Assuming all things equal at pro level. Which is these racers are fitter ion general. I know this will start a crazy discussion.
My opinion is a Crit racer ( seems to be more well rounded. Explosive power, sustained power, vo2 Max, Awesome bike handling skills. High power for long periods of time.
Define fitter.
I also think you have a few fairly arbitrary distinctions.
Comparing crit racers to road racers to tt racers - that’s fine I guess - they all have different attributes required but they are all different types of races so it is sort of apples and oranges, but at least they are the same basic category
Same for comparing climbers to sprinters - it’s different types of racers not different types of races. So kind of apples and oranges again…
But comparing a road racer to a sprinter? Now you’re comparing apples and basketball shoes. I’m sure both Marcel Kittel and Adam Yates consider themselves road racers but one of them would absolutely murder any crit you threw at him and the other wouldn’t
If all things are equal then they are all of equal fitness.
My meaning by all things equal is to say they are all of the same age, all elite world pro cyclist, same experience level. Not comparing 1 1st cyclist on the national team compared to a seasoned uci world team cyclist. Not someone that all they have ever done was Tour of Utah compared to a season Tour de France or Giro racer.
If you wanted to put a hard metric on “fitter”, then the climber probably has the highest VO2Max. Partly because they probably have the higher aerobic fitness (as against the anaerobic fitness of some of the other categories), and partly because a lower bodyweight makes their VO2Max look better.
Thanks that’s an interesting thought.
This is a completely spurious conversation but specialists in any of these fields are unlikely to do well in any of the other domains.
Pure climber beats anyone on a tough gradient, sprinter wins on a flat road race, TT rider wins in a test etc etc
The most interesting thing would be putting them all in a crit. Everyone apart from a climber would stand a chance on a standard flat course as there are different ways to win.
That said a good crit racer at the highest level might struggle to complete a 200km grand tour stage.
tell that to sagan. i figure he would fair pretty well in any crit and he’s shown he can win 200+km grand tour stages and 1 day races. Crits are not about who is the strongest rider, it’s about who can bike handle and manage their power most appropriately in relative comparison to others. You look at Sagan’s wins in both Richmond and Norway and both were races where he managed his ride in the pack and put in the effort when it was required.
Exactly. That’s probably a crit racer’s bigger superpower – power management. Thus, a CR wouldn’t necessarily require the fitness level of the other types of riders. Perhaps eliminate the CR from the list and add CX racer.
Not true. Back in the day I raced with a C1/2 who was a great climber – 5’8, 135lbs – but also won his fair share of crits. Just think about all the post-Tour crits those climber types win. 
It depends on whether you would class Sagan as a crit racer. He’s obviously exceptional.
Likewise whether you view world champs as crits?
My thinking was more around pro conti teams who specialise in shorter circuit races (Tour Series here in the UK). Not many of those guys transition to world tour style multi-stage races.
I laughed