Advertise on Bikeforums.net



User Tag List

Results 1 to 10 of 10
  1. #1
    Newbie
    Join Date
    Sep 2011
    Posts
    2
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Does the wheel have to be perfectly centered between the break pads?

    I just bought a Specialized Hardrock, and after taking off the front wheel with the QL level I'm finding it hard to reinstall without it being slightly off center. Even if it appears (as far as I can tell) to be centered, when I ride it there is still a very subtle scraping noise. Will riding it like this eventually cause damage? How can I fix this? Thanks

  2. #2
    Senior Member
    Join Date
    Apr 2009
    Location
    New Rochelle, NY
    My 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
    22,556
    Mentioned
    69 Post(s)
    Tagged
    1 Thread(s)
    You're looking at things backward.

    The wheel should be centered in the fork or frame, and the brakes adjusted to the wheel. Then as long as the brakes are roughly centered so neither side rubbing when open they're fine. Better centering allows for closer adjustment, but once the adjustment has the lever throw where you want it, more even centering isn't any better.

    BTW- Get in the habit of closing the QR with the bike vertical on level ground. This ensures that the wheel is always in the same place, firmly against the tops of the dropouts. If that isn't centered in the fork or frame, see the local dealer and see if they can resolve it. (better bikes will or should be spot on, less expensive bikes aren't built as closely and might not be, but this can be corrected).
    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.

  3. #3
    Junior Member
    Join Date
    Aug 2010
    Location
    Bostonish
    My Bikes
    2002 GF Sugar 4 with a few modifications
    Posts
    14
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Hard to tell based on the info, but you could either 1) have a warped rim or 2) have the wheel sitting incorrectly. Both are fixable problems.

  4. #4
    Senior Member Monster Pete's Avatar
    Join Date
    Apr 2010
    Location
    Warwick, UK
    My Bikes
    2000-something 3 speed commuter, 1990-something Raleigh Scorpion
    Posts
    1,048
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Brake, not break (unless it's broken) Sorry, pet hate of mine.

    If the pads are consistently misaligned, I don't think it will be a problem with the trueing of the wheel, which would more likely manifest itself as a wobble than a dishing problem. It's possible that the wheel isn't seating correctly in both dropouts. Even a tiny bit of ingrained dirt causing a fraction of a mm difference will be amplified by the time it gets to the rim. Check the dropouts for dirt and damage, and install the bike onto the wheel, rather than the wheel onto the bike if that makes sense. Of course, it could just be that the brake pads need adjusting properly.
    I've got a bike, you can ride if you like it's got a basket, a bell that rings and things to make it look good- Pink Floyd, 1967

  5. #5
    vol
    vol is offline
    Senior Member
    Join Date
    Jul 2010
    Posts
    2,637
    Mentioned
    6 Post(s)
    Tagged
    0 Thread(s)
    I had the same problem but it seemed to have been corrected by the LBS. I saw they just adjusted the very tiny screw. But I have another annoying problem: when I hit the rear brake, it makes loud noise from the friction between the rim and brake pads. It's so loud and attention-attracting that I now only use the front brake. I cleaned the rim well and can't find the reason and how to fix it.

  6. #6
    I let the dogs out AlphaDogg's Avatar
    Join Date
    Apr 2011
    Location
    Boulder, CO
    My Bikes
    2011 Fuji Roubaix 1.0, 2003 Ti Merlin Solis, & 1994 Raleigh MT200
    Posts
    1,934
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    ^ Your rear brake pads are contaminated. You will need new ones.
    Quote Originally Posted by Andrew R Stewart View Post
    Weird spell/word check. "***" is "***". I'll never understand this computer. Andy.

  7. #7
    Senior Member bikeman715's Avatar
    Join Date
    Mar 2008
    Location
    Salinas , Ca.
    My Bikes
    Bike Nashbar AL-1 ,Raligh M50 , Schwinn Traveler , and others
    Posts
    2,079
    Mentioned
    2 Post(s)
    Tagged
    0 Thread(s)
    to vol, try toeing in the pads and clean the pads and the rims with alcohol .
    bikeman715

  8. #8
    Senior Member mrrabbit's Avatar
    Join Date
    Dec 2007
    Location
    San Jose, California
    My Bikes
    2001 Tommasini Sintesi w/ Campagnolo Daytona 10 Speed
    Posts
    3,186
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    1. Wheels are to be properly dished.
    2. Those wheels are to be centered between the stays when installed.
    3. The brakes are to be themselves centered around the wheels. (Brakes have their own centering adjustments...)

    =8-)
    4000+ wheels built since 1984...

    Disclaimer:

    1. I do not claim to be an expert in bicycle mechanics despite my experience.
    2. I like anyone will comment in other areas.
    3. I do not own the preexisting concepts of DISH and ERD.
    4. I will provide information as I always have to others that I believe will help them protect themselves from unscrupulous mechanics.
    5. My all time favorite book is:

    Kahane, Howard. Logic and Contemporary Rhetoric: The Use of Reason in Everyday Life

  9. #9
    vol
    vol is offline
    Senior Member
    Join Date
    Jul 2010
    Posts
    2,637
    Mentioned
    6 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by AlphaDogg View Post
    ^ Your rear brake pads are contaminated. You will need new ones.
    Quote Originally Posted by bikeman715 View Post
    to vol, try toeing in the pads and clean the pads and the rims with alcohol .
    Thanks a lot (sorry I had forgotten this thread). I just cleaned the pads and the rims with alcohol. (Didn't remove the pads as I've never done it and don't know how and don't want to make an unsafe mistake. I just inserted a thin alcohol paper between brake pad and rim.) Apparently the pads are contiminated with a lot of tri-flow that got on the rims. Now it makes no squeaky sound any more.
    Last edited by vol; 09-05-11 at 10:54 PM.

  10. #10
    Junior Member
    Join Date
    Sep 2011
    Posts
    13
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    The brakes, and in particular their balancing depend on the wheel being centered in the wheel arch for good adjustment. The balance springs of brakes are only designed to handle a small range of adjustment. As others have suggested, make sure that the wheel is centered, and to do that hold it centered while the fastening is done, and make sure that the weight of the bike is applied; do not fit the wheel when it is off the ground. Then adjust the balance screws and possibly the brake gaps to get the blocks free of the rims and to the right distance.

    Other things to note are whether or not any of the ferrules (the metal bits on the cables) have popped out of position, that the springs on the brake arms have not come out, and that the wheel has not developed a wobble. Eventually,a wheel takes on a slight wobble that leads to the need for wider brake gaps or the adjustment of the wheel to correct the problem.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •