TheRCF

I would really like to find out how much of a climb the various hills are on my routes. Most of them aren't real long - half mile or less for a lot of them, a couple a mile or so, and one goes on for 5 miles.

I know a GPS unit might have an altimeter based on satelite readings and others use a barometer. But GPS units are expensive and I really don't need anything but the altimeter.

There are also watches that give an altimeter function - I think all are based on barometric readings. Some of these include other bicycle computer functions (speed, odometer, etc). They seem to cost less, though some are pricey.

So, just how accurate are these various altimeters (plus/minus how many feet)? And are there any that people could recommend?

Bob

Cyclist0383

VDO make cycle computers with Altimeters.
https://www.cycleparts.de/en/produkte...10/funktionen/

scarry

Cyclecomputers with altimeters are not cheap. I have the Ciclosport HAC4 with speed, altitude, heart rate and computer download, which allows you to plot your rides.

It's way cool, but cost as much as a bike.

HiYoSilver

There's a new one coming from Germany this fall/winter that calculates the grade automatically for you. I think it may be ciclosport something. Release was delayed, Price is up there, reliability records are mixed. But if this is what you're looking for, it could be the cat's meow.

ROJA

I have the Cateye and it is about $100, including altimeter and thermometer. It seems to work pretty well so far.

TheRCF

I checked the VDO stuff - nothing there about how accurate it is. I really need to know that to decide if I want to spend big bucks.

Haven't found that info for the HAC4 either, though I notice Performance has them on sale for $209.

If the comments about setting it properly (calling the weather station or something) simply has to do with getting the correct altitude, that isn't a problem. I ride right through Waikiki so finding sea level is really easy!

TheRCF

Do you have any info on how accurate the Cateye is? If the documentation doesn't specifically address this, I guess one way of getting a rough idea is what range of numbers you get for a given point over a series of days (making sure you have it properly set to begin with each time). I mean, if you calibrate it before starting and go to a point where you previously had a reading of 100 ft, maybe over 4 more days you get numbers ranging from 95 ft to 105 feet. Therefore, you could say it is within +/- 5 feet for that point anyway. More measurements give a better idea.

scarry

The HAC4 by Ciclosport that I have had for 3 years calculates the grade %, and in the computer printout, also calculates your ascent/decent rate, ft.per.min., your power output, watts. Works good, no complaints. The altimeter printout is nice, gives you a nice printout of your ride profile. It's good for estimating your fitness level by comparing speed to heart rate over a given course.

scarry

The min resolution is +/- 10 feet on the HAC4. The absolute elevation changes with the weather, (barametric), so if you want accurate absolute readings you need to calabrate it to some known point of referance, like your home. I've seen it change several hundred feet in a day with severe weather changes.

TheRCF

Just to make sure I understand, by minimum resolution, do you mean the BEST it can do is be within 10 feet?

I know weather can affect things but probably for the most part, it wouldn't make much difference on my rides, as long as I set it before I start. Like I said, most of my hills are short so there isn't much time for change.

However, that one 5 mile climb takes almost an hour and since it is moving into the mountains, where most of the rain gets dumped here, that one may be affected.

Jarery

IM a skydiving instructor in my other life, on the weekends. I have several altimeters i have and ocasionaly take one with me to measure the climbing i do.

https://www.usairnet.com/cgi-bin/skyd...meters&lid=100

Those are typical ones used in skydiving. Almost every city has a skydiving drop zone somewhere not too far away. Call em up, and see what they sell just a basic altimeter for. Might be able to get one for $50-$100 bucks. It wont be fancy or come with cycling functions, but it'll tell you your altitude.

TheRCF

I never thought of that. As long as it is small enough to carry around, I don't really need it much since I mostly ride the same places every time. Once I check the altitudes for each hill - maybe 2-3 times for consistency sake - that's about it. I don't need hardly any of the things your link showed. I just need to have it tell me the altitude for where I am at the moment. I can write it down for each hill and plug the numbers into a computer later since there is minimal change in where I ride.

However, from what I could make out from the link you gave, it seems that some of them, at least, give pretty big increments - like 250 feet - and I guess you make your best eyeball estimate of where in that range it is. These are the analog ones with a dial. Are the ones with a digital readout really accurate. After all, I would guess that in an airplane for skydiving, whether you are at 1000 feet or 1050, it makes minimal difference. But if you are riding up a hill that is only a half mile long, the altitude is very limited in how much it will change. So something that is +/- 20 feet might be a substantial factor.

Jarery

They are all barometric devices.They are only accurate to probaly 50-100 ft.

They are made mainly to be quick devices, since were doing up to 300 mph change happens rapidly.

Digital ones would be a bit more accurate since they take the guesswork of where the needle is. THey would be accurate enough to tell you the change in altitude you do.

Thats how I use mine for biking. I may be out by 100 ft in reality, but im out that 100 ft at the top and the bottom, so the change in altitude is fairly accurate. You'll just have a hard time discerning a change of less than 100 ft or so. Just another option for you to pursue.

Jarery

I just noticed, your on Oahu.

Dillingham airfield, up on the north shore will have them. I Have gone there for skydiving vations before. Nothing like waking up on the beach of Oahu, skyding all day, drinking all night, repeating till 2 weeks is up.

There is several skyding companies, situated at opposing ends of the runway there

scarry

Minimum resolution means the smallest measurment it will display is 10 feet. I generally climb a thousand feet or more on long rides, so 10 feet is not important. For example 1255 ft is displayed 125 (x10).

TheRCF

I don't get to that area much - I don't have a car and so I do everything by bike - that's a long ride with lots of climbes. But I'll get there eventually!

Bob

Cranks

Hey, RCF -
Here is a shot of a ride that I did on DeLorme Topo USA - Tantalus Drive roundtrip from Wilder and Makiki. I got the West Coast edition - $50, with a 30 day free trial.

You can map your route, get the GPS coordinates along the way, and look at the elevation at any point, as well as get a profile. Moving your cursor along the profile, you can see on the map the corresponding point, and figure out what the elevation is at that point. (Notice in the profile map - the blue line points to where I am pointing - elevation 1,630 feet (!), and on the maps you can see the corresponding point).

You can also print our cue sheets of the ride if you are interested in sharing the directions with other people. It's not very bicycle specific, and not too good with trails, but for road riding, it's nice to profile a ride ahead of time.

TheRCF

Am I missing something? I didn't see any "shot" of the ride - just your text.

I need to look into that software though.

Bob

steveh2

If you are most interested in figuring out elevation gain for a couple of specific rides, you can always buy topographic maps for a few bucks apiece.

Also, Google Earth -- which is free -- will give you satellite photos of the roads you ride and elevation info.

TheRCF

I have such maps, but they aren't good enough - often, especially on steep areas, it is hard to tell which line is which, plus estimating gapes between lines - and it seems amazingly often that some text is printed in just the wrong place so as to obsure things further!

HiYoSilver

Ciclosport.de HAC 5 was the new product I was thinking of. Looks like not available yet.
You might have to add it to a Christmas wish list.

HiYoSilver

USA distributor has the best feature list, but I'd wait for the HAC 5.
https://www.ciclosportusa.com/hac4.htm

HiYoSilver

CM 434 if don't need heart monitor

Cranks

Nope, other than the fact I am a total idiot.

I took the screenshot quality way down to make this fit, so if you notice even the Windows Toolbar is crappy. It's actually a good resolution before I hammered it with my JPG editor. PM me with your email address and I'll send you a better screenshot.

scarry

BTW the ciclosport usa support is not that great, although they did finally send me a replacement heart rate belt after mine crapped out. Turns out you can use a Polar brand belt as a replacement.

The battery change for the main unit is not for the faint of heart, but I'm an EE so I can do it OK.
Some tiny springs that can be easyly lost.
Also the software for the PC is hard to understand the installation (drivers) because the manual is poorly translated, but I managed that too, being used to Siemens equipment.