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Setting Elevation

Posted: Tue Oct 21, 2008 11:29 pm
by cjonbike
I have a question. Depending on which software or which site I go to my starting elevation according to these sources can vary up to 100 ft. If I really do not care what elevation I am riding at can I just set my iBike to 0 ft and would it give me the same data as if I set it at 4500 ft in terms of power and climbing?

I do thank you for your input

Chris

Re: Setting Elevation

Posted: Wed Oct 22, 2008 6:30 am
by Velocomp
It makes no difference what starting elevation is set in the iBike. The change in elevation from point to point is what is important and the iBike will measure that number with high accuracy.

Re: Setting Elevation

Posted: Wed Oct 22, 2008 6:34 pm
by scotty
John,

Concerning the altitude accuracy, I would agree that it is accurate. But I do have a question, I ride a recovery route that is the same a couple of days a week. Most times the accuracy of elevation is within 20-30 feet over the course of the ride. Occasionally though I will get an descrepancy of 300 ft or more.

Before each ride I routinely set the wind offset, the tilt calibration, and even reset the altitude. Do you have any idea what would create these differences on that rare ride when the descrepancy is so great.

Re: Setting Elevation

Posted: Wed Oct 22, 2008 7:41 pm
by coachboyd
If you set the elevation right as you ride, changes in barometric pressure can cause that number to change. There can be other explanations as to why barometric pressure changes during a ride (storm moving in, temperature changing, going between clouds and sunlight) I have found if I stop at a store and leave my iBike in the direct sunlight, it can effect the barometric altitude.

But if your house and the outside temperature is different, and you bring the unit outside and do set the altitude, you can get variance in your ride.