One man's fast is another man's slow. If you posted a lap of Donington good enough to put you on the third row of a MotoGP grid your mates wouldn't hear the end of it, but Rossi would be gutted. For some cracking the ton is enough; for others that's just warming the tyres.
Of course going fast isn't just about straightline speed. Anyone who has given an R1 or Blade its legs on a motorway will have gone faster than, say, a top motocross rider doing their day job, but try going head-to-head with him on his own turf and you'd see nothing but dust - 70mph across a rutted field can feel like 200mph on the road. Likewise, most riders would be able to reach 180mph or more on a two-mile runway, but it takes a different kind of bottle to travel that fast through built up areas on the TT course.
So what's going on in the minds of the truly fast? Can they really have time to think when they're travelling at speeds the human brain wasn't designed to deal with, or are they simply prepared to chance it more than us and hope for the best? Masters of various two-wheeled disciplines reveal what going fast means to them.