The Cycling Independent Reform Commission (CIRC), set up last year to look into the sport's ugly past, including the Festina affair and Lance Armstrong doping scandal, said an environment existed "where riders can now at least be competitive when riding clean."
"The general view was that doping is either less prevalent today or that the nature of doping practices has changed such that the performance gains are smaller," the CIRC report, published in full by the International Cycling Union (UCI), said.
The CIRC interviewed 174 officials, team managers, doctors and riders during the course of their investigation, which also found that the previous UCI management teams led by Hein Verbruggen and Pat McQuaid showed leniency, especially towards Armstrong, in the fight against doping.
It stated that "the main goal (of a report into allegations that Armstrong used EPO during the 1999 Tour de France) was to ensure that the report reflected UCI's and Lance Armstrong's personal conclusions."
"UCI had no intention of pursuing an independent report. UCI leadership failed to respect the independence of the investigator they commissioned," the report said.
American Armstrong was stripped of his seven Tour de France titles and banned for life from racing in 2012 after a U.S. Anti-Doping investigation (USADA). He later admitted in a television interview using performance-enhancing drugs during his championship run.
DRAMATIC WEIGHT LOSS
The UCI set up the biological passport in 2008, which led to significant progress in the fight against doping, but there were still ways to cheat, the CIRC report finds.
"Despite improvements to the science underlying the ABP (Athlete Biological Passport), it is still possible for riders to micro-dose using EPO without getting caught," the report said.
"The influence on performance is however much less important."
The use of corticoids, and the easy access to them, seems to be cycling's biggest problem, according to two team doctors who were interviewed by CIRC.
They said corticoids were taken to 'lean out' (ie lose weight in order to improve the power to weight ratio), a use facilitated by the fact that TUEs (Therapeutical Use Exemption) are "too easy to obtain".
It led riders to question others to "discuss other rider's top performances, or changes in appearance due to dramatic weight loss, and (being) unable to explain how they were achieved.
"A common response to the Commission, when asked about teams, was that probably 3 or 4 were clean, 3 or 4 were doping, and the rest were a 'don't know'," the report added.
But teams are no longer setting up elaborate doping programmes, the report found.
"There has been a move away from systematic, team organised doping, and that riders now organise their own doping programmes, often with the help of third parties who are primarily based outside the teams," it said.