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[Closed] Why have my disc pads worn like this?

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[#2686309]

just noticed some odd grooves in my rotors and noticed the pads had worn like this,

[img] [/img]

the rotor was fine before I installed the new pads (superstar),

any ideas?


 
Posted : 23/04/2011 6:59 pm
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weird.

How long did they take to wear like that? Riding in wet / grit?

Do the grooves in the pad line up with the drillings in the disc? could grit / stones be trapped in the disc drillings?

did the pad swear down quickly? ( lessthan100 miles)

Waht type of pads? organic / sintered?


 
Posted : 23/04/2011 7:09 pm
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[img] [/img]


 
Posted : 23/04/2011 7:09 pm
 GW
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Who cares! even with those grooves they'd still work fine


 
Posted : 23/04/2011 7:12 pm
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TandemJeremy -

put them on 2-3 weeks ago, all dry riding,
grooves line up with the non-drilled part of the rotor,
200-250miles,
Semi Metallic/Organic,

pic of pads from above, there are some large metallic bits in the pads, but they located in the groove on the pads, points of least wear on the rotor,

[img] [/img]

rotor wear,

[img] [/img]


 
Posted : 23/04/2011 7:29 pm
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holy crap those rotors are well worn !!! ๐Ÿ˜ฏ


 
Posted : 23/04/2011 7:36 pm
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You need a new rotor, it has caused the pads to wear like that.

That said I've never seen a rotor wear that badly.


 
Posted : 23/04/2011 7:37 pm
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have you run a previous set of pads to the metal by any chance ?


 
Posted : 23/04/2011 7:39 pm
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Just one more rotor sir ?

[img] [/img]


 
Posted : 23/04/2011 7:43 pm
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Klunk - was using Superstar Kevlar pads previously


 
Posted : 23/04/2011 7:44 pm
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Using my skills of deduction I have found the cause of your problems.

Do you want me to say what the common denominator is?


 
Posted : 23/04/2011 8:06 pm
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Holy crap!!

How old are those rotors?


 
Posted : 23/04/2011 8:08 pm
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Jeez man, you need new rotors (and to maybe lay off the brakes a bit)!

p.s. this has nothing to do with the pads, just massively worn rotors.


 
Posted : 23/04/2011 8:12 pm
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That is well weird.

Sintered pads do increase rotor wear but thats a weird pattern for it to happen in

Just a guess but the disc has got hot enough to alter its properties adn become vey soft and thus wear?

Really odd tho. What make of discs?

Were the discs like this before?


 
Posted : 23/04/2011 8:12 pm
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the grooves in your pads are exactly where the raised sections on the rotors are. The pads have just worn to match the rotor. Time for new rotors and pads i think.


 
Posted : 23/04/2011 8:14 pm
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TJ, the pattern is due to the drilled holes. Wear is higher where the holes are as there is less material (and the pads are not completely rigid).


 
Posted : 23/04/2011 8:14 pm
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Sintered pads do increase rotor wear but thats a weird pattern for it to happen in
unworn ridges are where there's undrilled, continuous surface. I'd guess that's relevant - somehow

(bah, foiled by glenh !)


 
Posted : 23/04/2011 8:15 pm
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glen - could be but I have drilled discs using sintered pads and never seen anything like that - no variation in thickness at all. Years of heavy usuage


 
Posted : 23/04/2011 8:22 pm
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your rotor is wrecked it should be flat and smooth and the same thickness everywhere. I hade some hope ones that sort of tapered like a knife edge at then end and had been worn thinner with wear but bin those rotors and those pads now it is fubared
How old is that rotor?


 
Posted : 23/04/2011 8:22 pm
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wow that's some wear - look like Formula Oro rotors/pads. I'm off to check mine (superstar sintered pads / formula rotors)

edit: ah no not Oro... maybe RX/R1 etc? My Oro drill pattern has the holes sort of spiralling, not 2 concentric rings. Wonder why they changed the design?


 
Posted : 23/04/2011 8:46 pm
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Rx rotors, less than a year old, I do 400+ miles a month,
noticed the rear is going a similar way, but only noticeable by touch,
live and learn,


 
Posted : 23/04/2011 9:46 pm
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amt27 - Member
I do 400+ miles a month,
Try doing some of them with your hands off the brakes.


 
Posted : 23/04/2011 9:52 pm
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excellent advice ๐Ÿ˜†


 
Posted : 23/04/2011 10:20 pm
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If I were you, I'd put the pads back in then run them until the pads are worn completely. Then replace pads and rotors.

Impressive rotor wear, but the brakes still work fine, I presume?


 
Posted : 23/04/2011 10:36 pm
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djaustin - Member
If I were you, I'd put the pads back in then run them until the pads are worn completely.
Good advice. It's not like the disc is a safety-critical component or anything. ๐Ÿ™„

The braking surface of the disc is barely connected to the spider. I'd be wanting to replace that asap.


 
Posted : 23/04/2011 10:38 pm
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..if thats the state of the rotor, can you please show a pic of your cassette?

..and do you wheels wobble a bit and the crank make a funny noise?


 
Posted : 23/04/2011 11:30 pm
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As well as the two obvious grooves in line with the holes, there's a third groove which has worn the ends of the spokes of the disc just where they meet the disc its self.
I've seen truck brakes where thermal shock and wear have separated the braking part of a disc from the hub/mounting part. That one looks like it's about to do the same.

Edit;
Thanks to the wonders of google image search...

[img] [/img]

You really don't want to have something like this happen on a bike.


 
Posted : 24/04/2011 1:59 am
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I can't imagine its much fun in a truck??


 
Posted : 24/04/2011 7:42 am
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Depends which axle.
As far as I can remember, I've only ever seen it on trailers.
The driver wouldn't even notice losing one brake out of six.


 
Posted : 24/04/2011 6:25 pm
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That's a rotor design fault. I've never seen drillings in that sort of pattern, on an MTB or motorcycle - they are usually better distributed across the braking surface, like these XTs

[img] [/img]


 
Posted : 24/04/2011 7:05 pm
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That disc is brilliant!


 
Posted : 24/04/2011 7:15 pm
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That's a rotor design fault
agreed,

found out a mates formula rotor has similar wear, though not to the same extent,


 
Posted : 24/04/2011 7:22 pm
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And now on classifieds....
Wouldn't it have been better to just get another set of rotors and pads?


 
Posted : 26/04/2011 4:16 pm
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The photo of that rotor is brilliant! Never seen one that's worn that badly before.


 
Posted : 26/04/2011 4:22 pm
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Those brakes would still work fine. naff rotor design but I'd still use them until the pads wore out then replace the lot as said above.


 
Posted : 26/04/2011 4:47 pm
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Man, I thought my rotors had worn afair bit when I replaced them! Those take the biscuit!


 
Posted : 26/04/2011 5:22 pm
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coffeeking - have you noticed how thin they are where the braking track meets the spider?

dangerous IMo - bin immediatly


 
Posted : 26/04/2011 5:29 pm
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I've seen a lot of Formula rotors wear like that. The strip between the "dotted" holes seems to harden-up and wear less quickly than the rest of the braking surface.

At a guess, if the holes are punched or drilled out than the small gap between them probably means that the strip of metal is becoming case-hardened. Bit of a design fault really if that's the case.

My wife's bike plus our rental bikes all have formula brakes and are all showing this wear-pattern.


 
Posted : 26/04/2011 5:33 pm
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Yeah, still looks like a good ~0.75mm of material there, I'd be happy trusting it unless I was planning alpine descents (but then I'd be overhauling most of them already). (considering the wear rate of rotors normally being in microns per set of pads)

To be fair, the joint from spider to disc is "holed" and not solid, the shear area is low - it is probably pushing it a little but the disc looks very thick to start with, I'm fairly sure my discs are not that thick in standard form. And judging by the 100 miles to get that much wear I'd be giving those pads another 150 miles at most.


 
Posted : 26/04/2011 5:33 pm
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The pad material is too hard for the rotors and the wear pattern is consistent with the amount of circumferential rotor material.


 
Posted : 26/04/2011 6:09 pm
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yeah they would probably outlast the pads but I would not want topersonally test this.


 
Posted : 26/04/2011 6:13 pm