The companies making bicycles from wood
The forerunner of the bicycle - the laufmaschine or running machine - bears only a passing resemblance to the pedal-bikes we know today.
Invented in 1817, it had no chain and was powered by the rider pushing his feet along the ground in a walking or running motion.
Even more unusually, its frame was made from wood.
Jump forward to 2017, and a crop of bike makers is turning back the clock - at least in terms of using wood as a core material.
These firms make their bicycles in part, and occasionally wholly, from woods such as ash, oak and walnut.
They are driven by a love of craft and design, the desire to use natural materials, and a passion for cycling itself.
And they have attracted a small but growing base of enthusiastic customers, willing to pay high prices for their lovingly crafted creations.
"People like having something unique, something different," says Chris Connor, the founder of Connor Wood Bicycles.
"They also appreciate the craftsmanship. Not a lot of things are built by hand these days."
The company was born in 2012, after the 48-year-old American decided to combine his long held passions for woodwork and cycling.
All his bikes all have wooden frames; the other parts, such as the gears and wheels, are made from steel, carbon or rubber.
Prices range from $3,500 (£2,600) to $11,000.
Sales have gradually been increasing, but it hasn't been easy, says Mr Connor. That's because of a perception among some cyclists that wooden bikes may break or be unsafe.
In fact, Mr Connor says wood is very durable, which is why it's used to make tool handles, skis, boats, even light aircraft.
It also absorbs vibrations well, making cycling on bumpy roads smoother, less tiring and quieter.
"And of course, these bikes look great," says Mr Connor, who makes his frames made from "strong but flexible" white ash or "eye candy" black walnut.
A recently published book called "The Wooden Bicycle: Around the World" features 111 companies that make bikes from wood or bamboo.
Only one, Splinterbike in the UK, sells 100% wooden models with its bikes featuring wooden gears, chains and wheels.
However, most limit their use of wood to the frame, and occasionally parts such as the handlebars and forks. Other parts will be made from materials typically associated with bikes, such as aluminium.
It is the unique design of wooden bikes, and their bespoke craftsmanship, that underpins their appeal, says Gregor Cuzak.
The Slovenian co-founded Woodster Bikes after meeting woodworker Iztok Mohoric, who had recently designed a bike with a wooden frame.
"I wasn't interested at first, but after I saw it and took a ride, I was immediately convinced," Mr Cuzak says. "People were watching me as if I was driving a wild sports car."
Like other firms in the space, Woodster is targeting customers who appreciate the finer things in life. Its bike frames are made of woods such as beech and bog oak, and prices range from 2,500 euros (£2,190) up to 17,000 euros.
In addition, every customer gets a book with a story about how their individual bike was made.
"We even plant a new tree at the same location where we cut one for your bike," Mr Cuzak adds.
Piet Brandjes, 63, who co-founded Dutch firm Bough Bikes, agrees that wooden bikes "attract attention".
For that reason, firms in the Netherlands such as Novotel and Rabobank have bought Bough Bikes for their guests and employees to use.
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The bikes are also used in a shared bike scheme at Schiphol Airport business park, in Amsterdam, so workers can give them a spin.
Mr Brandjes says all his models have French oak frames, handlebars and front forks. However, customers don't need to worry about them getting wet in the rain.
"The bikes in the shared scheme have been outside for three years and they still look good," he says.
"As long as wet wood dries again, it's fine. You just need to polish it once a season."
Everyone I spoke to reported feeling frustrated by assumptions that wooden bikes were less safe and sturdy than other bikes.
Mr Connor tells me that by using the right woods and construction techniques, his bikes are perfectly durable.
"A strong seasoned wood, laminated to itself in strips with reversing grain directions, bonded with aerospace adhesives is incredibly tough.
"Add in interspersed layers of carbon fibre and Kevlar, like in my bikes, and the strength far exceeds the requirements for making a reasonably lightweight performance bicycle frame."
As for how they function, Mr Brandjes points out that all of his bikes have been tested by TUV Rheinland, a renowned German organisation that certifies products.
However, other obstacles may hinder firms in the space.
For one thing, wooden bikes tend to be heavier than many road bikes. The various models of the three companies I spoke to weigh between 9.9kg and 25kg.
"You can't make them as light as carbon bikes," says Mr Connor, "but I don't think a pound or two more or less matters."
The people who buy them are not competitive riders, he adds.
Another issue is that wooden bikes tend to cost a lot, which may be preventing higher volumes of sales.
American firm Renovo, whose bikes start at $3,995, is probably the number one producer of wooden bikes worldwide. And yet it told the BBC it had only sold 1,000 models since it was founded in 2007.
"If someone manages to create a wooden bike for under 1,000 euros (£914), sales might rise," Mr Cuzak says.
He has only sold 10 bikes since he started in 2015, meaning that he and his partner still have to work on the company in their spare time.
However, Mr Connor runs his business full time, having sold around 65 pieces to date. And Bough Bikes has shifted about 600 bikes since it was founded in 2012.
Summing up what many in the wooden bike industry believe, Mr Cuzak says, "this is not a regular business, but a slow business".
However, he adds: "We've planted the seed and are now waiting for the tree to grow. I believe it will, eventually."