I'll throw my 2 cents in here and say if you have 3rd world roads like the roads in L.A. then you better buy a heavy duty bike cause those roads will destroy a cheap bike. High speeds and the added weight of all the stuff bolted to it will stress a cheap bike to it's limit. You will can away with a lot though if the roads are autobahn smooth. The roads condition that you travel on will determine how long your bike lasts or doesn't last. Every rut, bump, crack, and pothole is greatly amplified as your speed goes up. Get a bike with wide wide tires and at least front suspension if you can afford it.