Brake Pad Grime - harmless or not?
KonaKurt
Posts: 720
I am using standard Hayes Sintered Brake PAds in my Hayes 9 HFX brakes, which perform great! But frequently, I get a build up of what I assume is worn down pad, black/grey powdery grime, seeping out of the calipers.
Obviously, things get dirty, that's not my point here! I am just wondering if allowing this stuff to get back onto the rotors is something to worry about or not. What exactly isit, carbon? Does it contribute towards common 'rotor squeal'?
KK.
Obviously, things get dirty, that's not my point here! I am just wondering if allowing this stuff to get back onto the rotors is something to worry about or not. What exactly isit, carbon? Does it contribute towards common 'rotor squeal'?
KK.
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Comments
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The crud that you get sticking to you calipers is what is commonly known (oddly enough) as "brake dust".
It's a mixture of trail muck, steel, brass and whatever else is used in the pads. Basically, it's your pads and discs in liquid form. It's nothing to worry about and is perfectly normal.
To answer your other question, Carbon is a chemical element, symbol C, atomic number six and part of group 14 of the Periodic Table, making it tetravalent (i.e. it has four electrons available to form chemical bonds).
It has three known isotopes, C12, C13 and C14. 12 and 13 are stable, whilst C14 is radioactive and has a half-life of 5730 years (Carbon 14 is the isotope used for Carbon Dating - the rate of decay indicates how old the object being tested is, to within ±300 years or so).
Carbon has three known allotropes - amorphous carbon, graphite (used in pencils and carbon fibre) and diamond, the hardest naturally-occuring substance known.
Carbon in all it's forms is the fourth most abundant element in the universe (hydrogen, helium and oxygen being the three most common, in that order). It is present in all organic compounds.
Who says that mountain biking isn't educational?0 -
Damn. I always said I`d avoid carbon bike bits. Obviously not :shock:0
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Biggest carbon bit on my bike is me
I tend to give the calipers a good swill through and take the pads aout from time to time clean, don't know whether it improves things but doesn't seem to do any harm.It's easier to ask for forgiveness than for permission.
I've bought a new bike....ouch - result
Can I buy a new bike?...No - no result0 -
Dave, you really need to get out more!
I wouldn't panic too much about brake dust. Your car puts up with it for probably it's entire life without complaint.
I occasionally pop my calipers, with pads in, into an ultrasonic bath that I bought from ebay for 20 quid.
10 minutes in that and they are clean and spangly. Still rubbish though.
Joe.0 -
Joe_Pineapples wrote:Dave, you really need to get out more!
Actually, I just paraphrased it from WIkipedia!!
Contrary to popular belief I'm not THAT sad.... :shock:0 -
Thanks Dave, for that highly precise answer and insight into the world of Carbon!
So I am taking that to mean that this brake dust is completely harmless, even when dabbed onto rotors.
Joe: Ultrasonic bath?!?! Sounds like an interesting piece of kit!..
KK.0 -
Brake dust is harmless, it'll just wash off when you clean the bike.
Don't laugh at the ultrasonic bath, it gets a lot more use than you'd imagine and you should see how good it cleans a rear cassette!
http://www.maplin.co.uk/Module.aspx?ModuleNo=225671
Joe.0 -
Joe, no I'm not laughing actually, I'm really interested!! Sounds very useful!
Have you got a picture of it, or more details... I might want one!
KK.0 -
Click on the link in the post above and it'll take you to the wonderful world of sonic cleaning!
But seriously, it's a great wee gadget. Bike parts tend to be caked in dirt and grime most of the time and no matter how well you think you've cleaned something, this little pixie will vibe out lots more.
We use them at work for cleaning just about anything.
Joe.0 -
Just to get back to the matter at hand for a moment...!
I do find 'brake dust' a bit of a pain, in that it seems to create bad rotor squeal sometimes, the kind that resonates throughout your spokes, scaring dogs and cats for miles..! I find it tricky to get out of my calipers at that stage.
Mind you, muc-off disc brake cleaner seems to do the trick!
KK.0 -
Consider applying a tiny smear of Copaslip to the BACK of the pads.
Joe.0 -
Ah! Good idea Joe. I can see how that would help damp vibration from the pads
KK (with a long lin of cats and dogs chasing his rotors down the road....)0 -
That is one of the applications that Copaslip is designed for.
I smear a light coating on the back of new pads when I fit them.
Joe.0 -
Careful!!
Some people get a weeny bit upset if you mention "copper grease" and "brake pads" in the same sentence... :oops: :shock:
(Not me BTW!!)0 -
My cars, my motorbikes, my mountainbikes, they've all always had Copaslip on the back of their pads and will continue to for as long as brake pads are around.
I'm not preaching to anyone, just offering an opinion on Kurt's problem, but let's be honest, it can't hurt.
Give it a go, it might help, it might not.
Joe.0
