I use my Edge all the time on my mtb. Works fine, although I do occasionally have reception issues. Of course, it could be that I ride so slowly, it thinks I'm stopped and shuts off! 
As others have said, it should be fine. I've skied with it in my jacket pocket and it worked fine for tracking my runs (I did that just for giggles to see if it would work..it did). So, it does receive fine in a pocket, too.
2007 Seven ID8 - Bontrager InForm
2003 Klein Palomino - Terry Firefly (?)
2010 Seven Cafe Racer - Bontrager InForm
2008 Cervelo P2C - Adamo Prologue Saddle