Controversial Brit artist Damien Hirst has designed the machine for America's seven-time Tour winner to ride into Paris.
Hirst, who had earlier created works with insects, bred the butterflies, which were then killed and their wings glued to the hi-tech bike.
But Sam Glover, of animal rights group PETA, called the stunt 'barbaric'.
"Lance Armstrong is all about life - about not dying and overcoming adversity," the Sun quoted him as saying.
37-year-old Armstrong, is a cancer survivor and has plans to raise cancer charity funds.