Road sprinting and track sprinting are not the same thing. Cavendish and Viviani are sprinters on the road. On the track they are considered Enduros. An Elite track sprinter will produce in the range of 2,200 or more Watts. I was told Chris Hoy would hit 2,600 Watts. For track sprinting at an Elite level, you have to be massively strong. To compare track and road sprinting is apples and oranges.

Just to add some levity