Hub/drum brake - help!

[swee'pea99]

I don't even know what to call it, but it looks like this:

(It's the black doughnut thing, not the hub, which is a dynamo.) It's binding - not solid or anything, but it's a continual scraping drag, which doesn't let up even when the cable tension is slackened off to nothing - and I really can't see how to go about trying to sort it, never having worked on anything like this.

Any hints & tips much appreciated. (Including 'don't bother - it's a major faff and bound to be more trouble than it's worth'.)

It's an old clunker my daughter found abandoned in the park - Chinese, and anything but high end - but it's quite useful to her 'cos she can leave it chained up at the tube station when she goes to work. It's usable, so I'm not into any major overhauls, but if there's a likely solution or two that might work, I'm all ears.

 

[twentysix by twentyfive]

Could there be a spring not springing the pads away after a braking action? Or the bits that pivot have sort of seized a bit? Can't really see much in that pic tho'. Any identifying marks/logos that you could Google?

 

[classic33]

Water ingress at the brake arm that has caused a slight rust to form, binding the brakes

 

[swee'pea99]

I'm pretty much certain that that's exactly what has happened: water has got in and corrosion is preventing something from pivoting back where it should.

Question is if I try to take it apart will I suddenly find myself with bits springing off all over the kitchen? I don't even know if I should disconnect the unit from the frame mounting post and take it off with the wheel, or try to take the wheel off independently. Perhaps wost of all there are no identifying numbers or words that could be googled.

I'm used to being able to work on bikes, but I've just never seen a unit like this. Hmmm.

Thanks anyway - all thoughts appreciated.

 

[Nigelnightmare]

It shouldn't spring apart when you strip it.
If it does, that's your problem/fault found.
Then you'll have fun trying to figure out how it goes together again.

As others have said it's probably corroded & needing lubing.
Don't forget the cable & lever will need lubing.

P.S.
I don't know what make/model it is but knowing the Chinese it will be something weird & wonderful.
Have fun and take plenty of photo's as you dismantle it. (Mobile phones are wonderful for that).

Good luck & let us know how it goes (with lots of pictures).

 

[classic33]

It'll look something like this inside,

Anything that pivots will be on a pivot point, with the spring(s) used to pull the shoes back in, having tight loops/hooks to prevent them falling off.

Picture is to give an idea of what you can expect to see inside, not the one in question.

Undo the cable, and try turning the brake arm fully.