Before today, the top speed on my bike was 49.9km/h (31.00mph). This really annoyed me, because I wanted to get to 50, a nice even number.
Then, today, I had the wind behind me, and was going down a small hill. It wasn't steep, I go up/down it every day. Anyway, I managed to get up to 55.4km/h (34.42mph) :-)