Record speed for me is 29.8 MPH on my fixed gear commuter with 69 gear inches. I can do that for only about 8-10 seconds on flat as a pancake road with no wind...I am guessing my cadence must of been around 144 rpm's and I just spin out and need to slow down. This was done while wearing a backpack, carrying a heavy lock and being a little tired from working all day. My bike is not set up for sprinting, it has fenders , front rack and non-racing tires...