The village announcer dipped his razor in a cup of cola nuts and water and briskly shaved the baby’s forehead. Then he carried her across the compound to present her to a circle of elders gathered under a mango tree. They nodded their approval, as if for a good bottle of wine. The baby was returned to her mother. The announcer, in a purple robe, stayed with the elders to conduct the naming. He made a short oration, stopped to collect a fistful of donations and revealed the baby’s name – Masiranding, after her grandmother.

It was a modest ceremony even by the straitened standards of western Gambia. But it was remarkable for the simple fact that Masiranding was being named, not buried. A week earlier, at 4am on November 6, her mother had woken up bleeding. She called for her husband, who was asleep in another room. He ran in, saw the blood and got ready to take her to the nearest clinic. A taxi would have cost at least £2.50 that he did not have. Instead, Fabakary Darboe lifted his wife into a sidecar bolted to a silver-grey Yamaha AG200 motorbike. It started first time and got them to the town of Banjulding by 4.30am. He was told at the clinic that his wife, Fatou Boya, would die without an infusion of fresh blood. But the clinic had none, so Fabakary put her back in the sidecar and rode on through the darkness to the capital, Banjul, and the biggest hospital in the Gambia. They reached it at 7am. A Cuban doctor gave Fatou antibiotics and the blood she needed. At 10am, with no further complications, Masiranding was born.

The contraption that saved her life is not the world’s most sophisticated ambulance, but it works. The patient can lie strapped to a stretcher on top of the sidecar if it’s too uncomfortable for her to sit. There is a mini-boot for personal effects and medical supplies, and a pillion seat on the bike itself for a relative or nurse. In this case, in the village of Mandinari, there is also a plaque the size of a beer mat that reads: “Funded by Hitchin Rotary Club”.

Thereby hangs a tale of big-hearted Hertfordshire philanthropy, and Mandinari is grateful for it. But the story of Masiranding’s and her mother’s survival is also about the organisation that designed this machine, delivered it, trained its riders and now keeps it fuelled and maintained to be ready day or night. That organisation is called Riders for Health. It’s based in Daventry in Northamptonshire and so far has been sustained to the tune of £1 million a year by the generosity of people better known for risking lives than saving them – motorcycle racers and their fans. Most of them are based in Britain, where their efforts are co-ordinated by a former bike racer, Andrea Coleman, who lost her first husband to the sport and is one of Riders’ founders. But the maintenance programmes that the charity operates in three African countries are, crucially, staffed entirely by local mechanics and administrators.

By training health workers to maintain their own motorcycles, these programmes can be vastly more effective than if the charity operators had to tighten every brake cable themselves. By charging local governments and NGOs for their services, albeit on a non-profit basis, they operate outside the cycle of aid and dependence that hobbles so much charitable work in Africa. And by strengthening the weakest link in any African development project – getting from A to B along the world’s worst roads – they are making a measurable difference where generations of good intentions have foundered. For these reasons and many more, Riders for Health is the international charity chosen for this year’s Times Christmas Appeal.

One morning last month, on a rutted dirt track near the north bank of the River Gambia, I had a go on one of their machines. It was a throaty beast with a single 400cc cylinder and a clutch like a moody bus driver, ready to stall or lurch at the horizon without warning. Sitting still on it in a full-face helmet and protective jacket, I felt like I was cooking. But moving, and knowing that no sinkhole or fallen baobab tree could stop me, felt fabulous. Small wonder the people Riders train talk unselfconsciously about empowerment – or that Ewan McGregor is one of their staunchest supporters.

Riders has been operating in the Gambia for five years, to nigh-on miraculous effect. Their main client is the health ministry, whose entire fleet of 108 4x4s and motorbikes they are contracted to keep on the road. For good measure, they operate a zero-breakdown policy. With just one major paved road outside Banjul, and 60 per cent of all healthcare delivered to patients rather than vice versa, this is like operating a scheduled service to the moon. Yet it seems to work. It does so with a system of preventive maintenance that would shame any British rail operator. Spark plugs are changed before they stop sparking. Cylinders are re-bored before they seize up. Money permitting, vehicles are replaced before they break down unexpectedly, and no health worker climbs onto his or her motorbike without giving it a once-over worthy of an airline pilot. This means ambulances work, travelling clinics travel, and every community health nurse with “outreach” responsibilities for rural villages has a sturdy Japanese motorbike to take them there.

Why did no one think of this before? The question goes to the heart of the multibillion-dollar debate over whether Africa’s healthcare crisis will be solved by high science or low-tech. It’s also a question that is apt to ambush you in places like Jahangka, a long way upriver from Mandinari. Apart from the mobile-phone mast rising surreally from among its thatched mud huts, it might as well be in another century. The average extended family here is lucky to earn a pound a day from the sale of peanuts, the local “cash” crop. Not one of the 3,000 people owns a car. The nearest doctor is a four-hour walk away, so the best measure of wealth is access to a cart pulled by a horse rather than a donkey. Jahangkans are now the proud custodians of a second sidecar ambulance from Riders for Health (they’re called uhurus, from the Swahili for “freedom”). But Hatou Boye remembers life before it came. He does not remember willingly; it’s more a case of not being able to forget.

Two years ago, in the first month after Ramadan, Hatou was another young husband answering a 4am cry from his young wife, who was about to have a baby. Her name was Rohey Ceesay. “She told me she was feeling pain,” he says, “so I came out to look for a horse cart. There was none in the compound, but I remembered a friend who had one in the fields. I took my bike and went to borrow it.” It was a quick ride even in the dark – about 2km. But by the time he came back, Rohey was too exhausted to sit, so she lay on the cart, held there by Hatou’s stepmother as he concentrated on controlling the horse along the road to Bansang hospital. They were nearly there when the stepmother told him to turn round. “I assumed my wife was about to deliver,” Hatou says. “But when we reached the mosque in Jahangka my stepmother asked me to tell the elders she had died.” Her child died, too; they were buried as one. Hatou used to have pictures of Rohey, and a set of bowls he gave her at their wedding, but his brother destroyed them to stop him crying over them. He now has a second wife and a healthy 13-month-old girl, but looks as if he has never smiled and never will.

This is not Darfur. The Gambia is reasonably fertile and at peace with its neighbours and itself. It has no oil, but neither does it have the curse of oil dependency. What it has, like so much of West Africa, is stubborn, abject poverty and lethal, endemic malaria. Its national malaria-prevention programme is comprehensive, but the disease can still kill a child in a day, especially in the rainy season.

Ancha had borrowed a donkey cart and travelled since dawn to attend a free outreach clinic at Njoben, near the Senegalese border. She had brought her children with her. Mariama, at nine months, was vomiting whenever she tried to eat. Kebba, three years old, had been nursing a fever every night for a month. Luckily for all of them, a department of health Toyota Hilux pick-up also made the journey that morning. It brought: three nurses, a public health officer, hundreds of one-use plastic syringes, 120 vials of injectable chloroquine, five 300ml bottles of soluble chloroquine, 160 doses of oral polio vaccine and 460 immunisations against hepatitis B, diptheria, whooping cough, tetanus, tuberculosis, measles and yellow fever. At least 200 women and children were waiting for it. Ancha was at the back. She came from the wrong side of the Senegalese border, so had no automatic right to Gambian help. But one of the Riders staff who’d brought us to the village recognised her. He ensured her children were treated, and this may have saved their lives. But the real marvel that day was the one that brought the Hilux over the 19 axle-bending kilometres from Bansang.

It all started in 1988, when Randy Mamola, a charismatic American MotoGP racer with a bad-boy reputation, went to Somalia with Save the Children to see how healthcare was delivered there. Or wasn’t; on the day he was supposed to see a rural immunisation programme in action, his four-wheel drive broke down. He and another motorcycle enthusiast on the trip, journalist Barry Coleman (Andrea’s husband and co-founder of Riders), were dismayed by the sight of health ministry motorbikes abandoned and beyond repair weeks after delivery to Mogadishu, and were unimpressed by the standard explanation – “This is Africa.”