Backpackers Hostels in Tokyo?

In considering a trip and a place to stay, is Tokyo well covered with backpackers/YHAs etc...as I find these a preferable experience to hotels, as well as cheaper.
What about cycling in Japan as way to get around?
Is it ok, Japanese drivers reasonably competent and considerate to cyclists? Do many roads have cycle lane?
Are bikes allowed to be carried onto Japanese trains?
t/y

Maybe this will give you first information:
http://www.japan-guide.com/e/e2028.html
But do more search in this wonderful japan-guide

Good Lord! you must be one of the few people unaware that most Japanese use bicycles at one time or the other, even in Tokyo!
there are huge bike parkings near every railway and subway station, near pedestrian streets etc. even fancy apartment buildings have bike parkings. Car drivers are considerate because chances are that they use a bike to go from home to a rail or subway station when going to work. However most residential streets don't have sidewalks, much less bike lanes. it is a bit messy but it works. On wide avenues bikes ride on the sidewalks. Just follow an old lady on a bike and you will be safe!
there are many blogs and even U-TUBE videos on biking in Japan. one last thing: bikes must be registered with the police. if you take your own bike with you bettter take a document showing that you own it.

no, I knew I was taking a risk of sounding wet behind the ears posting this, but I didnt know Japanese were major cyclists, I did wonder, I associated massed cycling with China, not Japan. I think I thought the Japanese were highly automated and car-loving people also.
Even though it makes sense to use bicycle in any small crowded country..but of course Japan is famous for its public transport,and its cars, never hear about bikes, except motorbikes, so I wasnt sure.

Bikes must be registered with police?

Do you need a license plate?

I wasnt sure whether to take on with me, as you have to reckon the cost of flying it etc vs cost of buying one there and abandoning it or giving it away when you leave.
I own 6-7 bikes currently, I couldnt provide any 'papers' for any of them I buy them at garage sales, Sunday markets, or some I simply find dumped needing A small repair.

Why the police hassle over bikes?

average bikes are cheap but are stolen which is a hassle for the commuter trying to go back home after a long day and a ride in a crowded train. hence the requirement to register w/ local police. They do spot checks and it seems that they check younger foreigners on bikes more carefully than a local old timer. Also if you park illegally your bike will be consficated and your registration number allows the police to find you and fine you.
check www.japan-guide.com/e/e2210.html for everything you need to know about bikes in Japan.

I cant believe they do spot ownership checks on bikes...or have bicycle no-standing zones and tow away the bikes!!!!!????
These things I have never heard of anywhere, let alone here.The only risk of police attention to any cyclist is riding no helmet, riding no light after dark, or blatantly running a red light straight in front of a patrol car. Even then your odds are still pretty good of being ignored.

Is there so little crime in Japan, or they have so many police, they can put this much scrutiny into bicycles?

In Netherlands there is a bike crime problem, the govt issued thousands of bikes to people for free, yours gets stolen, you just take someone elses.
Much more laid back.