Why do so many bikes end up underwater? The reasons can be weird and varied

When you glance into a waterway, you probably expect aquatic life and the occasional piece of trash. But the reality in many urban metropolises is that lurking beneath the surface of any waterway could be an astounding number of... bicycles.

It's a strange social phenomenon that has forced bike sharing companies to fish out thousands of their rental bikes from rivers in Southern China; and a rental company simply stopped business in Rome because too many of its bicycles were thrown into the Tiber.

In Amsterdam, 15,000 bikes are pulled from canals each year — a number that has actually improved over past years.

Why have so many of these wheeled vessels met a watery grave? And what happens to a bike once it has changed terrains?

Jody Rosen is a contributing writer for the New York Times Magazine and the author of Two Wheels Good: The History and Mystery of the Bicycle. He joined All Things Considered to shed light on this maritime mystery.

This interview has been edited for length and clarity.

Interview highlights

On how widespread this trend is around the world

This is a phenomenon that kind of came to my attention first because I started to see news items from various places. You know, a Citi Bike here in New York City where I live turned up at a docking station, kind of blistered with oysters and barnacles. I started Googling around online and noticed that this was a very widespread phenomenon on at least three continents. So it's definitely a widespread problem, but the extent of the problem, I think, is sort of by definition unknown because after all, it's hidden. I mean, there are bicycles that are literally covered by the waterways of the world. So it's not something where we can ever have definitive or reliable statistics kind of by definition.

On the existing documentation of this online

When you see the bicycle go in there and slip below the surface of the water, there's just a certain satisfaction, a certain free zone in that. And I say that not because I've done it myself, mind you. This is a practice which is documented online, for instance, on YouTube quite comprehensively. So there's lots of videos that you can see where people are tossing bikes into water and taking videos of it for fun and sport.

So that is definitely a factor. But there's all kinds of other types of vandalism that surround this, which I think are interesting. If we go back to the city of Amsterdam, where there are so many bikes, it's really one of the world's leading bicycle cities. And there are so many canals. It's sort of an ideal environment for the dunking or drowning of bicycles. And it has been historically such a big problem that there is this municipal core of what they call "bicycle fishermen" there that the city employs to dredge the bicycles out of the canal.

On the role of bike share services in the increase of this

That's what I think is behind the current widespread phenomenon. The fact that these bike programs are proliferating across the world, which I think we can say is a good thing — we need more bicycles in the city — but there are simply more of them around. And in fact, you can imagine that people feel a little bit more impunity, that a potential bicycle drowner would feel less guilt attached to tossing a bike in the water if it's a share bike that has a bank or some sort of corporate sponsor's logo on the mudguard as opposed to, you know, some individual joe-schmoe's bike.

There may be what you might call a political dimension to this. We're seeing a kind of increasingly heated debate over what kinds of vehicles belong on the streets of cities. Motorists are reacting to the increased numbers of bicycles on the streets, sometimes with great annoyance and and sometimes with actual violence. So it may be that at least these drowned bikes, these trashed and vandalized bikes reflect a kind of ongoing battle for the right to the roadways.

In China, we've also had instances of people stating explicitly that the reason that they threw bikes into the water was because the bicycles compromise their privacy. These shared bike programs really keep track of the riders who rent them using apps on their mobile phone. And so this is a kind of an ironic thing because at one time in the 19th century, the bicycle was viewed as really an emancipatory machine, a vehicle of liberation, that gave people a new kind of personal mobility, a new kind of freedom they'd never experienced before. Well, now there are bicycles that kind of spy on their riders. So there may be complicated motivations and politics entering into this

On what happens to the bikes when they are recovered

This is another mystery. And we know that in certain places, for instance, in Amsterdam, they are recycled. There's a program there recycling them. And one of the things that I think is funny about the Amsterdam example is the officials there attribute this phenomenon in part to drunkenness. You know, people who have maybe had a little bit too much to drink, maybe they're walking on their way home after a long night in the bar, they might see a bike and say, "What the heck?" they're feeling a little jolly and they toss it in.

Well, many of those bikes, as it turns out, are recycled into various types of food packaging, including the metal that's used in beer cans. So it could be that there's a kind of ecosystem at work where someone, a drunken person, tosses a bicycle into the water, that bicycle is eventually extracted by the bicycle fishing boat, it's recycled into a beer can, and another drunken person comes along, drinks that too much of that beer, tosses another bike into the water, and around we go.

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