LeMond posted an open letter on his Facebook page Wednesday night that asked those who care about cycling to join him in telling International Cycling Union President Pat McQuaid and honorary president Hein Verbruggen to step down.
LeMond's letter came after the UCI stripped Armstrong of his seven Tour de France titles and banned him for life on Monday for his involvement in what a U.S. Anti-Doping Agency report described as a massive doping program.
Verbruggen led world cycling from 1991-2005, the era when Armstrong won his titles, and retains a seat on the UCI management board. He is still perceived in the sport as a mentor to McQuaid, who succeeded him.
LeMond, the Tour winner in 1986, '89 and '90, said the problem for cycling is not drugs but corruption.
The only American remaining on the 99-year Tour list of champions told McQuaid: "Pat in my opinion you and Hein are the corrupt part of the sport."
McQuaid, an Irishman whose second term as UCI president expires in September, said Monday he had no intention of resigning over the systematic drug scandals that have ruined the sport's credibility.
"I believe that there are many, maybe most that work at the UCI that are dedicated to cycling, they do it out of the love of the sport, but you and your buddy Hein have destroyed the sport," LeMond said.
"You know ... well what has been going on in cycling, and if you want to deny it, then even more reasons why those who love cycling need to demand that you resign."
Verbruggen declined to respond to LeMond's comments when contacted by The Associated Press.
LeMond won support from Pedro Delgado, the 1988 Tour winner, who used his Twitter account to post a headline that said corruption was a bigger problem for cycling than drugs.
"Totally agree with my ex-rival Lemond," Delgado wrote.
The UCI and its leaders have reacted to previous corruption accusations by filing defamation suits against Floyd Landis, who was stripped of the 2006 Tour title for doping and was a key witness in the USADA case, and Paul Kimmage, an Irish journalist and Tour rider in LeMond's era.
McQuaid has refused to back down from suing Kimmage over accusations that cycling's leaders protected Armstrong. The case is scheduled to be heard in Vevey, Switzerland, on Dec. 12.
"This is about a journalist who accused me, and my predecessor and the UCI of being corrupt. It's a straightforward defamation case," McQuaid said Monday at a news conference called to confirm sanctions against Armstrong.
McQuaid, Verbruggen and the UCI announced this month they had won a similar defamation case against Landis — and damages of 10,000 Swiss francs ($10,667) each — after the former Armstrong teammate made similar allegations. Landis was not served with papers in the case and it is unclear if the judgment carries any weight outside Switzerland.
LeMond is backing Kimmage's legal battle, which has become a lightning rod of cycling fans' anger at how the sport's image is being shattered. A defence fund created by two cycling news websites has raised more than $73,000 to pay Kimmage's legal fees.
"I would encourage anyone that loves cycling to donate and support Paul in his fight against Pat and Hein and the UCI," LeMond wrote. "I donated money for Paul's defence, and I am willing to donate a lot more, but I would like to use it to lobby for dramatic change in cycling.
"The sport does not need Pat McQuaid or Hein Verbruggen."