Just had a good go at my bobbins - they were well seized up. Used the recommended nut and bolt through the centre technique but used an electric screwdriver to spin the bolt and bobbin, having sprayed with Cillit Bang to loosen the muck. Took quite a while and lots of spinning and spraying to get them all free - let's hope it makes a difference to the brakes...
It will give the disc back a little flexibility so that it will align centrally in between the pads. Braking should be a lot smoother and progressive. Andy
What is the ideal degree of looseness? I went for being able to hear them clicking when you move them.
My experience is fully floating race discs on the 853 which rattle, the 1200s Multistrada which has only a very small amount of movement to the 1098R which you can flex with finger pressure. I prefer the feel of the 1098R but the unless your discs are "fully floating" you should not be able to rattle them from side to side. Andy
Thanks Andy. Are you referring to the discs or the bobbins? I was referring to the bobbins. The 1098 is probably closest to the 999 but I don't have radial calipers. I have freed them to the point where you can slide them freely enough that they will click audibly but that's fore and aft, not lateral movement.
Yes, sorry my ability to describe something is somewhat lacking. The bobbin allows a certain movement of the disc. The fully floating disc is clearly a clearance fit and the 1098 is just not an interference fit. I find the bobbin has a little play in it against the spring washer behind it. Andy
M5x20 bolt plus a plain nut. Put the bolt through the centre of the bobbin and thread the nut on the back hand tight. Using a ratchet or electric screw driver/drill, spin the bobbin up to free the corrosion. So long as you are meticulous cleaning the disc afterwards, some folks use a spray of WD40 or brake cleaner to start the process. Being a model car racer, I have a very thin silicone oil which I use the minutest of drops to lubricate the bobbin and then wipe the disc. Andy
I used Cillit Bang kitchen degreaser. I figured it would dissolve the muck - mainly brake dust - but not contaminate the discs too much. It took quite a while and lots of spinning to do it a with drill/driver, so hate to think how long it would take by hand.
Thanks. Didn't realise there was a spring washer in there. So I shouldn't expect much lateral movement of the bobbin itself then.
Took me maybe 30 mins or so. I used glass cleaner, An m6 nut and bolt, my drill, and a long reach 10 mm socket on an extension. I was surprised at how much black crap that came out. The front brake does initially bite nicer now. A worthwhile clean out.
Glass cleaner is a good idea. I couldn't find any in the house or garage... A faster drill is clearly more efficient. Took me way longer than that. Yes it's amazing how much crap comes out.
ing I just watched a couple of his youtube films and some of the advice he gives is dangerous. Most notable, don't bother replacing the o-ring when you split and caliper and re-use split pins that hold your brake pads in. Maybe people do this but I sure as heck would not advise the masses to do the same..
Everything on the internet needs a measure of judgement. First time I seen the bobbins video I checked on here first it was ok practice.
I can report that having done this has made a big difference to the brakes. They are sharper, more solid and more powerful now, with less distance to pull the lever before the brakes start to bite properly. Get cleaning those bobbins guys...
Or convert the rotors to full-floating and enjoy the rattle ompus: And never worry about seizing buttons anymore.
