Hey all, I'm looking to buy a new bike to ride around my area (sidewalks, roads, streets, etc..). I go riding at least 5 times a week and would like to hear some recommendations for a new bike. My budget is <= $300 and I would like something relatively lightweight and quick. I want the bike to be rather comfortable so I would be able to ride more than 30 minutes without getting major arse cramps, but I guess the saddle can be replaced if need be. I also don't want it to break down on me in a few rides. I weigh about 140 pounds and am around 5'7'' in height. All recomendations will be greatly appreciated, thanks.