Disk Brake Question

[Mr Pig]

I know this is the wrong section but I wanted a quick answer, you can bin it once it's done.

I've just got my new bike home, a Genesis Altitude 00. Looks nice, something dead cool about a brand new bike, but I have a possible problem. The brake disks are coated in oil.

I always understood that oil contamination on brake pads was the kiss of death, as there was no way to satisfactorily remove it. Is the same true of bike brake pads? I can clean the disks off with IPA no problem but should I be phoning the shop asking for new pads or will they be ok?

Just want to know before I phone the shop tomorrow and give them a hard time ;0)

 

[RedBike]

If you've got all on your pads then they're ruined.

 

[RedBike]

You can normally burn smal amounts of oil off. Just drag the brakes for a bit and get them hot.

Your brakes wont work right until they're bedding in anyway.

 

[Mr Pig]

It's like oily graphite. like a thin smear of it on the rotor but it's obviously came off the pads because it's only on the part the pad runs on.

It could be normal but not having used bike disk brakes before I don't know.

 

[RedBike]

oily graphite?

I'm not sure what you mean by that; but there shouldn't be any oil/grease on the discs.

 

[Mr Pig]

oily graphite? I'm not sure what you mean by that

It's like graphite powder, but oily. That's pretty much all I can say about it. It's not 'clean' oil and it's not dry powder. I'm not using the bike until I've spoken to the shop tomorrow.

It looks to me like oil on the disks has picked up dust of the pads.

 

[ratty2k]

Its possibly something they put on for staroage to stop the discks rusting slightly? IPA will clean the discs perfectly well, and you can remove the pads and give them a clean with it as well. If the pads are heavily contminated then a quick rub on some wet and dry or smooth (ish) sandpaper will remove the worst, again followed by a rinse in IPA.
Make sure you do some short sharp stops from speed to bed the new brakes in, they may well feel a bit poor at first, but will soon 'come in' and work properly.

 

[mickle]

The general consensus is that if there's any oil whatsoever on the pads they should be discarded, it seeps right in to the pad and no amount of sanding or use can get rid of it.

 

[Globalti]

The discs should be absolutely oil-free and spotless. Being stainless they won't rust so no oil is needed to protect them. If the brakes haven't been used you might get away with just cleaning the discs with alcohol and giving the pads a good clean in hot water with detergent. You could even put them in a dishwasher as nothing gets hotter or more caustic for effective degreasing.

 

[Mr Pig]

I'm not farting around with them . It's a brand new bike, if they're not right they can give me new ones. I phoned this morning and they were fine about it. THey said that they will squeal if they have oil on them and if they do just to let them know and they'll fit new pads.

 

[RedBike]

THey said that they will squeal if they have oil on them

New pads/ disc often squeal anyway until they're bedded in!
Deore discs are famous for it in the wet. The way to notice is that your brakes will be nothing like as powerfull as they should be.

Clean the rotor then bed the brakes in normally. It sounds like your brakes have leaked. http://cycleworksusa.com/page.cfm?pageID=137

 

[Globalti]

If the discs are contaminated with oil they will work okay but will make a sort of squawking vibrating noise as you come to a halt.

 

[RedBike]

If the discs are contaminated with oil they will work okay but will make a sort of squawking vibrating noise as you come to a halt.

The brakes will loose a lot of power.

If the pads are contaminated on a new bike then he should be asking for them to be changed. I would also ask for the shop to clean or replace the rotors.

The trouble is he wont be able to tell until the brakes are bedded in. Brand new brakes will squeal and lack power for the first few stops anyway.

 

[ratty2k]

Some squeal anyway, quite often when they get wet.
Oil contaminated pads will at best be underpowered for a bit, at worst (I've had stuff given me like it) they wont do much at all.... front pads on my last bike were contaminated by the LBS, you could pull on the lever as hard as you wanted, the wheel kept turning....