There are definitely areas to avoid as there are anywhere. Just find one of the shops around you to help you with where not to go. I ride in Vestavia out towards Liberty Park and even east towards Shoal Creek. I am more risk adverse when it comes to driving on busy roads. Way too many drivers that will clip you around here. I like Bham for riding, but I haven't searched out enough rides that flat aside from a few rollers. Feel free to ask any other questions about Birmingham.