What's happening to my brake discs?

[Fallout]

The pads may be binding now. I don't think they were before, but now the pads lightly scuff the surface each time you spin the wheel. Enough to stop it after a few revolutions when you spin it off the ground. I know that's not a lot but maybe it's making it worse now. It actually moves the pads slightly in the calliper with a little "click" which is why I wanted to get it sorted out.

Bibio, I'll take your word for it they're fubar ... AGAIN. But if I can sort it to some degree before I replace the discs, that'll stop me going through yet another set. I'll try the fork alignment and replacing the discs on the hub.

[millemille]

Check that the bobbins which connect the carrier to the rotor and allow the rotor to float aren't all gummed up with brake dust and detritus and have seized, meaning that the rotor can no longer float and expand/move as it needs to as it heats up.

Many oem disks are known for this.

A jewellers screwdriver, toothbrush and brake cleaner used to pry the bobbin to one side and then scrubbing and blasting the crap out of the gap will free it up, repeat this for all the bobbins.

[Sid Squid]

Those bikes were notorious for this, we're the replacement discs OE parts? If yes then my advice would be good quality replacements - PFM, Brembo, Grimeca for example.

[Bibio]

the pads are scuffing the disc due to the raised part (peak) of the disc/s, the click you hear are the pads rising and falling in the callipers as they grab the raised part of the disc. pads are loose in the callipers which is perfectly normal.

you could try as others have said and clean the bobbins but i doubt that it will work.

[Fallout]

I cleaned the bobbins in my last set. They could spin and the disc 'floated' pretty well. This new set the bobbins were pretty tight but clean. I took it out today and the issue is pretty minor. I feel like if I can sort out the cause now I might be able to prolong the life of these discs, so gonna try the fork alignment and check the mating surfaces of disc and hub before the next ride. Thanks for the advioce (yes, said in an American 30s gangster accent).

[Dave20046]

I'd bet it's the calipers (are they tokico by any chance?), try a different set (I know you;ve said they were overhauled but the pistons could still be coming out cocked to one side.

[dirtydog]

Reminds me I still have to swap the front discs on the SV. Couple of really loose bobbins on mine, I also got some 2nd hand ones as funds were tight at the time.
Hopefully they last longer than fallouts!

[Sid Squid]

If the pads are flapping about in the calipers something is wrong - it's far from normal.

[embee]

From the description of it being a progressively deteriorating thing, my thoughts would be towards irregular transfer of pad material to the disc surface.

If they were mine, I'd take the discs off and generously rub down the surfaces with something like 80 grit, working diagonally across the braking surface so they end up looking like a spiral pattern. Use a sanding block to keep the surfaces as flat as possible. It'd be worth doing the pads as well, though you do have to be a bit cautious on pads not to get abrasive grit stuck in the surfaces.

The brakes then need to be bedded in thoroughly, progressively increasing the speed and rate of braking, don't be too gentle.

On other bikes, people have "cured" similar issues by using different branded pads, Carbone Lorraine seem to get the nod but others' experiences may differ.

Just my thoughts.

[Littlepeahead]

If it's happened more than once it might be the Missus trying to get rid of you. Or the dog. Have either of them taken out life insurance for you?