This is one type of wheel lock that Japanese bikes use. This used some kind of a bolt that would lock into position to stop the wheel from turning if the key wasn't inserted into the lock. It doesn't prevent someone picking up a bike and going away with it, but it does prevent people from getting on the bike and riding away on it.
However, the most common type of wheel lock was a circular one bolted or soldered on the frame, like these ones:
|This one is actually a battery-assisted bike, note the place for the battery|
The Japanese rarely lock their bikes to anything, they use wheel locks exclusively most of the time. Supporting this is that:
1- Every bike in Japan MUST be registered with the police. Store owners will help you do it when you buy a new one, and you must fill in papers to transfer property of the bike on the registry if you sell your bike to someone else or if you buy an used bike.
2- These bikes are mostly viewed as disposable. They are sold at affordable prices and come fully-equipped, so they don't need to be modified and customized to be used.
|If you can't read Japanese numerals, these are 155$, 155$, 155$, 155$, 190$ and 195$, from left to right|
|Divide by 100 to convert yen to dollars, the cheapest one here is 92,50$ (generally tax included in prices)|
Bike parking in JapanAs mentioned in passing, the Japanese largely do not use racks to park their bikes. They park them with wheel locks only most of the time, on their stands. They generally leave them on sidewalks or on the side of the street.
Click for bigger pictures.
I've also seen over-under racks for bicycles around tall residential blocks:
That being said, the haphazardly parked bikes in Japan have become a bit of an annoyance, so there are attempts at providing spaces where bikes can be parked. Sometimes, it's just an area where it's indicated that bike parking is provided, but they have started providing certain bike parking facilities.
The first one is in front of a supermarket in Tokyo, there are secure, self-locking bike racks there, that are free for up to 2 hours, then costing 100 yen (1$) for every 2 hours above that. The second one is also in Tokyo, has surveillance cameras and costs 100 yen (1$) per 5 hours, I think.
I've also seen sometimes outright massive parking facilities around train stations... park-and-rides that even urbanists can love. Like this one in Sapporo, which also included a section for rental bikes:
I also snapped this one while on a train on the Tokaido line:
But this one in Chigasaki was the most amazing by far, it made my jaw drop when I saw it.
3 stories (4 including the ground floor) of bike parking, at 2 minutes walking distance from the station, with a security guard in a booth.
Okay, so these are just my quick observations. I personally like the Japanese city bikes a lot and wish I could get them here. Most cheap bikes in Canada are pre-assembled mountain bikes rather than utility bikes, which require add-ons like stands and racks that significantly increase the cost and are often assembled by semi-competent Canadian Tire staff. And most bikes in independent bike stores start at 300$, if you're lucky. I'd also be all for wheel locks and a mandatory registry system to deter crime and would like these secure self-locking racks.