It's unrealistic to be able to maintain that kind of speed for that distance in downtown city traffic...I live in the suburbs where it's more open and it's impossible to maintain that type of speed for that distance because of traffic lights, wind, changing road conditions, hills and other things...Remember that this is bikeforums where "anything is possible". People can make all kinds of outlandish claims...but the reality is different...A lot of stuff that's posted here is to be taken with a grain of salt, internet is more about entertainment then reality.