Cycling and bicycle discussion forums. 
   Click here to join our community Log in to access your Control Panel  


Go Back   > >

Bicycle Mechanics Broken bottom bracket? Tacoed wheel? If you're having problems with your bicycle, or just need help fixing a flat, drop in here for the latest on bicycle mechanics & bicycle maintenance.

User Tag List

Reply
 
Thread Tools Search this Thread
Old 03-26-11, 03:05 PM   #1
OLLY
Junior Member
Thread Starter
 
Join Date: Mar 2011
Bikes:
Posts: 5
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
disc brake squeal

Tried cleaning pads/rotors,squeal eventually returns
OLLY is offline   Reply With Quote
Old 03-26-11, 04:52 PM   #2
reptilezs
Senior Member
 
Join Date: Sep 2004
Location: boston, ma
Bikes:
Posts: 2,852
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
way too many factors to diagnose over the internet. for me proper bed in is the first line of defense
reptilezs is offline   Reply With Quote
Old 03-26-11, 05:20 PM   #3
FBinNY 
Senior Member
 
Join Date: Apr 2009
Location: New Rochelle, NY
Bikes: too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter
Posts: 30,843
Mentioned: 21 Post(s)
Tagged: 0 Thread(s)
Quoted: 870 Post(s)
Spray some Pam on it.
__________________
FB
Chain-L site

An ounce of diagnosis is worth a pound of cure.

“Never argue with an idiot. He will only bring you down to his level and beat you with experience.”, George Carlin

“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN

WARNING, I'm from New York. Thin skinned people should maintain safe distance.
FBinNY is online now   Reply With Quote
Old 03-27-11, 04:22 AM   #4
OLLY
Junior Member
Thread Starter
 
Join Date: Mar 2011
Bikes:
Posts: 5
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks
OLLY is offline   Reply With Quote
Old 03-27-11, 10:12 AM   #5
fietsbob 
coprolite
 
fietsbob's Avatar
 
Join Date: Jun 2010
Location: NW,Oregon Coast
Bikes: 7
Posts: 22,134
Mentioned: 18 Post(s)
Tagged: 0 Thread(s)
Quoted: 1124 Post(s)
Quote:
Tried cleaning pads/
With what? you should just replace the pads,
'cleaning' will just contaminate the friction material.
fietsbob is offline   Reply With Quote
Old 03-27-11, 02:59 PM   #6
slide23
Senior Member
 
slide23's Avatar
 
Join Date: Nov 2007
Location: Portland OR
Bikes:
Posts: 128
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
What I have found with stubborn disc squeal is that the pads are usually irretrievably scorched. I always use the same brand pad on all my disc bikes (Delta Aztec sintered). As long as the pad never gets overheated, I can run them down to the point where the pad spring gets pulled into the rotor, and never get a squeal. But a scorched pad will never stop squealing.

Replace and upgrade your pad.

Also, double check the alignment of the calipers. If you're running Avid brakes, just run through the alignment process.
slide23 is offline   Reply With Quote
Old 03-28-11, 02:55 AM   #7
OLLY
Junior Member
Thread Starter
 
Join Date: Mar 2011
Bikes:
Posts: 5
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks,what would you recommend for an upgrade for a Hayes 98-20197?
OLLY is offline   Reply With Quote
Old 04-04-11, 01:14 PM   #8
slide23
Senior Member
 
slide23's Avatar
 
Join Date: Nov 2007
Location: Portland OR
Bikes:
Posts: 128
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I'm not ignoring you; I just have no clue what works best with Hayes.
slide23 is offline   Reply With Quote
Old 04-05-11, 07:48 AM   #9
Woodwind314
Member
 
Join Date: Apr 2011
Bikes:
Posts: 42
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I don't know if this will work with disc brakes, but with squealing / chattering rim brakes there is a 'magic' cure:

Clean rim and pads. Then spread a tiny amount of motor oil on the rim with your fingertip. Just a few drops.

Do a bit of test braking. At first, you'll hardly get any braking power. After 5-6 attempts, braking power comes back - minus the squeal.
Woodwind314 is offline   Reply With Quote
Old 04-05-11, 08:50 AM   #10
slide23
Senior Member
 
slide23's Avatar
 
Join Date: Nov 2007
Location: Portland OR
Bikes:
Posts: 128
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by Woodwind314 View Post
Clean rim and pads. Then spread a tiny amount of motor oil on the rim with your fingertip. Just a few drops.
Uh, don't do that. At best, you will contaminate the disc pads as they are porous. At worst... well, think about it.
slide23 is offline   Reply With Quote
Old 04-05-11, 02:09 PM   #11
Woodwind314
Member
 
Join Date: Apr 2011
Bikes:
Posts: 42
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by slide23 View Post
Uh, don't do that. At best, you will contaminate the disc pads as they are porous. At worst... well, think about it.
As I said, I don't know if it works with disc brakes. Works like a charm on rims...

Thinking about automobile brakes, a little oil or grease on the brake pads is not problematic. At worst, you get some burnt oil smell the next time you brake hard.

The idea behind the oil trick is that brake squeal results from slip-stick. Or rather, from a large difference between the stationary (stick) friction, and the sliding (slip) friction. The oil decreases stick friction much more than slip friction, at least between rubber pads and aluminium rims.

It might work with other material pairings as well.
Woodwind314 is offline   Reply With Quote
Old 04-06-11, 02:08 AM   #12
greyghost_6
Pleasurable Pain
 
greyghost_6's Avatar
 
Join Date: Aug 2006
Location: Bloomington, IN
Bikes: Voodoo Rada, KHS Alite 4000, Smith & Wesson Tactical, Diamondback Response
Posts: 350
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Some disc brakes are just squeaky no matter what you do to them (in my experience). What I used to do is lightly sand the rotors and dust off with rubbing alcohol swabs making sure not to brake during the cleaning and contaminating. Also maybe the calipers are not "clapping" on the rotor parallel to each other. Probably time for new pads and a good adjustment.
greyghost_6 is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -6. The time now is 08:59 PM.