Pantani's normal stage bike in 1998 weighed 15.3 lbs/ 6.93kg with cages and pedals, his climbing bike weighed less certainly.Pantani had a bike 0,7 kilos heavier, less aerodinamic, and surely other factors make today bikes better. Climb a climb as Plateau, with a bag with 1,5 bottles and for sure you will take more time.
No, just the performance itself is not for sure a doping performance, even when Pantani was a very doper rider, but it is an amazing performance to study and to make us questions...and that is not bad..in other sport nobody make questions and I see much more amazing things.
What is was imposisble is that in those years Festina was proven dopers and to think than the rest of people who beated Festina riders where all clean. It was clear and lot of deluded people didnt realize, the same today lot of deluded people dont relized things changed.
Lance Armstrong had a climbing bike back then that was sub 6.8kg, it's the one with the downtube shifter for the FD. UCI weight limit wasn't enforced until the 00s.