In this era of blinged-up, electronic-geared, ultralight carbon fibre bicycles that can cost as much as a car, it is ironic that the latest trend in the two-wheeled world is actually a case of less is more. We're talking a lot less: typically a metal frame, two wheels, one gear and, often, no brakes.
A fixed-gear bicycle, or "fixie", is as basic as a bike gets. It is so named because, unlike a typical bicycle, it doesn't have a freewheel - meaning you can't just stop pedalling and coast along using forward momentum. On a fixie, the cog is directly bolted to the rear wheel's hub, so if the wheel is moving, the pedals are, too. To stop - if the bike has no brakes - pedal backwards.
For Jason Dembski, 31, an architectural designer who took up fixed-gear riding in 2009 when he moved to Hong Kong, a fixie is the "purest form a bicycle can take".
"Clean and simple - no brakes, no gears, no cables, just the bare essentials," says the native of Columbus, Ohio, in the US. "Beautiful."
There is a small but growing fixed-gear culture in Hong Kong, according to Brian Fu Hau-chun, 44, co-owner of Rodafixa Fixed Gear Boutique in Kwun Tong and the pioneer of fixed-gear bikes in Hong Kong. When he first opened shop - a tiny 300-square-foot space in Kau U Fong in Central - in January 2009, he was selling about one bike every two weeks. These days, he sells about 10 bikes a month.
At the same time, customers are now willing to shell out more for their prized steed: Fu first imported Taiwanese-made bikes costing about HK$3,000 each, but now he stocks a range of bikes that can cost up to HK$18,000.
"Fixed gear in Hong Kong is getting more popular. Sales have gone up about 20 per cent in the past year," says Brian Kwan, 26, founder of Bicycle Pit, which has two shops, in Jordan and Tsuen Wan.
Kwan first got into fixies seven years ago while living in London; he had been riding geared bikes for five years before that. "I feel more attached to the bike when I'm on a fixed gear, and the minimalist appearance looks amazing," he says.
Indeed aesthetics - not only how the bike looks, but also what it says about its owner - are arguably what has made fixies popular, particularly among young urbanites. Adopted by a band of bicycle couriers in New York City and San Francisco in the 1970s, fixed-gear bikes, Fu says, are really just track bikes ridden on the street instead of in a velodrome.
Track cycling has been popular since 1870 and was included in the inaugural Olympic Games. Bicycles were all fixies until the late 1890s when the freewheel was invented.
But in the past few years, the marrying of the fixed-gear bike into pop culture and fashion has elevated the steed to hip status. Actor Joseph Gordon-Levitt straddled one in the recent Hollywood blockbuster Premium Rush, where he portrayed a bicycle courier who gets mixed up in a criminal plot in New York City. Last month, fashion chain H&M announced a collaboration with East London's Brick Lane Bikes, Britain's first fixed-gear bike store, on a new men's collection to launch in March worldwide.
Closer to home, Shanghai Tang worked with Dutch bicycle maker Colossi Cycling on a limited-edition fixed-gear bicycle. Fu's local fixed-gear collective, Flwrider, worked with Lee Jeans in 2011 to showcase a new city cycling clothing line. This weekend, fashion brand agnès b. presents the first Bicycle Film Festival bicyclefilmfestival.com  in Hong Kong, starting on Friday at the Arts Centre in Wan Chai.
But beyond a fashion statement, riding a fixed-gear bike can be a great workout. Professional cycling coach Chris Carmichael, who has worked with Lance Armstrong, incorporates fixed-gear work in his training programmes.
Carmichael says riding a fixie provides much more aerobic benefit than geared-bike riding because the legs are constantly in motion. He says that 90 minutes to two hours of fixed-gear riding is equivalent to about four hours of regular riding.
Joe Friel, a renowned endurance sports coach and author, prescribes fixed-gear riding to improve the efficiency and smoothness of the pedalling stroke. Most people waste energy at two dead spots of the pedal rotation, the six and 12 o'clock positions. The constant pedalling motion of fixed-gear riding can help overcome that.
Having only one gear also builds leg strength and power, because when you a hit a hill, you can't shift down to an easier gear. You've just got to work harder. "Your gears are your legs," says Eric Lee Chi-wai, 44, co-owner of Rodafixa.
Kwan, who cycles up to four times a week, says: "I have become stronger, both physically and mentally, since taking up fixed-gear riding."
Dembski, who mainly commutes by bike, says cycling has helped him quit smoking. The experience of fixed-gear riding is also special. "You feel much more connected [to a fixed-gear bicycle] than you do to a normal bicycle," he says. "Depending on how you look at it, the bicycle becomes an extension of you, or you a part of it."
The simplicity of a fixed-gear bike means it is usually more affordable and much easier to maintain than a regular bike. Lee recommends a budget of about HK$5,000 for a "reasonable bike".
While it may be cool to have no brakes and pull off skid stops, it is illegal to ride without any brakes in Hong Kong, according to former pro cyclist Kenji Leung Chi-yin. "Riders must install a brake on the front to ensure their own safety and also of pedestrians," says Leung, a cycling coach with ZERO1 training group. "And always wear a helmet when you ride."
Pick a gearing that suits your level of fitness and the terrain you'll be riding on. It should be just heavy enough so that you're not spinning like crazy, but also find it easy for starting off from a traffic light and maintaining control going downhill. Having an unsuitable gearing could put pressure on the knees and cause injuries. The average rider will have a 17-tooth cog at the back and a 47-tooth chain ring.
Try to get your first few rides in an area with little traffic and flat terrain to allow yourself to get acquainted with the bike. If you do forget and coast, you'll be immediately jolted from your seat. "Riders should make sure their skill level is sufficient to handle the bike," says Leung.
Is fixed gear just a fad? Lee doesn't think so. "It's never going to be mainstream, but it won't go away. It'll stay as a street culture, like skateboarding."
"With the sport of cycling gaining more attention in Hong Kong," Leung adds, "I believe there will be an increasing number of fixie riders as well."
If the late French bicycle racer and Tour de France founder Henri Desgrange had his way, all cyclists aged 45 and under would be riding a fixie. As he once said: "I still feel that variable gears are only for people over 45. Isn't it better to triumph by the strength of your muscles than by the artifice of a derailleur? We are getting soft ... As for me, give me a fixed gear!"