This is interesting:
http://cyclingtips.com/2016/04/by-the-numbers-what...
"The final sprint on the famous Roubaix velodrome was going to require an all-out effort, close to any peak power he had done in the previous six hours of racing. In the final push to the line Hayman produced a 44-second effort averaging 641W (7.8W/kg) with an eye-watering maximum of 1,234W (15W/kg) as he made his final kick for the line, from the front of the lead group.
Breaking down this data even further we can see he did 935W (11.4kW/kg) for 20 seconds as he came off the final bend and into the finishing straight. And all of this after 255km in the hardest one-day race in the world."