Originally Posted by Trsnrtr
I've heard, but don't really know, that handheld consumer GPS units usually under read distance by "staightening" out curves and corners due to averaging. Bike computers, when calibrated properly, measure actual distance traveled by the wheel.
We have a licensed land surveyor on staff. Maybe I'll pose this question to him on Monday.
Cyclocomputer distance travelled will always be more accurate than GPS.