Alright, it's official, I'm going to get one. Mainly because myself and a friend of mine have a difference of opinion about the highest point on a particular ride, and I see this as the only gentlemanly way to settle it. Well, I guess there are other reasons, such as confirming or denying the "4,000 metres of climbing" claim someone made at the Glorious Mee ride last year, and putting on some impressive numbers on the Great Alpine Road in November, and... Ok, so you get the idea.

Does anyone have any recommendations in this area? Right now I have my eye on the Cateye Altimeter Cycle Computer because other Cateye computers I've used have always worked pretty well (one even recently went through my washing machine and survived). Anybody used one of these before?

Small electronic barometric pressure altimeters of the kind typically found on watches and cyclocomputers are notoriously inaccurate. You might want to consider one of the cheaper GPS receivers instead. To date, I haven't seen one on a cyclocomputer though.

Khuon..I have a simple Casio Forester I regularily sells for $130. On sale for $80.It will vary relative to sea level...But, when measuring a climb for a specific location. It repeatedly has no significant change as to elevation difference.

Another thing about barometric altimeters is that they can become inaccurate due to calibration drift when the weather conditions change. Pilots know to regularly reset their altimeter calibration... oftentimes by listening to ATIS, ATC or an FSS weather report for the area within an immediate 100nm of their position. On the ground, when climbing and descending near mountains, you may encounter some steep pressure gradients simply due to the terrain's influence on the atmospheric conditions which can throw off your altitude readings.

How much variation would there be likely to be over the course of a ride?

There wouldn't be very much variation in the span of a few hours, it would probably only make a difference of a few meters in your altitude. That's if it does actually vary enough to make a noticible difference. You could check the air pressure before going out and set the altimeter, and if updates were required while out you could carry a radio scanner to check. That could be going a bit over the top though

What I intend to do when I get it is walk from the beach to my place, so I know the exact altitude of my driveway. I can then reset it to the three metres or whatever it is for the start of each ride. Of course, that option may not be available on the Great Alpine Road in November, but we'll see.

I've been happy with the wireless Vetta V100A I purchased last year. With respect to calculated elevation gain over the course of a ride, I've compared it to other sources of elevation info (an older Avocet Vertech watch, and route mapping with Topo USA 4.0). The Vetta seems to produce the best results of the three (higher than the Avocet which has a higher "trigger" point, and lower than Topo USA which notoriously overstates elevation gain).

It also features a real-time Grade Percentage display. This is interesting, but sometimes gives funny numbers (too high). Over the course of a climb, the Grade Percentage is mostly OK, but you can't always believe the Max Grade number at the end of a ride.

Specialized also makes a computer that does elevation gain, and I've heard some good reviews on it too.

BTW, it's my understanding that GPS units are not very good at calculating elevation gain.

Good enough to get approved in many cases for the 200' decision height on precision approaches... It depends on the unit. The Garmin, Magellan, Lowrange and Morrows are pretty accurate.

I use the Garmin GPS-12 when I am looking for elevation measurments. I also use it to map out routes and to insure my bike computer is "near" accurate.

EDIT: The only function it does not do that I would like is to record the elevation changes with the route. Or even total elevation gains/losses etc...

I have the Cateye with altimeter. I think it is reasonably accurate for altitude readings, but I think for accumulating climbing altitude you have to keep it set on the altitude mode all the time. I would rather have one that also gives a gradient reading.

Another option: I have a Suunto watch that provides altitude (which I use), and barometric pressure and a compass (which I don't use), besides the normal watch functions.

It's pretty cool for skiing or bike climbing, if you do repeated runs. It'll keep track of how many runs you've done AND the cumulative vertical meters. I set it when I start the day on the ski slopes, and can see exactly how many runs and vertical feet I did when I finish.

I've used it to figure out the elevations and climbs I do on all my "regular" training routes.

That's an interesting point. Does this thing stop counting climbing when it's not on the altitude mode? That would seem a little strange -- given that virtually every computer I've ever had has continued to count distance on other modes (such as average speed and so on). I too would like one with a gradent reading, but that might be a little beyond my budget at this stage.

I know some of the specialised computers have an "inclinometer" to show the gradient. The top model ("turbo pro" i think it is) is somewhere around the USD$100 mark. Worth it if you have the money I think... that's what I'm going to put on my new bike once I get it.

I agree, Delorme does too, I think the issue here is often these are measuring ungraded land and roads are graded. Any bridge you cross will greatly exagerate total climb. For us, the Foresthill bridge (the one the Corvette is driven off in XXX) throws off climbing elevation by 800ft alone when measured by Topo.

I use the Ciclosport CM436, and it seems to be pretty consistent in its altitude readings. I looked at topo maps to find the altitude of my house, and always set it to that before leaving on a ride. I recently got a GPS too (I am a *total* data geek) and I find that my CM436 agrees with the altitude from my Garmin Geko fairly consistently. Only difference is that the Geko takes a while to get a good fix on the altitude sometimes.

I agree with some of the others who have already replied to this thread. Get yourself an inexpensive GPS unit like the Garmin 12. You will quickly find that it can be an invaluable tool that will give you an accurate altitude in MSL, but also gives you lots of other useful info as well.

Randy

But, aren't GPS units:

1) bulky (when compared to other alternatives)
2) not good for recording "cumulative elevation gain"
3) battery inefficient (would the batteries last on a typical century ride?)
4) subject to satellite drop-outs due to trees, mountains, etc.

I have a handheld GPS, but don't take it on rides for these reasons. But, it's a couple of years old, so maybe some of these issues have been resolved?

I got my little Geko basically to do stuff like download a tracklog of where I'd been post-ride. It's a fun little device, but, referring to the points above:
1) I got the Geko because it's only 3 oz, smallest such unit I've seen.
2) Yes, I haven't seen cumulative elevation recorded on a GPS.
3) Batteries tend to last as little as five hours.
4) You definitely get this problem under tree cover. Haven't noticed problems with mountains/ hills.

You might consider the Garmin Forerunner 201. It's light, wearable, lasts 15hrs on batteries, has slope and elevation tracking...

Here's a review...

https://www.tramsoft.ch/gps/garmin_forerunner201_en.html

The Gecko 301 also has nice elevation features...

https://www.tramsoft.ch/gps/garmin_geko301_en.html

Both of these units are fairly compact.

The only downside seems to be the battery life. I'm planning on using this for my tour later in the year -- and I'm not so sure I'll get the opportunity to recharge/obtain batteries all that often in the really mountainous bit.

Yes, that can be an issue. The ForeRunner 201 uses rechargable batteries... this might be a possible solution.

When my ears pop, I'm too high.

(my 1.5 cents, not worth saving. )