Originally Posted by carleton

Any max speed data from GPS devices are suspect. Only AVERAGE speed data is someone reliable.

Unless you have a speed sensor on your wheel AND you direct your head unit to ONLY read from the speed sensor (and not the satellite), your max speed data is suspect.

Basically, the GPS unit is GUESSING your speed based on where you are in relation to the satellite.

I've had the GPS speed thingy on and my bike was leaning against a tree...and the Auto Start/Stop alert kept sounding. I looked at the GPS and it said the bike was traveling 10mph.

60mph IS possible. But those are the kinds of speeds that TDF racers hit when descending crazy mountains.