Welcome Heraclitus!
I am very familiar with Los Angeles and especially with the Silverlake area since I once lived in East Hollywood. Alot of my friends lived up in the hills of Silverlake when I was in junior high, high school and community college before I went away to the university. My family still owns property in Los Angeles.
For travel with the folder, I have used both folders (Dahon Boardwalk and Brompton C Type) on the new light rail system as well as the nonfolding 26" Phillips with no problems. The Brompton was the best in terms of fitting in the tightest spots-see Brompton Found! (Nothing Like I was Expecting) thread for more information on it's purchase and trip home. The MTA buses are another matter. Although I have taken the bus with the Brompton hidden in it's bag, with the extreme crowding that many of the lines are experiencing, I find that I rather ride the bike to my destination as I have done even before I purchased my first folder. The bus drivers sometimes bump you off (do not let you on) if the bus is very crowded. And the bike racks are usually full.
The only place that I know about that sells both a Birdy or a Brompton is Nautique/Folding Bikes West in Oceanside. The owner is very knowledgeable about both makes. I purchase the Brompton there and never regretted it (she even sent me the owner's manual in the mail the next day after she forgot to give me one)!
The folders can be both modified to fit taller people. You might have to add the telescoping seatpost to the bike, but it will be worth it to your knees. As for gear range, the three speed hub (with the right diameter of chainring) allows for most grades of terrain encountered. The hills surrounding the northern area of Los Angeles is rolling and sometimes steep, but the range is fine for me and I rarely have to walk the bike up). Make sure you are comfortable about it by actually trying it out before you make the purchase.
The reasons why you want a folder is very similar to mine. For the past 2+ years, I have been increasing my bike riding because the bike stays with me all the time and almost eliminates theft. I love the small wheels which offer much more manuvering, control, and quicker acceleration than a larger wheel bike. I hope you enter the world of folders with the same excitement as I have when I bought my first one. I am sure you will not regret it.
Please write and let us know what you have chosen to ride.
Last edited by folder fanatic; 03-02-06 at 07:54 PM.