spalco said:
			
		
	
	
		
		
			Hm, so GW501516 has been around since 2006, AICAR since 2008 or so, and both are potentially really ****ing dangerous, and it's easily detectable, and I'm supposed to believe that's Sky's magic potion that explains why they win stage races? Doesn't add up for me.
		
		
	 
 
Hopefully this example will help:
EPO has been around the professional peloton since the 90s.
The EPO test has been available since 2000.
EPO is rumoured to have 
killed riders, and certainly lead them to wearing heart rate monitors in their sleep to wake them up when their heartrate went too low, so they could get up and do something about it.
None (?) of the USADA people who wrote affidavits ever tested positive for EPO, and yet all confessed to using it, 
years after the fact, as part of the reasoned decision.
EPO had a dramatic effect on the peloton and the performances of the riders using it.
PEDs are rarely used in isolation. ie more than one is used, for different purposes, possibly at different times of the year / training+racing cycle.
The wealthier you are, the more likely you can 
1. employ doctor(s) to help you use PEDs more effectively, from both a response and testing point of view
2. get access to new (versions of) PEDs, leaving the (older) PEDs that now have tests ratified for them, behind
3. wield influence in the rarified atmosphere of cycling's upper echelons about whose profile gets tested and by whom, etc.
These are all points that have been expounded through the recent USADA / LA or BALCO cases, and not much has been provided publicly as indication of proof that anything has changed very much at all.
ETA: looks like GW501516 was banned in 2009 but the test capaciity has only just been announced now, this year.