Originally Posted by CrimsonKarter21
Wait, does the Edge 305 have a speed sensor or no? I was under the impression that you could just attach the head mount to the bike and ride, GPS told you how fast you were going, no magnets or speed sensors included.
The speed sensor is optional and is combined with the cadence sensor. The GPS odometer is very accurate, except in some deep canyons where you lose the GPS signal or when you are riding indoors on a trainer. Personally, I do not use the speed sensor and don't miss it.