Your recommendations for an elevation-measuring computer?

[Louis]

Back on the altitude thing, I’m thinking more and more seriously about getting an altitude-measuring computer (via atmospheric pressure, not a Garmin-type GPS). Anyone here have first- (or second) hand experience with any of the models out there? If so, what are your thoughts?

The options that come to mind right away are the Mavic Wintech Alti and one of the several Sigma models.

TIA

Louis

http://www.mavic.com/medias/products/zoom/520/107625.jpg

http://sigma-sport.de/en_media/produkte/bikecomputer/rox_wireless/rox_80/allgemein/visuals/img_1.gif

[Don49]

I use a Suunto Altimax wrist computer for elevation measuring on the road and mtn bikes. Very reliable, and the sample rate can be set for bicycling use. It measures accumulated ascent and descent on a ride and keeps a history by date. http://www.amazon.com/Suunto-Wrist-Top-Computer-Altimeter-Barometer/dp/B000051SER

Let's me use cheap Cateye computers on the bikes and still get elevation functions.

[AngryScientist]

as i alluded to in your other post, i just picked up a specialized branded computer the speedzone elite that has a temp compensated altimeter. great computer.

i use it when i dont feel like using the garmin. i did use them side by side a few times and the elevation numbers are pretty damned close.

i did a lot of research before i bought mine, and it was the best bang/buck @ $90. i highly recommend it.

[Louis]

I use a Suunto Altimax wrist computer for elevation measuring on the road and mtn bikes.
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Let's me use cheap Cateye computers on the bikes and still get elevation functions.

Cool. I hadn't thought of the Suunto's but that approach sounds good to me. I love my ancient Cateye Micro and plan on still using it. I was just going to stick the other computer on the bar and not even measure bike-stuff, but the Suunto sounds like a very good alternative to a bar-cluttering unit.

[rounder]

I just bought a specialized computer that measures altitude (wireless). It is still in the box so no idea yet how it performs. Am no moutain goat, but am curious about how big our hills are. Will let you know how it goes.

[nm87710]

FWIW, any model that uses atmospheric pressure needs to be calibrated at the start of each ride ride to be reasonably accurate. IME, if one does not take time to calibrate before each ride(sometimes also during a ride if temps change significantly) they are no more accurate than using google maps or similar online mapping tools.

Good Luck!

[weisan]

but Louis-pal, why bother to see what kind of damage those hills can do unless you can get over em'? :D :crap:

[Louis]

but Louis-pal, why bother to see what kind of damage those hills can do unless you can get over em'? :D :crap:

Weisan,

As best I can recall, YOU are the one who can't make it up the hills... :no:

[DavidR]

Louis - anyone who has ridden the hill to your house already knows it horrible!

[Louis]

FWIW, any model that uses atmospheric pressure needs to be calibrated at the start of each ride ride to be reasonably accurate. IME, if one does not take time to calibrate before each ride(sometimes also during a ride if temps change significantly) they are no more accurate than using google maps or similar online mapping tools.

Not a problem (I don't think) but perhaps a hassle:

I don't live far away from an airport. I can calibrate it there then drive / ride home. Do this say, three times and average the results. That will give me the altitude of my house. I can also get home altitude from various online sources.

As far as temp changes during the ride, I believe most are temp-compensated.

Edit: I should say that the altitudes of airports are measured very accurately (for obvious reasons) and are readily available. I can even walk in the door and ask them what the exact altitude is at each end of the runway...

Edit #2:

Registered Location
Latitude: 38° 39' 26" N (deg min sec), 38.6572° (decimal), 3839.43N (LORAN)
Longitude: 90° 39' 21" W (deg min sec), -90.6558° (decimal), 09039.35W (LORAN)
Elevation: 140 metres (462 feet) -- validated against 139 metres (455 feet) from NED 1/9th arc-second: Mississippi-Missouri-Illinois Rivers
Location: St Louis Spirit Of St Louis, MO, United States of America
County: St. Louis, MO
Forecast Office: St. Louis (LSX)
Airport diagram: PDF from FAA
Site Manager/Operator: Mr. John D. Bales (Tel: 636-532-2222)
Automated weather phone (ASOS): 636-536-3734
Observing program(s): LAND SURFACE ASOS ASOS-FAA LAWRS

Altitude data point #2:

FAA INFORMATION EFFECTIVE 29 JULY 2010
Location
FAA Identifier: SUS
Lat/Long: 38-39-43.6000N / 090-39-07.4000W
38-39.726667N / 090-39.123333W
38.6621111 / -90.6520556
(estimated)
Elevation: 463 ft. / 141.1 m (surveyed)
Variation: 02E (1990)
From city: 17 miles W of ST LOUIS, MO
Time zone: UTC -5 (UTC -6 during Standard Time)
Zip code: 63005

[Louis]

Louis - anyone who has ridden the hill to your house already knows it horrible!

Agreed :)

But given all that pain I go through every ride, I want to feel the satisfaction of seeing what the elevation gain for the whole ride really was.

[fourflys]

I have a Sigma Rox 9.0 and WOULD NOT buy another one... especially the altitude function, it's really hard to be sure if it's accurate...

[fourflys]

I think Cateye has a new comp out now that had altitude... hard to wrong with Cateye if you don't want Garmin...

[dogdriver]

At the risk of speaking out of turn, why bother with a barometric altimeter when you can buy a basic GPS unit with altitude function for less money and better accuracy? The only reason that "certified" aircraft use barometric altimeters is that the government (FAA) only certifies barometric altimeters to operate in their air space. A unit with GPS derived altitude always knows exactly where you are regardless of temperature, barometric pressure, day of the week, exchange rate of the Euro vs the Vietnamese Dong, etc.

We could drink a lot of beer (or wine, if you're arguing with Serotta Pete) discussing this subject, but consider this: commercial airplanes operating above 18000 feet (the "Class A", or "Positive Control Airspace") don't have any idea what their actual altitude is. Rather, everyone in the Class A sets their altimeters to the same barometric pressure (29.92 inches Hg), so that everyone has a common standard to measure altitude in relation to everyone else.

My $.02, Chris

[Louis]

why bother with a barometric altimeter when you can buy a basic GPS unit with altitude function for less money and better accuracy?

Off the top of my head, four reasons, not all of which may make sense:

1) Concerns (perhaps unfounded) that the GPS altitude accuracy is not any better than baro, and in fact, possibly worse. I'm not sure how GPS units calculate altitude, I assume by looking it up in a topo database given the calculated lat-long, and if that's the case I think all the rolling hills around here will result sketchy altitude numbers.

2) I don't want to be tempted by all the GPS toys and data. I don't want to turn my cycling into a science project and given all the data available on those things I would be tempted to do that. I just want altitude and maybe grade.

3) I previously had an early-generation unit (Garmin Forerunner) which was useless around here. I attributed the problem to the dense tree-cover on lots of my routes, since it seemed to work fine when I drove around with it, but I may be wrong. It also might have been shielding by all the hills, but I don't know the elevation of the various GPS satellites when viewed from St Louis and haven't bothered to find out. I'm pretty sure newer units are better, but I was burned once.

4) The GPS units I've seen are huge (IMO, compared to my Cateye Micro) and I just don't want something that big on my bars.

[akelman]

For what it's worth, I didn't like my Garmin 705 because of its size. But the Garmin 500 is only a bit larger than a standard computer. It also has a barometric altimeter, if that's what you're set on. And you can get them from either Nashbar or REI, both of which have lifetime guarantees.

That said, I'm not shilling for Garmin. Get what you want to get. But if the 500 has the features you want, you shouldn't shy away from it because of size. [Insert size matters joke here.]

[rustychain]

Not the answer your looking for perhaps but an iPhone or Droid have very good apps that will provide elevation and more and are easy for anyone to use. GPS uses triangulation BTW from 3 satellites. If you select an app like "map my ride" you can enjoy seeing a map of your ride with elevation during or after your ride. Also has a camera to take pics and even a phone for an emergency! ( you can turn off the ringer if you don't want to recieve calls). I frankly don't bother with a cycling computer anymore. Oh, one more thing. If you get lost ( something I kind of like to do) you can find your way home or find a nearby store for supplies :cool:

[1centaur]

The Garmin 705 uses a barometric altimeter because it's more accurate than the GPS-based one in the 605. That said, all altimeters will fail to accurately record the up and down 5 feet lumps of road riding that your legs will record, and if you speed down a 50 foot hill and up 50 feet on the other side you might not get 50 feet of climbing recorded because barometric altimeters use algorithms that look for confirming data points before recording their data, and a quick down and up might not give the unit time to get that confirmation. This is why you can try to correct total ascent with post-ride GPS software on the Garmin site, which in my experience almost always adds notable feet, but you are left wondering if their data is accurate, and when I asked the tech help at Motionbased they were not very helpful.

I spent a lot of time on a variety of computers watching my ascent change as I was riding (good things no cars were coming) and found NO computer as quick to record actual changes as the altimeter in the Garmin 705. Therefore I trust it best and don't use post ride correction, but in the end I have to accept it's an approximation that could easily record 1750 feet of climb when the reality is 1950. On my Greylock ride it recorded 2000 feet inclusive of ups and downs, whereas the map says absolute feet were over 2100.

[RADaines]

There seem to be a lot of options these days if you are looking for cycling computers that provide altitude measurements. Altitude seems to be the "in" feature right now. However, if you expect truly accurate and consistent measurements you will be disappointed and frustrated. I have been using a Garmin Edge 305 for the last four years and have come to accept that elevation data is not written in stone and there is a lot of inherent variability. Once you accept this, the data can be useful and interesting, just don't expect absolute accuracy. Units such as the Garmin Edge 705 and 500 let you manually set your starting elevation (if known) at the start of your ride. However, as I understand it, if the unit has not fully calibrated or settled, there can still be significant drift in the starting elevation. You have to accept these devices for what they are. I still find it amazing that these things can detect changes in atmospheric pressure that occur with changes of only a foot or so. Check out some of the VDO units, they look kinda interesting.

[gone]

I've got several VDO MC 1.0+ computers (Altitude & temp, no cadence or heart rate) and their altimeters seem pretty accurate based on two heuristics:

Calibrate at the altitude of my home, (777 feet), go for a ride and it's within a few feet of the starting altitude when I return.
Checked against a friends Garmin 705, both calibrated at my home before we start and our post ride cumulative gain was within tens of feet of each other. Did this on several occasions with little variation.

I wouldn't fly a plane using them but they seem pretty good for knowing how much I've suffered on a ride going up hills :D

[malcolm]

http://forums.thepaceline.net/showthread.php?t=78234

I had one of the VDO computers like this one and liked it. I don't recall if it had accuracy issues, but since I don't remember I assume they were in my favor and made things look harder than they were. I think I sold it to Gothard (George). It was a nice very solid computer.

[OtayBW]

I've got several VDO MC 1.0+ computers (Altitude & temp, no cadence or heart rate) and their altimeters seem pretty accurate based on two heuristics:

Calibrate at the altitude of my home, (777 feet), go for a ride and it's within a few feet of the starting altitude when I return.
Checked against a friends Garmin 705, both calibrated at my home before we start and our post ride cumulative gain was within tens of feet of each other. Did this on several occasions with little variation.

I wouldn't fly a plane using them but they seem pretty good for knowing how much I've suffered on a ride going up hills :D
I have a VDO MC 1.0+ as well, and mine doesn't come close to being within a few feet - or even a few percent - of the starting elevation, even on the 'best' day. Nice computer, but the altimeter is just fair, IMO.

[dekindy]

My Garmin 305 ascent numbers are grossly inaccurate. The software has an option to calculate altitude based upon a topographical map or the information would be worthless. Is there a way to get the information during the ride to be more accurate?

[RADaines]

My Garmin 305 ascent numbers are grossly inaccurate. The software has an option to calculate altitude based upon a topographical map or the information would be worthless. Is there a way to get the information during the ride to be more accurate?

I always turn my unit on and put it outside for about 20 minutes before I ride. Most times the elevation comes within several feet of where it is supposed to be. If I do this, my starting and ending elevations are usually pretty close (I am happy if they are within 10's of ft of each other). If the elevations are way of base, you may need to do a hard reset. This has worked for me in the past when the reading got way out of whack. I also would not be surprised if there is a lot of unit to unit variation. I have been fairly happy with my numbers but I know that some people have found their units to be highly variable and inaccurate. The other option is to buy the 500 (or 800 when it comes out) so that you can manually set the starting altitude.

[endosch2]

First, the Garmin 500 has a barometric altimeter - not GPS based.

Second, you can use a NASA based plug in to the open source software "Sporttracks" that will give you very precise GPS based elevations. This is highly accurate.

Spend some time on the BLOG "DCRainmaker" and you will get more technical knowhow of using Garmins and other stuff than you can find anywhere on the net. The sporttracks open source software is great.

[endosch2]

Here is my sporttracks graph from the Mt Washing Hillclimb in NH. The top is 6277 - I was using an Garmin Edge 500 - this is the altitiude chart with no add-ins on sport tracks - it is pretty accurate.

[dimsy]

I think Cateye has a new comp out now that had altitude... hard to wrong with Cateye if you don't want Garmin...

i believe this is the one you're referring to, i was looking at this one as well. i loved my old double wireless. i do hope they've gotten passed a little issue i had with the strada which was this unbearable rattling noise due to the nature of how a user would change to different parameters. clicking down the entire body after a while causes a little play in the device. this in turn lead to the rattling noise i encountered. other than that the unit functioned perfectly.

http://www.bikemania.biz/Cateye_Adventure_Wireless_Computer_p/cateye_cc-at200w.htm

[RADaines]

First, the Garmin 500 has a barometric altimeter - not GPS based.
Sorry this is not correct. The Edge 305, 705, 500 use GPS to set the initial elevation and track changes using the internal barometer. The Edge 205 only uses GPS to track elevation changes. Check out the Garmin forums as there is a lot of discussion surrounding elevation measurements. The unit has to determine what the initial elevation is some how. If you cannot input manually it must use GPS to set it.

[jbrainin]

At least with the Garmin 500, you can create start points with predetermined altitude measurements so that there is no GPS used. The new 800 works the same way. I would not be surprised if a new firmware update for the 705/605 adds this feature in the future.

[Ozz]

I have an old Avocet Vertech (ca. 1995) you can have for $25. It needs a battery...I have not used it for years.

It does not have the factory (plastic) strap...I put a velcro "The Band" strap on it for more comfort. See picture

Measures current alt., cumulative up, cumulative down, etc.

Let me know if you are interested.

[dogdriver]

Edit-- Oops-- my "quote and paste" skills are obviously lacking. The numbered paragraphs are Louis' entries, the paragraphs that follow each of Louis' are mine.

Computer illiterate, Chris


Off the top of my head, four reasons, not all of which may make sense:

1) Concerns (perhaps unfounded) that the GPS altitude accuracy is not any better than baro, and in fact, possibly worse. I'm not sure how GPS units calculate altitude, I assume by looking it up in a topo database given the calculated lat-long, and if that's the case I think all the rolling hills around here will result sketchy altitude numbers.

No database involved. A GPS signal has 4 bits of info in it: X,Y,Z position axis (latitude, longitude, elevation), and time. All additional data you get (velocity, distance, elevation change, grade, etc) is determined by your receiver and its software. Altitude (the Z axis of position, actually elevation from the center of the earth converted by your box into altitude above sea level) is just one ingredient of the signal. The signal is bulletproof accurate (read-- dropping a GPS guided bomb down a ventilation shaft of a building with the same signal your bike-mounted GPS uses). The accuracy of the data presented to you is the product of the unit you have.

2) I don't want to be tempted by all the GPS toys and data. I don't want to turn my cycling into a science project and given all the data available on those things I would be tempted to do that. I just want altitude and maybe grade.

My temptation also. I tend to turn into a bit of a geek around technology (the main reason I don't have a web-enabled cell phone yet). In an effort to limit the distractions (and crashes), I have the front page of my Garmin 305 showing 4 items: speed, time, distance, and elevation change. From what I remember, you can customize from 1 item to 12 displayed items out of a menu of 40 or so, as simple or complex as you prefer.

3) I previously had an early-generation unit (Garmin Forerunner) which was useless around here. I attributed the problem to the dense tree-cover on lots of my routes, since it seemed to work fine when I drove around with it, but I may be wrong. It also might have been shielding by all the hills, but I don't know the elevation of the various GPS satellites when viewed from St Louis and haven't bothered to find out. I'm pretty sure newer units are better, but I was burned once.

Agreed. A GPS satellite signal is a pretty fragile line-of-sight signal, and any obstruction (trees, buildings, large rocks, etc) will interfere with it. One of the reasons that most units look for 6 satellites, when only 3 are required for the triangulation math. I get "signal lost" beeps pretty regularly in the woods, they usually last a few seconds. The good news is that any GPS unit will update the next time it receives a signal and extrapolate the "lost time". However, one has to assume that the reception quality of a $200 device won't as high as a $50,000 unit.

4) The GPS units I've seen are huge (IMO, compared to my Cateye Micro) and I just don't want something that big on my bars.

True. Agreed. A lot of stuff packed into those boxes. For small, I'm thinking one of the altimeter watches. Maybe the Avocet in this thread. Several of my skiing (and a few glider) buddies have them and think they work fine.

Lots of complaints on this and other threads regarding personal altimeters. I've been using a second-hand 305 for two years and am pretty impressed with the data. Daily elevation changes (all I really care about relating to altitude functions) seem very accurate. Maybe I got a good one...

[jemoryl]

I have one of those Mavic Alti computers shown on the first page (although mine is the previous generation without the USB port). The barometric altimeter seems to work pretty well. You can store your 'home' altitude and load it or enter the starting altitude wherever you are. For cycling, it really doesn't matter too much, since most of us are just interested in the gain over the course of a ride (relative measurements), not the absolute altitude (would matter more in a plane).

Having said that, I probably wouldn't pay full list price for one of these things. Got mine new for about $60 when Nashbar had them on sale plus a 20% coupon. My old computer crapped out and I figured what the heck... I have grown rather fond of the Mavic wireless sensor which replaces the quick release nut.