On the downhill sprint, the road flattens out a bit but is still (I would guess) around 6-7 degrees. It is also after a good downhill stretch so when you hit the bottom you're doing 70 odd km/h anyway and you just need some serious leg speed to push it over 80. I don' t recall there being any wind. It was literally a 1 minute, max-out, balls to the wall effort off an already fast pace. I can't take credit for it, but I did pull about 10m on the guys who were racing me down the hill, so I wasn't just the decline and the wind. <br /><br />The other time, on the flat, I was trying to get into the draft of a car but it was about 15m in front of me, so I gave it everything I had. Didn't manage to close the gap to much closer than 10m, and when we finished the ride, my max speed was 80. I actually didn't realise it on the bike, it was just one of those really good days, where your legs feel like they're floating. Not a speed I expect to get to in a flat sprint too often I would imagine. (Unless I get my 54 that is, I hope)