get some snap loose straps and put them on your pack..nothin worse than not bein able to get to your bow fast...
i also dislike the bow rack on bikes..esp after i crashed and burned one day in the late season.. 
if your gonna crash, your gonna crash and doesn't matter where the bow is when you do. the outcome will not be good. that is unless your like a ninja and land on your feet before you hit the ground.
I agree 100%, I have seen both ways in a crash and the bow was damaged both ways. Coming from a racing background, I would want to be able to get away from my bow/bike in a crash. Not having a bow strapped to my back.
I say whatever method you go with, take trail runs on a local trail and find out what problems you run into and fix them before you go out into the woods. Try to buy the best equipment you can afford. I have seen guys with broken forks, bent forks, stripped out handle bar mounts, fried break pads...etc. Logging roads and mountain trails are rough on a bike and you can save a lot of headache with a little prep. I always make time after my day of hunting to go over ever bolt and "clean up", lube and inspect the bike for the next day, it only takes 15-20 mins this allows me to spend more time hunting instead of trying to fix something in the woods
One more thing,don't forget the heavy duty inner tubes!
