Wednesday, August 30, 2023

Silencing your bike's disc brake in about 15 minutes. Basic Bicycle Maintenance.

Yes, I am wordy.  This needs either a video which there are plenty of them on youtube, or a lot of words.  I do words...

The time to do this is after you got caught out in the rain, or you are trucking your bike out to where you want to ride.  The bike now sounds like a screaming baby or a goat or some other animal.  Time to fix that!

If you followed the post on how to lube the wheel hubs on your bike, you probably have done exactly what I did.  Basically, I have a heavy hand when it comes to oiling things, so as you rode, your oil spun out of the hub and got on the brake disc.  Now your brake pads are "contaminated" with oil and stopping is more a matter of just how much grip strength you have in your hands rather than in the braking system on your bike.

Old school caliper brakes would most likely not be effected.

The overview is simple, braking surfaces have to be clean and free of grease, grit, and oils.  If there is oil, you slide.  That's why we use the stuff. 

To clean your braking system, there are steps and you can do it in your own home.  It takes me about 15 minutes once I have everything assembled.

Remember that anything you remove from the bike will be put back on the bike or you will need new replacements for future use.  Since most of these items are specialized, make sure they don't roll "under the couch" and are guarded for later.

First, get your equipment.

  • Rubbing Alcohol or Acetone (Remember perform this with adequate ventilation!)
  • Paper towels
  • Pliers
  • Optional light strength thread locker (Permatex Blue)
  • Sand Paper (I used 100 grit or "Medium" but a 200 or 320 grit might be better)
  • Sanding block or flat work surface to sand on
  • Towels or Cardboard sheet to protect the floors
  • 5mm Allen Wrench

Second, Lay the bike on its side on the floor.  Brake Disc side (left side) up.  You can do this on a bike stand if you have one, but I have found that it is just easier to do this with the bike on its side so the brake mechanism can rest on the spokes while you work instead of it dangling in the air.

Third, Locate the two Allen bolts that hold the brake mechanism to the frame/fork of the bike.  Use the 5mm Allen Wrench to remove the bolts from the bike and set them aside.  When removed, your brake mechanism should gently pull from the mount and the bike.  Note: if you are experienced at performing this work, and you have clearance on your bike, you may be able to get away with not removing the brake caliper from the bike.  I can't, you might.  Consider your situation first.

Fourth, using your Pliers, Bend back the end of the cotter pin so that it is straight.  If you
shear that end of the pin, you will need to make a trip to the hardware store to buy another one so be aware that it is possible to snap off the end, and that would be bad, mmmkay?  It will push back out of the mechanism, easily.  Set your pin aside with the bolts that held the mechanism to the bike.

Fifth, remove the brake shoes and the spring that holds them together and in place.  My own mechanism slid out of the brake mechanism easily.  Set the mechanism down so that it does not get damaged.

Sixth, using your Rubbing Alcohol or Acetone, clean the brake disc and the brake pads.  The disc and the brake pads must be free of oil and dirt when you complete these steps, and that includes the oil and dirt on your fingers. 

Seventh, cleaning the pads will leave some Rubbing Alcohol or Acetone on them.  This
will soften the old pads and the dirt.  Using the sandpaper and sanding block or flat work surface, sand the dirt and grime from the old pads.  I used 50 strokes per pad.  Clean both pads with Rubbing Alcohol or Acetone to remove the remaining dirt and create a smooth braking surface.


First, clean everything again.  Brake ring should be shiny and clean.  Brake pads should be clear of dust, grease, and grit.  No grit on anything, you will pick enough of that up on your nest workout, I am sure

Second, Make a Brake Pad Sandwich.  Best way to describe it.  Without touching the actual pads, the brakes are assembled to be put in the brake mechanism.  Pad, Spring, Pad.  Squeeze them together gently but firmly so the sandwich can be inserted into the mechanism.

Third, insert the Brake Pad Sandwich into the Brake Mechanism.  The holes in the two pads and spring must line up.  They are to be inserted into the mechanism with the holes lining up with those in the mechanism where you removed your cotter pin.

Fourth, Lock everything in place with the cotter pin.  The cotter pin should be lined up with the loop on the wheel spoke side of the brake mechanism.  Slide it in to the hole so that it extends out on the outside of the brake mechanism.  Everything must fit in easily, it will not take a lot of force.  Bend the end of the cotter pin in place.  The cotter pin will be mobile and able to turn.

Fifth, mount the brake mechanism back onto the wheel over the brake disc.  I do this by putting it on top of the mount and inserting the Allen Bolt into the screw holes then finger tightening the Bolts down.

Sixth, you are effectively done at this point but you do need to align your brakes.  Find the sight corridor within the brake mechanism.  The disc should be as close to evenly placed within that gap as possible.  When you spin that wheel, make sure that the brake does not engage at any point within the travel of the wheel.  If you are at that point, then you will tighten the Allen Bolts down using the 5mm Allen Wrench.  Test the wheel again to make certain you are not rubbing.

Finally, when you are out and riding your bike, you should break in or "bed" the brakes by GENTLY applying then releasing them.  Enough to stop your travel from about 6-12 MPH (10-20KPH) gently but firmly.  Everything should work "as it should".  If you are rubbing, then align the wheel to fit the brakes and repeat the alignment procedure as needed.

If that Goat has not been banished to the barnyard, or it's still squealing like Screaming Baby Airlines, repeat the process.

Remember, any noise and you're losing speed.  Take the time to align the wheels within the brakes so they may spin as freely as possible.

Yeah, it's a lot of words.  Get to work, it's not as hard as all this text.  I'll shaddap!

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