Johannesburg, South Africa (CNN) -- As Nelson Mandela turns 93, one group of South Africans has been getting revved up in tribute to his legacy.
A multiracial, multilingual group of South Africans have ridden their motorbikes across the country's highways and byways for the last week, doing good along the way.
Over the past week the road warriors have been lending a hand at seven rural community projects in forgotten little towns along a 2,200 kilometer route. It's part of the Bikers for Mandela Day initiative -- their gift to Nelson Mandela for his birthday.
In the small town of Harrismith the bikers stopped off to paint a small orphanage, adding a little color and a little hope to the children's lives.
"For Madiba (Mandela), it demonstrates to him that people are passionate about his legacy," says Zelda la Grange, Mandela's personal assistant, who rode with the bikers.
Since 2009, the former South African president's birthday has been designated "Nelson Mandela International Day."
But July 18 isn't a national holiday: Supported by the U.N., it's a day of public service, on which people are encouraged to spend at least 67 minutes doing some kind of community service in honor of the 67 years Mandela spent fighting for social justice.
Mandela is now too frail for public appearances, battling the health problems that come with old age. But many in South Africa want to remind him, and others, that his sacrifices and his extraordinary life journey are not forgotten.
"It's changed my views when it comes to helping people," said another of the bikers. "It is a selfless act, it's not something that you need to be pushed (to do) by other people ... I need to think for myself, 'What can I do for others?' Especially things they can't do for themselves."
Last year the riders were joined by Hollywood star Morgan Freeman, and this year their numbers include South African celebrities such as radio presenter DJ Fresh.
But the point, they say, is not about celebrities doing good deeds -- it's about reminding ordinary people that Mandela's most enduring legacy is to give a little of yourself for the greater good.