Help! (GPS guidance)

[FoShizzle]

I want a GPS.

I only care about cumulative elevation gain, mileage, and time. But i want one that works and has a good antenna and I am thoroughly confused when I try to read up on them. I dont want an altimeter bike computer cause I hate the magnets on spokes cause with a fully rigid it is far from reliable....as many revolutions per ride are missed.

Any words of wisdom on which unit(s) may be optimal?

Cheers

 

[erider]

Shizzle, I use a Garmin Legend C with a color screen that tracks pretty well. Mostly just has my ride routes in the Santa Monica Mtns. You can buy a handlebar mount and mapping software for additional $$. Gives you speed, max speed, time, distance and elevation. Uses 2 AA batteries and is light enough to hold trail running. The new one is an eTrex Legend Cx that uses a new type of chip to pick up the satellite signal much faster. The Legend C is much cheaper now whereas the Legend Cx is around $250. Check pricegrabber.com and it will list the cheapest site. Can't go wrong with the Legend C since it pretty much has everything you want from a ride. You can also upload the data on the Garmin site to map the elevation data I see posted on mtb sites as well. I'm considering getting a forerunner 205 since it has a virtual lap times. It might be nice to have for training loops and definitely nice for running.

 

[CruIsRad!]

I got my Magellan SporTrak for $149, then I got a handlebar mount. I swear by it. I've had it for 4 years. Simple 2-color readout, and still has more functions than I could ever hope to use. The antenna technology is the same in almost all hand-held GPS units, I wouldn't worry about that too much. When it comes down to it, all GPS units will suffer in heavily wooded areas or deep canyons with high walls. I had a GPS on my old Montero also for 4x4 trips, connected to my laptop with trail maps. Fun stuff!

 

[dstepper]

I have used, both bike altimeter/computer and a GPS. There usually is a significant difference between the two...I thought the bike altimeter was more accurate recording elevation gains.

I have never used a GPS with a built in altimeter I have a feeling that would be the most accurate and give you elevation gain field results. On my old Garmin Legend I don't get elevation readings until I get home and sync it to a mapping program.

 

[dukethenuke]

I have the edge 305, and it's awesome. Built just for bike riding and you can add a heart monitor to it and a candance. The gps holds a signal really good and you can race yourself based on previous rides.

 

[FoShizzle]

thanks guys.

duke.....how does the altimeter work? does it work well to capture the cumulative elevation gain from your experience?

 

[Krunk]

I have the edge 305, and it's awesome. Built just for bike riding and you can add a heart monitor to it and a candance. The gps holds a signal really good and you can race yourself based on previous rides.

does the edge305 have waypoints?

 

[Andrew]

thanks guys.

duke.....how does the altimeter work? does it work well to capture the cumulative elevation gain from your experience?

I have an old Garmin Etrex Summit on my bike, which has an altimeter (barometer) and electronic compass. In order to show elevation changes accurately, you need a model that inludes a barometer; some GPS units will provide elevation data based on the GPS signal, which is not accurate enough for what you want. Assuming you get one that has a barometer, you will easilly be able to see 100 foot rises or falls no problem (I'm not sure of the how small a bump it will detect, but it is very good).

The absolute elevation data isn't too good unless you calibrate it at a location of known elevation. However, generally you are only interested in changes anyway so I don't bother with the calibration.

 

[FoShizzle]

thanks Andrew.....

so if i follow, some GPS units ALSO have an barometer whereas others capture elevation gain based on only the signal?

so is the keyword i am looking for when searching the various models barometer?

sorry for the dumb questions but i am confused when i look at all the models.

 

[Andrew]

thanks Andrew.....

so if i follow, some GPS units ALSO have an barometer whereas others capture elevation gain based on only the signal?

so is the keyword i am looking for when searching the various models barometer?

sorry for the dumb questions but i am confused when i look at all the models.

I am pretty sure that if it says it has an altimeter, that means it has a barometer / what you need. For example, http://www.garmin.com/products/etrexsummit/ is the one I have. You may be considering other manufacturers, but Garmin has a comparison page: http://www.garmin.com/outdoor/compare.jsp; you need one that has the "Built-In Barometric Altimeter".

 

[FoShizzle]

thanks so much Andrew!

 

[pshloss]

This is interesting... It turns out that I'm directly involved with an FAA system called WAAS which sends up a correction signal to improve GPS accuracy. http://www.garmin.com/aboutGPS/waas.html
The signal is broadcast from a special satellite in geosynchronous orbit. We routinely see 2 meter vertical accuracy for corrected positions. Almost all Garmin products are "WAAS-enabled". So I am surprised to see that they also sell units with barometric altimeters. I guess this allows you to turn off the WAAS feature to save power and to get good elevation readings when the correction signal is blocked by terrain or trees.

 

[FoShizzle]

This is interesting... It turns out that I'm directly involved with an FAA system called WAAS which sends up a correction signal to improve GPS accuracy. http://www.garmin.com/aboutGPS/waas.html
The signal is broadcast from a special satellite in geosynchronous orbit. We routinely see 2 meter vertical accuracy for corrected positions. Almost all Garmin products are "WAAS-enabled". So I am surprised to see that they also sell units with barometric altimeters. I guess this allows you to turn off the WAAS feature to save power and to get good elevation readings when the correction signal is blocked by terrain or trees.

From the little bit (very little bit) I understand, it is not a question of accuracy when it is working but rather the issue of not being able to get a signal in some areas in the first place in which case, the built in barometer would be preferable, no? Or perhaps I am cluess as usual

cheers

 

[pshloss]

You're basically right. Having a baro can make it so you need to be tracking fewer GPS satellites than you would otherwise. So you should get more reliable position (less outages).

 

[FoShizzle]

You're basically right. Having a baro can make it so you need to be tracking fewer GPS satellites than you would otherwise. So you should get more reliable position (less outages).

thanks for the clarification my friend

 

[royta]

I have the Garmin 60CS, which has the built in barometer and an electronic compass. I have both topo maps and street maps loaded onto it. I can enter an address in it, and it will tell me where to go to find the place. Very handy.

Even though I haven't gone OTB with my new bike, I still only keep the unit in the mesh of my Camelbak. In that location, it's good for tracking your rides, but not good at all for following an existing track log. My old GPS was a Garmin 12CX.