The people who race mobility scooters
With a top speed of eight or 10 miles per hour, mobility scooters are not designed with motorsport in mind. However, souped-up models are increasingly being used for racing and record attempts. Why?
The high-speed rider
"I've often said to people if you want to turn heads don't buy a Ferrari, pimp a mobility scooter up," says Colin Furze, who set a record of 71.59mph in a mobility scooter in 2010.
He has "pimped" three mobility scooters so far, by fitting them with motocross bikes engines.
"It's an experience," he says. "These things have been designed to turn around in a shopping aisle so the steering is quite responsive. You have to keep it dead straight."
Mr Furze used to be a plumber but now makes money by posting videos of his creations on YouTube.
One shows him racing an aircraft at an airfield in Lincolnshire - and accelerating faster than it.
He was winning the race until the aircraft took off.
"It was very strange having a plane next to you while you were riding on it," he says. "It was a silly race anyway but it was a good match."
His record was narrowly beaten in Denmark in 2012 and since then two Isle of Man mechanics have built a mobility scooter that can travel at 107.6mph.
He thinks using mobility scooters for record attempts is appealing because everyone is used to seeing them being driven at 4mph in the supermarket.
"When you see them in their normal life they are so slow and not built for speed, so to make something go fast that shouldn't normally go fast is the appeal," he says.
"People like things that move. Anything that moves, people will try and race them and get some kind of competition."
Old ones can also be picked up quite cheaply, he says, or are inherited from grandparents.
"There are all these old ones lying around that people have got," he says. "Why not race them?"
The endurance rider
Steve Tarrant has set endurance records in mobility scooters since being injured while marshalling at the Goodwood Festival of Speed, a heritage vehicle racing event, in 2000.
A car hit him at about 100mph and the driver and another marshal died, but Mr Tarrant narrowly survived, although his right leg was amputated.
He has made two attempts to break the record for the greatest distance covered in 24 hours.
The endurance challenge - which involves pulling a lever and sitting in a chair while continually going around in circles - requires skill and constant concentration.
"I probably adopted the motorsport mentality," says the 54-year-old, who lives in King's Stag in Dorset.
"There were tyre marks where I was effectively skidding around each corner because I was doing it flat out."
His scooter only travels at a maximum of 10mph and he had to allow time for "pit stops" so the battery could be changed.
But on his second record attempt he achieved 190.2 miles (306.1km), exceeding the 170.63 mile (274.60km) record set in California in 2013.
His efforts have not been recognised by Guinness World Records, however, because of a technicality relating to the track, but he raised thousands of pounds for charities.
The banger racers
Banger racing, mobility scooter-style, is known for its low-octane thrills and spills.
Scooters topple over and shopping baskets go flying as competitors repeatedly ram into each other.
"We weren't taking the Mick out of anyone, it was all for fun," says Matthew Watson, who promoted a recent event at Buxton Raceway, in Derbyshire.
"We did try to get people who used them for day-to-day use to come out and have a laugh with us."
He said it went so well he is doing it again on 14 June.
Video footage of the event reveals many of the racers took it seriously, despite their scooters being slower than a child's go-kart.
"We weren't allowed to adapt them," said Mr Watson. "I had one man, he rang me up and said 'I've got one with an engine in'.
"I said 'You can bring it up but you are not in the race'. So he went up and down the straights and entertained the crowd."
The long-distance rider
Former soldier Andy McIntosh says he has "been in some very dark places" since becoming disabled in 2008, due to complications from corrective surgery following an Army injury.
He has a rare vascular condition that means he can only walk very short distances.
"When they turned around and told me this was going to be me for life, I needed something for me to focus on," the 42-year-old says.
He heard about a disabled former Royal Engineer called Simon Angel riding from John o' Groats to Land's End on a mobility scooter.
He decided to do the same, except he wanted to smash the world record of 24 days and nine hours.
"I'm ex-Army and I'm very competitive," he says. "I'm the type of person that if I set my mind to something I'm going to do it."
He plans to set off on 5 May and complete his journey in just 16 days - more than a week quicker than the current record of 24 days and nine hours.
The challenge will raise money for military charities including Poppy Scotland and Erskine.
"They just helped me and my family so much and it's our chance to give something back and to help others," he says.
"This is my way of being able to help other people that are going to face the same."
'People want a challenge'
Helen Dolphin, director of policy and campaigns for the charity Disability Motoring UK, does not have a problem with mobility scooters being raced by people who do not need them.
"I try not to take offence at this sort of thing. There are far more serious things to take offence at," said Ms Dolphin, who lost all four limbs to meningitis when she was 22.
"As long as it's not on the road and it's not harming anybody I tend to take the view live and let live.
"What people do on private property they do on private property. Let's hope they don't end up genuinely needing one for good."
Disabled people have used mobility scooters for records and challenges for about 15 years, according to Tim Ross from supplier TGA Mobility.
He gets about six people each year approaching him for support with their attempts.
"I get a lot more inquiries than I used to," he said.
"The people who have done it with us have been people who wanted a challenge. They may have had some hard times and they want to prove themselves.
"Just because they are disabled they don't want to sit in their house watching Jeremy Kyle."