One week after the publication of the Usada report that revealed the gory details of Lance Armstrong's doping, laying to rest any remnants of his sporting credibility, the public persona of the former seven-times Tour de France winner began disintegrating. With damage limitation clearly their goal, Armstrong's long-time backer Nike dropped the Texan, and he almost simultaneously stood down as the chairman of the cancer foundation Livestrong, which he had founded just over a year after his diagnosis for testicular cancer in September 1996.

Armstrong's resignation from Livestrong came in advance of a ball on Friday in his hometown of Austin, Texas, to celebrate the 15th anniversary of the foundation's inception, with thousands expected to attend, including stars such as the actor Robin Williams, a longstanding Armstrong fan. A statement from the charity stated that "to spare the foundation any negative effects as a result of controversy surrounding my cycling career, I will conclude my chairmanship." Armstrong's responsibilities transferred to the vice-chairman Jeff Garvey; he will remain on the Livestrong board.

Following publication of the massive Usada report condemning Armstrong as a serial drug taker – who coerced team mates into blood doping and bullied witnesses who attempted to blow the whistle on him – Nike had stated only a week earlier that they would stand by their most prominent athlete.

This was an abrupt U-turn, citing "seemingly insurmountable evidence that [Armstrong] participated in doping and misled Nike for more than a decade". That brought to an end an association which had lasted since Armstrong's first Tour win in 1999, and at one time seen the US company produce the Tour de France leader's celebrated yellow jersey. The Armstrong sponsorship had spearheaded the company's move into cycling clothing on the back of his Tour successes, and he was said to earn about $7.5m (£4.6m) annually from the connection.

The sponsor added: "It is with great sadness that we have terminated our contract with him. Nike does not condone the use of illegal performance-enhancing drugs in any manner. Nike plans to continue support of the Livestrong initiatives created to unite, inspire and empower people affected by cancer." A spokesman also confirmed Nike will change the name of the Lance Armstrong Fitness Center at its world headquarters in Beaverton, Oregon.

Livestrong, Armstrong and Nike are a closely-knit trio thanks to the sportswear company's production of the yellow silicone Livestrong wristband which was introduced in May 2004. It has sold more than 80 million units, and having been initially launched to raise $25m (£15.4m)for the cancer charity, achieved its target within six months.

It was worn by many of the riders in the 2004 Tour, which was won by Armstrong, and has been seen on the wrists of celebrities as diverse as the actor Matt Damon and various US presidential candidates. Recently, there have been reports of wearers crossing out the "V" to create the motto "LieStrong".

Armstrong retains other sponsorships, some of which pre-date his first Tour de France win in 1999, such as the sportsglasses maker Oakley and the cycle manufacturer Trek. These include Anheuser-Busch InBev's Michelob Ultra beer, and RadioShack Corp – which sponsors the RadioShack-Nissan-Trek squad – as well as smaller companies such FRS Co and Honey Stinger, which make energy and nutrition products.

As well as possible moves by these sponsors, Armstrong faces other issues in coming weeks if the International Cycling Union ratifies the Usada decision to strip him of his Tour titles. The Sunday Times has said it will look to recover around £1m in costs arising from the libel case brought by Armstrong after the paper alleged he had used banned drugs in 2004; the Texan could also face a counter suit from promotions company SCA which insured bonuses for four of his wins to the tune of $12m (£7.4m).