Problems with brakes

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Problems with brakes
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flag Havis
Posted: Sep 19, 2013 at 10:53 Quote
Hi!

I just bought a new disc rotor and new brake pads to my DH bike. I have Shimano M575 brakes and resin pads because the rotor cant have metal pads. They feel very inefficient and I cant even "lock" the brakes. Yes I have added mineral oil and it's okay, but the brakes aren't. Is it just because the parts are brand new and they need to be driven so the rotor gets a bit rough or can there be some other reasons why my brakes won't work as they should?

Thank you!
flag oldmanDan
Posted: Sep 19, 2013 at 14:30 Quote
All brakes need to be bedded in. This takes a little while, the fastest way is to find a big hill, roll down with the brake on, squeezing really hard. When you stop, pour some cold water over the brake and pads.
Do this a few times, and the rotors start to look shiny meaning they are bedding in.
flag iareconfuse
Posted: Sep 20, 2013 at 21:43 Quote
New rotors require a bed-in period. You're basically depositing pad material onto the surface of the rotor. After a few hard stops you should be feeling the proper amount of stopping power you'd normally expect from your brakes.

To bed in my rotors all I do is sprint around the neighborhood a few times and grab the brakes to the point right before they lock up the wheels. Do this about 10 times to the front and rear brakes (separately) and you should be good to go.
flag Havis
Posted: Sep 22, 2013 at 9:47 Quote
Okay, so I think there is oil in my brake pads because they havent got any better even though I have ridden very much. Brake works better if the lever is very wet. For example after a bike wash.
flag bigburd
Posted: Sep 22, 2013 at 14:03 Quote
Take the pads out and sand them till clean pad comes through , and clean the disk with white spirit or isopropyl alcohol and a rag.
flag iareconfuse
Posted: Sep 22, 2013 at 18:26 Quote
You'll know for sure if you have some sort of contamination on your rotor. It squeals when you brake.... usually pretty damn loud too. To remedy this I usually sand the rotor surface and the pads, clean both with isopropyl alcohol, then repeat the bed-in procedure.
flag brianl
Posted: Sep 23, 2013 at 11:28 Quote
if sanding and/or solvent doesn't get the pads clean, then cooking them (to burn off the oil) might work.
flag Havis
Posted: Sep 23, 2013 at 12:59 Quote
Thank you everyone! Yes it "squeals pretty damn loud". Next thing I do is that I'll take of pads and rotor and then sand them. After that I might clean them up with a good "brake cleaner" (Würth).
flag Quebec2010DH
Posted: Sep 23, 2013 at 14:40 Quote
New set of pads will do the trick too. If I can ask, what kind of rotors can only be used with Resin pads? You'd be much better off with sintered, imo
flag ajax-ripper
Posted: Sep 24, 2013 at 4:51 Quote
Quebec2010DH wrote:
New set of pads will do the trick too. If I can ask, what kind of rotors can only be used with Resin pads? You'd be much better off with sintered, imo
I forget what the model number is but one of the entry level shimano rotors is only to be used with organic pads.
flag Havis
Posted: Sep 25, 2013 at 12:05 Quote
I just cant understand my brakes anymore. I sanded my pads till they started to look perfect. I even sanded the rotor a bit. I also cleaned them up with a Brake Cleaner spray. They just don't have any grip (I can't even lock my rear brake).
But after I have washed my bike and my pads and rotor are wet, the brake works PERFECTLY. I just fcking cant understand. If someone knows what is wrong, please tell me because I'm starting to freak out when I cannot ride.

Thank you
flag bigburd
Posted: Sep 25, 2013 at 13:11 Quote
Used disk brake cleaner once , won't do that ever again ! made my brakes 4 times as bad as before cleaning them.

Discs and pads are so cheap that you may as well buy new ones , super star components do them cheap as chips , that way there is no way either are contaminated.
flag iareconfuse
Posted: Sep 25, 2013 at 14:32 Quote
If you JUST sanded and cleaned your brakes, then yeah you're probably going to need to repeat the bed-in procedure to get them interacting with the rotor well. If it doesn't clear up after a few hard stops I'd just consider getting some new brake pads.
flag Havis
Posted: Sep 25, 2013 at 23:15 Quote
If I decide to buy new pads, I will buy new rotor too. I'm starting to think "Buy cheap and then buy good" here.
flag Havis
Posted: Sep 26, 2013 at 13:00 Quote
oldmanDan wrote:
All brakes need to be bedded in. This takes a little while, the fastest way is to find a big hill, roll down with the brake on, squeezing really hard. When you stop, pour some cold water over the brake and pads.
Do this a few times, and the rotors start to look shiny meaning they are bedding in.

I succeeded with this system! My brake is now feeling good, and I hope it will stay good too! Thank you everyone for answering to me!
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