norsehabanero

the garmin vista has that you can get it at tiger direct for about 229.00 vista cx
gps is the only way to go
they are great

head_wind

If the physical package fits your bars OK I'd bet you will be happy with that.
For training I use a Garmin Forerunner 301 and it is OK for that. For travelling
it can't compare to my old Garmin III+ with it's good antenna. Too bad the III+
won't fit on a truck!

Quick discussion of GPS accuracy: with 3 satellites strong and in view 2 dimension
mapping works and a 4th is required for 3D which provides altitude. I believe
that every vendors software will use more satellites but don't actually know that.
Imagine 3 satellites in a straight line at the zenith which are very close together.
Compare that with three satellites near the horizon as far as possible from one
another (120 degrees apart). The time signals and location from the first three
in a row will be very close together while the three in a triangle will be seperated
more. Any computational errors from the three in a line will be a much larger
proportion of their time differences compared to the big triangle satellite configuration.
Therefore the three in a row will have noticably more error.

Since the GPS system uses LEO (low earth orbit, not geosynchronous ~23,000 miles
away) satellites their congiguration in the sky above you changes all the time, as
does the accuracy. Both of my Garmins have a GPS screen which shows the actual
satellite configuration above you and something which indicates the error magnitude.

A rule of thumb that I've heard is that the altitude error is about 3 times the lat/long
error. I take that on faith but don't really know how it withstands scrutiny.

BTW, I've heard of people who are happy using their GPSs with Google Earth instead
of buying maps. (There may be a $20 US/year charge for the software that integrates
Google Earth with your tracks. I can't remember but I'll bet that Google can.)

dekindy

My buddy hit a bump crossing a bridge and his GPS was knocked loose from the bracket and fell into the river never to be seen again. Pretty expensive gadget to be putting on a bike that could crash or otherwise lose it. Just food for thought. He sometimes loses signal and does not get accuracy that a computer would get.

CdCf

Actually, four satellites is the minimum number of satellites required to give an unambiguous position. With three, there are two possible locations. Of course, if one of the two positions is outside the altitude limit of a commercial GPS unit, or below the geoid surface, then the other position can be assumed correct.

But, even in the best possible conditions, the average positional error is on the order of 15-20 ft.

spinnaker

You are riding a $1000+ machine that you could easily crash too. It's all about risks. My GPS has gone flying off the bike a couple of times. Each time was due to the fact that I did not latch it properly. Now I am more careful.

But I agree, if you just want something to keep track of miles etc. then a computer is the way to go. The batteries will last forever. I have a computer and a GPS. I only use the GPS when I want to go and explore a new area.

I am also thinking of buying a Garmin Edge. Not so much to use it to keep track of fitness but I write software for the Garmin that is used by other programmers. I would like to add the Edge fitness protocols to my software.

Bekologist

this is not an endorsement of a product, but all the 305 series Garmin EDGE are GPS-enabled cycling computers with a temperature compensated barometric altimeter.The lower priced EDGE 205 doesn't have a barometric altimeter and relies on GPS for the altitude reading.

If you get the Edge WITH cadence you also get a wireless speed/cadence sensor. you can also get it with heart monitor functions, or both heart rate and cadence.

it does not let you look at nice maps on the screen although it does do waypoint nav as well as offer post ride downloads that let you extrapolate your rides on maps via your computer.

it is primarily a tool for training and etc, designed first and foremost as a cycling computer.

Magnum Man

Hello, I saw your pic of the GPS unit (looks good by the way) and was wondering if the mounting system you used could hold a small radio such as a Yaesu VX-6R. The radio is a small hand held (walkie talkie like) that I use during local emergencies. It is probably a little bigger than your GPS.

Anyway I'm looking for something to hold my radio while I ride.

spinnaker

Check out the Ram Mount. They have a wide variety of mounting systems.

socalrider

If you are really looking for a do everything gps, look at the new Garmin Dakota 20.. Full screen gps with touchscreen technology.. Just a little smaller than the Oregon series but bigger than the 705.. The Dakota 20 allow you to use the Garmin HR and Cadence-Speed Functions.. Spoke to a salesperson at REI and these things are selling fast.. Seems like most places are out of stock right now.

they sell for 349.000 msrp but can be found online for 280.00.. Just a note that there is lower model Garmin Dakota 10, this model does not allow you to use your cycling specific accessories..


Garmin site: https://buy.garmin.com/shop/shop.do?pID=30926

REVIEWS
https://www.gpsfix.net/gamin-dakota-2...t-impressions/
https://gpstracklog.com/2009/10/garmi...20-review.html

enine

Get the newer Garmin's with the H in the model (legend/vista), those have the more sensitive chipset and will work well between tall buildings or under bridges/tunnels/trees.
I use the neck lanyard wrapped around the handlebars as a safety, if mine would ever come unclipped it would just hang by the lanyard.
Another advantage of the GPS over a dedicated bicycle computer is taking it off the bicycle and on a walking/jogging/hiking trail. I also let mine log to a gpx file on the microsd card and then geotag pictures afterward.

njkayaker

This is likely incorrect. The Dakota 20 is $350. The Edge 705 (which does do the HR/Cadence/Speed stuff using ANT+) is $500.

Athens80

I see in the Garmin Dakota owner's manual (page 29) that the Dakota 20 can be paired with an optional Garmin heart rate monitor and an optional Garmin bike cadence sensor, and display the values on the map page, the compass page, and the trip computer. What does a cyclist get from a fitness Garmin -- a Forerunner or Edge -- that is not available on the Dakota for less money than the Edge 705? I don't see any reference in the Dakota manual to power meters, or to the training functions, for instance.

prathmann

I got a handheld Garmin eMap (now obsolete) eleven years ago in lieu of a cyclometer and would never go back (although I can see some sense in having both). Accuracy in general is very good and when comparing distances on club rides I find that my numbers are almost always somewhere in the middle of those recorded by folks with cyclometers. There are occasional glitches, especially in the urban canyons of city centers where the buildings hide much of the sky and also create reflected satellite signals, and also in dense redwood forests where the unit will lose satellite contact periodically. That can reduce the recorded mileage slightly, but it's very rare that the discrepancy is significant. OTOH, the max. speed reading can be thrown way off by a single false reading and I do sometimes get clearly spurious values for this.

But the benefits are numerous - being able to see at all times where you are on the map, what alternate routes will get you back if you're getting tired or running out of time, keeping records of where you went, how fast you were, etc. I also upload many of my rides and associated pictures to the everytrail.com site, such as this one from yesterday:
https://www.everytrail.com/view_trip.php?trip_id=429752
[the site looks at the time stamps on the GPS tracklog and compares to the times embedded in the picture files to determine where each photo was taken]

The GPS is especially handy while touring since the maps contain the locations of millions of businesses. Being able to find the location of the next grocery store, bike shop, library, or emergency motel has come in very handy at various times.

enine

I save all my gps logs too, uploaded to everytrail
https://go.bikeforums.net/?id=42X1295...er%3Dtrip_date

socalrider

This feature is available for the Dakota 20, the Oregon 400 series and 550 series.. I think the size of the oregon is why many people did not use it for cycling, but this new model is a little more compact in size, similar to the etrex hcx series in size but more useable screen size.. The screen is being touted in reviews as working better in direct sunlight versus the oregon series..I have seen a couple of reviews on MTB sites praising the new Dakota model..

You are right, why pay 500.00 for a 705 when you can get the dakota for less, even if you factor in buying optional maps, it is still less in price..

Dakota screen size: 1.43"W x 2.15"H
Edge 705 Screen Size: 1.37" x 1.71"
Oregon Series gps: 1.53"W x 2.55"H

njkayaker

Interesting.

I'd think that the device displaying the ANT+ data would have to know about what kind of data is being sent to it. For example, since there is no way of telling the speed transmitter what the wheel size is, the conversion of wheel rotation pulses has to be converted to speed at the display/head unit. To be able to display power, I'd guess the display/head unit would have to be preprogrammed to display power. This wouldn't be hard to do but it might be the thing, along with the training functions, that distinguishes the Dakota 20 from the more-expensive Edge 705.

The other thing that distinguishes the Edge 705 is a handle bar mount!

It's interesting that Garmin doesn't make this feature very apparent!

The $500 Edge 705 includes the $60 HR monitor and the $13 bike mount. The speed/cadence sensor is an extra $60.

It looks like the Dakota 20 can display non-computed data (basicallly, labeled counts/second), like HR and cadence.

(If I go with at GPS unit, I'd want one that would work for the car, hiking, kayaking, and bicycling. I wonder how well-suited for use in the car the Dakota would be.)

robapp

I use the velocomputer on my BlackBerry Storm 2. It doesn't have an immediate display of the path you are on, but it does output quite nicely into google maps and earth. It'll record distance, speed, acceleration, cadence, and position. More than decent for a 15 dollar app.

I work for them but I also use it so, I hope this isn't solicitation. Lemme know if it is and I'll delete the post.

Rob

TheLifeOfBryan

I've got a Garmin Forerunner 205, and have logged over 10,000 miles on it. I absolutely love it. But I'll soon be wearing a Forerunner 405cx, which will allow use of HRM and cadence sensor. For me, the key feature of a GPS is that in addition to being able see my speed and distance on my handlebars, when I get home I sync it with the computer and see a map, my speed at any given point, etc. and so forth. One big disadvantage of a GPS is that while they are a lot more accurate overall than one person in this thread seems to think, the speed displayed at any given moment is guaranteed to be a few seconds out of date. So if you're leading a paceline and need to maintain a dead level speed, a bike computer is essential. (I believe that the full cadence setup measures speed directly and shows that on the LCD, but I'm not 100% certain.)

DScott

My edge 705 is setup that way, and shows near-instant changes in speed. Cadence and elevation is always a few seconds behind.

njkayaker

That is correct. The Garmin speed/cadence detector uses a magnet on the wheel and another on the crank. It is as immediate as any other cyclometer. GPS-measured speed is quite accurate but it takes a while to get enough detail and the satellites have to be visible. I'd guess that GPS speed is more accurate at higher speeds (and longer distances). The GPS is probably not so good at measuring your speed doing slow donuts in the parking lot!

Good point. There has to be some reason for the added expense of the seemingly "reduntant" speed measurement!

socalrider

The Dakota uses the same handlebar mount as the Oregon/Colorado series.. Readily available at 10.00..

https://buy.garmin.com/shop/shop.do?pID=11411

BearSquirrel

A lot of cyclometers will do that as well.

A handheld GPS is NOT a good replacement for a cyclometer. It is not designed for vehicular use. Further, the altitude readings from a garden variety GPS wildly inaccurate. I guess someone reasoned knowing WHERE something is AND it's altitude are pretty critical to putting a missle on in it ;-)

In any case, the Garmin bike GPS units have barometric altimeters in addition to the GPS reading. You can also use a wireless speed sensor that will work regardless of cloud/leaf/building cover. You can also use wireless cadence and heart sensors with them. These are also things cyclists consider important.

njkayaker

[QUOTE=BearSquirrel;10106943]A lot of cyclometers will do that as well.

Note that a "handheld" GPS doesn't work any differently than the ones desgined for "vehicle" use (ie, ones designed for navigation use in cars. The problem with any of them is that they don't work very well at registering speeds at low speeds (this ends up not really being a problem for cars, because they are relatively fast).

Anyway, the real problem with GPS-only altitude measurements is that the GPS system was designed to locate position on 2-dimensional surface because that was really the only goal. (Adding precise altitude measurements would have made the system much more expensive.)

Actually, knowing the altitude is irrelevent for targetting missiles since it's generally good enough to be able to hit the ground that the target sits on!

To be able to determine altitude with more accuracy (to be any sort of use to people), the device needs more information than satellites can provide. GPS units use barometric pressure to provide that extra information.

The Garmin Dakota 20 (and some of the Oregon units) will display the data that cadence and HR monitors provide because the transmitters use ANT+ and these Garmin units are ANT+ recievers.

The Garmin Edge 705's one special feature is that it will display speed from a wheel-based transmittier by allowing the wheel size to be entered into the display unit. The other advantage of determining speed this way is that it doesn't need access to satellites and it is more accurate at low speeds.

BearSquirrel

No argument. But there is a big difference in how the different products are used. A handheld unit for field use has no navigation, so you wouldn't want to use it in your car. Likewise, a handheld GPS isn't optimized for bicycle use.


Agreed, they don't work well at low speed. But speed has nothing to do with it. The issue is that GPS measures speed by measuring the difference in position. It does so at specific time intervals. So if you move in anything other than a straight line, the GPS will under-report your speed and distance travelled.

No you're dealing with a 3-dimensional structure. Even if you use spherical coordinates, it's still a 3-dimensional system. I don't think the military would have forgotten that they have aircraft when they designed the system.

The ground sits at a specific altitude. I'm pretty sure if the missle is flying too high, it will miss the target. It's a 3 dimensional system and the only reason it would not matter is if you dropped it from a standstill immediately above the target.


Yes, cyclocomputers make better cyclocomputers.

njkayaker

It appears that the Dakota provide for turn-by-turn navigation. There's no real technical reason that a handheld can't have turn-by-turn navigation.

Speed is part of it because slow speeds (moving in a straight line) means your position doesn't change very much. And there is also margin of error with measuring position too. That means one would probaly get unreliable speed measurements going around in tight circles even if your speed is high.

No, GPS works worse for altitude and it's an inherent issue (maybe, related to the number of satellites). The military isn't forgetting: There are other ways of determining altitude (more accurately).

Of course, the cyclist is also going to be more sensitive to errors in altitude than he would be with errors in surface distance (a 500 ft climb is "significant" while a 500 surface distance traveled isn't).


https://www.gpsinformation.net/main/altitude.htm

I'd guess cruise-missles have some sort of radar to keep them off the ground when flying. And, if you are at the target, you can have the missle steer into the ground. That is, nothing needs to be missed.