I race road. I race at E1 level, which is 1 level below Pro Tour. The speeds in E1 are similar to that of Pro, but the 'Tours' are way shorter, and in comparison to Pro riding, we don't go in as hard.
The main thing I can say, from my experience racing, and seeing how my own body reacts to the stresses of going in so hard, is this...
-A top level guy who is not doping, could match the speed and power of one of these world class pro tour guys, in a single day event, but he would be utterly wrecked at the end of it and would need a good week to recover.
-Pro tours are 3 weeks long. There is no FUCKING WAY they are going in that hard, for that long, and with only 2 rest days, without chemical assistance. I don't care how much they train, or how elite they are, the human body simply can not take that much abuse, both in terms of pure physical stress to the muscles, and also throwing that much water and food through your system day in day out, without blowing up after at most, 10 days. It just can not be done.
Whether they are all on straight EPO or not, I think is doubtful. Probably not nowadays, as that is too detectable, and obvious. I think what is happening nowadays, is they are doing way more sophisticated stuff like micro-dosing the training, then switching drugs around, etc., to achieve the same end. The doping process has basically become more refined.
So yeah, of course they are doping, but not in the same way as when it was full on EPO jacking.