# Cateye Adventure (CC-AT200W) altimeter problem

• 07-23-11, 01:52 PM
Redwood26
I just bought a Cateye Adventure mainly for the altimeter. After it was installed, it showed an altimeter reading of 220 feet even though it should have read 345 feet (my house elevation). I corrected it. Next day I took it to the mountains above 5,000 feet, and it still showed a reading of 345 feet. Shouldn't the altimeter showed an altitude of 5,000 feet? When I started to ride, it correctly showed an increase in altitude from the 345 foot mark. At the end of my 1,000-foot climb ride, I corrected the Cateye to 5,000 feet. When I returned home, it still showed an altitude of 5,000 feet.

I took it back to the store, and they exchanged it. But the new unit did not show any change in elevation from the store to my house, which there is a difference of at least 200 feet or more.

Any thoughts?
• 07-25-11, 12:43 PM
mulveyr
Quote:

Originally Posted by Redwood26
I just bought a Cateye Adventure mainly for the altimeter. After it was installed, it showed an altimeter reading of 220 feet even though it should have read 345 feet (my house elevation). I corrected it. Next day I took it to the mountains above 5,000 feet, and it still showed a reading of 345 feet. Shouldn't the altimeter showed an altitude of 5,000 feet? When I started to ride, it correctly showed an increase in altitude from the 345 foot mark. At the end of my 1,000-foot climb ride, I corrected the Cateye to 5,000 feet. When I returned home, it still showed an altitude of 5,000 feet.

I took it back to the store, and they exchanged it. But the new unit did not show any change in elevation from the store to my house, which there is a difference of at least 200 feet or more.

Any thoughts?

I have an Adventure, but I've never checked the elevation when not riding. It probably doesn't update the display until, as you noted, it senses that you're moving. Which, if you think about it, would make sense, as that would be the conditions under which it can calculate the slope, as well.
• 07-25-11, 08:48 PM
Redwood26
update
Quote:

Originally Posted by mulveyr
I have an Adventure, but I've never checked the elevation when not riding. It probably doesn't update the display until, as you noted, it senses that you're moving. Which, if you think about it, would make sense, as that would be the conditions under which it can calculate the slope, as well.

I called Cateye, and they told me it does not calculate altitude unless it detects motion. But my concern is that it does not correct itself on the next ride. I took my bike in my truck to the river at 90 feet and then started a ride, and of course, the altimeter showed 345 feet and continued to measure from that base of 345, so during the two-hour ride along the river, I had no idea of the real altitude of that ride. Cateye said that I would have to re-enter the new altitude for every ride unless I always rode from my house. I'm still not sure of the purpose of the home setting if the altimeter only shows the last time the computer was in motion? Finally, the Cateye web site says that this unit has a "fully functional" altimeter. How can they say that if it does not tell you the current altitude, even after you start riding?
• 07-25-11, 09:21 PM
mulveyr
Quote:

Originally Posted by Redwood26
I called Cateye, and they told me it does not calculate altitude unless it detects motion. But my concern is that it does not correct itself on the next ride. I took my bike in my truck to the river at 90 feet and then started a ride, and of course, the altimeter showed 345 feet and continued to measure from that base of 345, so during the two-hour ride along the river, I had no idea of the real altitude of that ride. Cateye said that I would have to re-enter the new altitude for every ride unless I always rode from my house. I'm still not sure of the purpose of the home setting if the altimeter only shows the last time the computer was in motion? Finally, the Cateye web site says that this unit has a "fully functional" altimeter. How can they say that if it does not tell you the current altitude, even after you start riding?

I think you're expecting too much of it. :-) In order for it to work like you're saying, it would have to continuously monitor the pressure, even while in sleep mode, since atmospheric pressure is constantly changing, and would thus have to be tracked. I.E. the computer doesn't have any way of knowing the difference between the pressure dropping because of purely atmospheric changes, or because you're ascending, unless it also detects that you're in motion.

If it did continuously track pressure in the absence of motion, that would absolutely kill the battery life. Even small aircraft pilots need to reset their altimeters when they're about to take off, for much the same reason ( and they're often purely mechanical devices ).
• 07-25-11, 10:09 PM
Redwood26
Quote:

Originally Posted by mulveyr
I think you're expecting too much of it. :-) In order for it to work like you're saying, it would have to continuously monitor the pressure, even while in sleep mode, since atmospheric pressure is constantly changing, and would thus have to be tracked. I.E. the computer doesn't have any way of knowing the difference between the pressure dropping because of purely atmospheric changes, or because you're ascending, unless it also detects that you're in motion.

If it did continuously track pressure in the absence of motion, that would absolutely kill the battery life. Even small aircraft pilots need to reset their altimeters when they're about to take off, for much the same reason ( and they're often purely mechanical devices ).

First, thanks for taking the time to respond. I'm not necessarily upset about this as much as perplexed and fascinated.
Now, when I took it up to 5,000 feet the other day, this unit showed I was starting at 345 feet even when I rode for two hours. I climbed 1000 feet, and the end of my ride it showed an altitude of 1345 feet. So this altimeter did not detect the pressure of over 5,000 feet even after two hours in motion at that altitude?

So what I think you are saying is that this unit is not really an altimeter that detects the current altitude, it simply tells you the change in altitude when it's in motion.

Thanks again!