the sceptic said:Not sure why Froome is so much more obvious.
He did actually show a tiny bit of talent before his magical transformation, which is more than you can say about Wiggo who was literally on the same level as Cavendish wrt future grand tour potential.
It's due to Wiggo being a serial winner at World and Olympic level on the track. The ability to perform consistently when it matters over a number of years is not a common quality but one that is very important in stage races. When Wiggo isn't in "CBA" mode, he very rarely goes AWOL physically or mentally.
I'll grant you that this aspect to Wiggo might actually explain why he succeeded in the Tour when most dopers don't rather than why Wiggo might have won clean!