slightly back from center. Dremel out a snug socket for your Legend, and secure it with some velcro tape. If you sink it in at least half way, I bet most people will not even see it.

Now it will always be at the highest point. It should be pretty safe there too.

 

:spell

Edited March 11, 2004 by leatherman

[Kafeajo]

I frequently bike with my GPS unit, which was an e-trex Legend until recently, when I lost it snowboarding off-piste and replaced it with a Vista.

 

I use the official bike mount, angled just enough for me to see the screen. As well as being great for tracking routes, you can upload a new route from the computer and follow that. I cycled a convoluted 65km of completely unfamiliar terrain without going wrong once, all thanks to the navigation skills of my Legend.

 

Without a signal amplifier, you will occasionally lose reception in trees. However, the vast majority of the time it will be fine. Though there are always tricky spots, like tree filled gullies, with most tree covered it is a matter of being lucky with the satellite constellation.

 

You should find this image interesting:

 

 

It is of a 45km, 400m elevation diff. bike circuit I frequently cycle around Zürich. The yellow is the track as recorded by the GPS, and the white underneath is the track it put together when it was saved (filling in the gaps). Where the yellow stops, I lost signal. This occurs a little in the bottom right corner, which is heavy forest. However, the majority of the right side of the route is also under similar tree cover. Basically, I was unlucky at that point. There is also a prominent loss of signal in the centre. This was one of those infamous tree filled gullies. Nonetheless, I was still unfortunate there – this image shows the track I recorded in that section (about 5km) on another day! Interestingly, the other part where I lost signal in the top left was just old and narrow European streets.

 

Signal loss really is no problem. I’m sure you wouldn’t regret purchasing a GPS for biking, and you’d probably find countless other uses for it as well. You might want to consider a GPS unit with an altimeter if you’re planning on doing elevation plots. The Legend wasn’t very good at this (it tends to do massive elevation updates every quarter hour or so, resulting in huge cliffs on the plot), and though I haven’t tried the Vista on my bike yet, it’s more than proved itself on the ski slopes.

[+R4D4R]

Thanks for the advice guys, it was really helpful. Im going ot keep my eyes peeled for one on ebay in the coming weeks. I have been watching a standard Meridian GPS and its only up to $50 right now.

I was thinking about also modding a water bottle cage to mount the reciever on

(see other post)

i seem to go over the bars more often than i should and dont want to take it out when i do. i guess thats a problem for my riding style rather than anything else

I dont really need it for navigating in the woods more than plotting where i have been, so I dont need to be looking at the thing *all* the time