cody_57 said:
There are more exceptions to this rule: Pantani won 2 in '98, Big Mig did doubles in '92 and '93. Are these riders part of the modern era?
Induráin's Giros show us the evolution of the Giro becoming too hard and top riders' form becoming too targeted for anyone to win both no matter how good
:
His first year at the Giro, he won both GTs comfortably.
The second year, he won both, but was not the strongest at the Giro, winning it due to a course with few mountains and many time trials, and ran out of gas at the Tour, suffering to hang onto Rominger so much that by the end he was thrashed by Rominger in the final TT. He skipped the extremely lucrative post-tour criteriums because he was too dead to even start in them.
The next year, he did the Giro as a warmup, and the year after that he skipped it entirely
As for Pantani, he won the Tour due to a random off-day by Ullrich and the Giro due to Festina screwing up Zülle's doping programme (explained in detail in Willy Voet's book "A manquer la chaine"). Zülle was by far the stronger rider at that Giro.
Under normal circumstances, Pantani wouldn't have won either. That he won both was tremendous talent, yes, but also tremendous luck. Especially with the case that Fanini recounts with switching his urine with a teammates' to avoid testing positive
In the past 15 or so years it's no longer possible to win both unless tremendously rare circumstances conspire.
EDIT: To make it clear, I'm talking about winning the Tour + another GT in the same season. Winning the Giro and the Vuelta is feasible, as there is enough time to lose form and then rebuild it in time to reach your top level again.