Originally Posted by
Iride01
Map data doesn't cover every square inch of your travels with an accurate elevation number. A barometric altimeter will cover every square inch of your travels, but it has various limitations too that will always make comparing one to another silly.
If you need to know something related to grade or gain/loss, then the average of many rides will give you the best numbers.
yes they can be slow. like I have a block that is 20% grade no way the altimeter can keep up with it.you need maybe 3 blocks.I have a lot of those one or two block hills.