in bryn mawr a ****ty cable lock will certainly do the trick. i live in a similiar neighborhood and a cable lock does the trick, i also use it in the city and have had no problems but my bike is old and rusty and not worth the effort.
with your bike i would be very serious about locking it up, bike theft is rampant so i would suggest a krypto u lock and a solid cable lock for stops any longer than an hour