Disc brake adjustment...going mad!!

The fact you've bent it back a few times already may have something to do with it. See if you can get the rotor on a flat surface.
 
02gf74":1gjrjkcf said:
bren":1gjrjkcf said:
Sticking my 2p in here....
My money's on the hubs moving about in the dropouts though.

I'm not so sure - the spindle should rest against the drop out cut out - obviously vertical drop outs are better, then the axle nut usually has serrations that dig into the drop out, the whole caboodle kep in place by the QR. I need to measure it by the QR spindle but cannot be much more than 3 mm in diameter, that is not strong enough to hold the axle in place, and it doesn't - it provides the clamping force so the shear plan is not in the QR spondle but in the axle it self.

indeed, but in my case (vertical dropouts, IS mount and apparently crap skewers) the clamping force from the skewer just isnt enough to stop the left side of the hub axle from shifting downwards. its only fractions of a mm, and it takes a really hard, back wheel lifting kind of a stop to do it, but its enough to make the disc rub the pads. As the OP has found, leaning the bike over to one side counteracts this temporarily.
ive just looked at the dropouts on the forks and the paint damage and marks in the alloy back this up. the wheel has been moving on one side.

if you cant get to the bottom of it, i would lose some fluid too, means more lever travel til the pads bite, but will give more pad-disc clearance to allow for warps and dirt.
 
Right well after 2 hours of tinkering I can say this.

- The linkage bolts on the swing arm were able to be tightened but like half of a quarter turn.

- There is very slight lateral movement when pulling the swingarm side to side and looking down on it...but only a couple off mm each way

- The pads seem to return un-evenly even after pushing them back. One side doesn't seem to go fully back.

- The travel on the lever at the moment is such that it can be pulled to touch the grips...

- The skewer doesn't appear to be moving

I've attatched some pics of the brake in question...maybe seen flying through the air into a neighbours garden any time soon!

Oh the xt is an M765...

Wook
 

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Sounds/looks like lubing your pistons should be the next thing to do and see if that solves anything.
 
cyfa2809":30q924v5 said:
Sounds/looks like lubing your pistons should be the next thing to do and see if that solves anything.

Im afraid I have no idea how to! Is it something I should tackle or leave to the LBS?
 
It's pretty easy. I used to have the Saint version of your brakes and the pistols did need the odd clean and lube.

All I used to do I to remove the wheel and pads, the pull the lever o that the pistols protruded, cleaned them with brake cleaner then applied lots of mineral oil and the pushed them back in.

It does look like you have a build up of mud, dust and braking dust around the pistons.
 
I did just that this afternoon removed the pads and cleaned and lubed the pistons. However one of the pistons still doesn't seem to return fully in...is this because of some "auto pad wear adjustment"? I've got them so there is still slight rubbing but only really on hard cornering. When coasting in a straight line they are ok but under real hard pedalling slight rubbing too. I got fed up and went out for a ride anyway! They are the best they have been for weeks but still not rub free!! GGggrrrrr!
 
Yep mindmap has it. Site is very slow for me today.
How are you pushing the pistons back? I normally use an 11mm spanner, the closed/round end and 'walk' them back. If one pops out and another doesnt, it has been suggested to cable tie the one that keeps poppoing out.
 
On my old saints I'd push the rotor against the lazy piston whilst pulling the lever. This used to do the trick and get them working together.

Failing that I'd be lazy and centre the brake accordingly and leave it as. I found with mine that I'd get some rub round corners, but I was running 203mm rotors.
 
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