Buggington

I'm back again - all I seem to do is post in the mechanics section of this forum

Anyways, I'm taking my bike into the shop soon and something reminded me about cleaning brake discs. I've ridden about 550 miles on my bike and have never cleaned my brake discs. The colour difference is quite noticeable from the (no idea what the technical vocab here is) stem type things that attach it to the hub, and the part where the actual pads touch.

It's a sort of black-ey colour where the pads touch and on the stem-ey things it's just a normal stainless steel colour.

So, my question is, how often should I clean them? Is the black-ey stuff going to do anything to the braking performance? Is this a sign of something happening with the pads? And if I need to clean them, what do I do?

Thanks for any replies,

Buggington

reptilezs

black streaks indicate contamination and loss of power. clean rotors with alcohol. look into getting new pads. what model brakes?

Zef

booolkaakaa!

Not necessarily a reason to get new pads. Brake dust is a natural by product of using disc brakes and dirt will naturally find its way onto the system as it is an open system. You only need new pads if you got grease/oil/other lube on the current pads or they are worn to the point of needing replacement. Agree with the recommendation of cleaning rotors with alcohol.

The black stuff is most likely caused by the dust created as the pads wear down + other dirt mixing in with it. If your brakes feel solid and are providing you enough stopping power then just clean the rotors and leave everything alone until you NEED to replace the pads. If you feel the need to clean things up then use a rag dampened with water or alcohol to clean things up around the brakes...better yet lookup the instructions on how to remove your pads and remove them before cleaning the area, then replace after wiping everything down with a damp rag. Clean as often as you feel necessary. But don't sweat it too much, just get out and ride.

-j

Buggington

Awesome, thanks for the replies!

So what kind of alcohol should I be using? I'm guessing beer wouldn't do the job

SchizoSheep

i.e. smartprice vodka, a bottle for you, a bottle for the bicycle

The alcohol is a solvent, which will clean up the grease and oil, and the water and ethanol combination will dry quickly.

jimc101

You could use some bike specific products, like Fenwicks Disc brake cleaner https://www.fenwicks.info/bike.htm should be available in a bike shop near you, if going for alcohol, you want IPA (Isopropyl Alcohol), for small 500ml bottles, a chemist (probably not Boots) should be able to supply, for larger supplies, check out industrial suppliers or ebay.

Looigi

Mine are discolored from heat generated during long fast descents. No cleaning necessary.

Buggington

Following Looigi's post, I'm now no longer sure if it's just brake dust etc. So, I've taken some photos and I've attached it below. On the right is my brake disc and on the left is my Dad's. My Dad's is clearly a lot cleaner, and if you compare the colour of his stem-ey things to the colour of my rotor (I've now found mine has black stems) there's a massive colour difference.

When I clean them, should I use some sort of scourer? Would it help?

Thanks,
Buggington

BCRider

If you ride in the wet or in mud more often than your dad then some pad dust or just road dust on the rotors is not a big deal. Although the smears you have indicate that your pads may have picked up some small drops of road splash oil.

Either the rubbing alchohal from the drugstore or a shot of brake cleaner solvent that you can get from any autoparts place will clean the rotor itself just fine. Just keep using fresh paper towels to wipe and clean until the towel with a bit of solvent on it comes away clean. It wouldn't hurt to shoot some brake cleaner at your pad faces, let sit for a half minute and then shoot them again to encourage any oils on the pad material to flush away. Some have even found that boiling the pads in water really helps to remove any oil contamination. Although if they are getting well down in thickness then it may be easier to just replace them.

Buggington

I do ride in the mud quite a bit - though most of my miles and braking are done on the road. I will try to get hold Of some brake cleaning solvent, but if I can't, my dad has come up with a zany idea - how about using t cut?

jimc101

They look pretty normal, would be more concerned with the QR skewers, the one on the round rotor wheel would be better on the other side, so it has no chance of ever going into the rotor, the one with the wavy rotor some corrosion, I wouldn't want to see any corrosion in that area if possible.

For the T-Cut idea, only if you don't want your brakes ever to work again, proper brake cleaner will be a lot cheaper too.

BCRider

I don't know what T-cut is. But unless it's a degreaser that evaporates to leave no sign of residue then avoid using it. You don't want any oils, waxes, fats, paints, clear coats, silicone or anything else that leaves anything behind at all on your rotor faces and pads. The only thing allowable would be a strong soap or detergent followed by a generous rinsing.

jimc101

T-Cut, great for polishing out little scratches on your car, not great or polishing disc rotors https://www.carplan.co.uk/index.cfm?category=58

Buggington

Thanks for all the advice. In the end, I just bit the bullet and went out and bought some brake disc cleaner.

Haven't tried it yet, but it says on the can it should work

BCRider

That T-cut almost certainly has waxes in it along with the polishing compound. Definetly not a good idea.

The brake cleaner will come in very handy for lots of cleaning jobs where you don't want to leave any oily or waxy residue behind. So it's not like it's money wasted. It's good stuff to have in the shop's arsenal. But I know it's not cheap so only use it where it's the right thing.

Buggington

The whole can was only £3.99 - I don't know what I was complaining about!