Squeeky disc brakes, juddery front brake

Raniator
Raniator Posts: 40
edited July 2010 in MTB workshop & tech
Hi gang,

Just of late (the last couple of rides this week) my disc brakes are squeeky and the front one is quite 'juddery' when applied hard at speed.

I took the wheels of the other day so I could get to the hard to reach areas to clean and I think the problem has arisen since I put the wheels back on – could it be that the alignment is slightly different to before so the pads haven't aligned the same with the rotor and therefore causing the squeek?

When bought the bike the guy in the shop gave me some story about how the rotors are laser etched (or something) to get the effect and therefore rougher than some others and I might need to replace the fitted disc pads sooner than I might expect – maybe after a month (which to be honest sounds a bit odd to me).

I've got Stumpjumer Comp, had it a month now and done 100+ miles... could the above be true and they have worn out? Or is there some simple fix?

As always, all help appreciated!

Cheers.
Specialized Stumpjumper HT Comp 2010

Comments

  • .blitz
    .blitz Posts: 6,197
    What you describe is almost certainly due to some mis-alignment. My Juicy 3s go through various phases as the pads wear out ranging from a high-pitched 'violin in the distance' sound to good ole judder.

    If you also have Avids, simply loosen the alignment bolts on the caliper, apply the brake a few times while turning the wheel and then keeping the brake applied, tighten the bolts 1/4 turn each until tight.
  • Raniator
    Raniator Posts: 40
    Thanks .blitz...

    I guess taking the wheels off has mucked the alignment up. I'm a bit of a newbie when it comes to disc brakes so I'll have a crack at what you suggested and let you know how it goes! 8)
    Specialized Stumpjumper HT Comp 2010
  • Raniator
    Raniator Posts: 40
    OK, so I've been doing a little reading up... Apparently the Avid Elixir R brakes use a Tri-Align™ Caliper Positioning System™ and all I have to do is 'loosen the CPS™ bolts a little, and then squeeze the brake lever while re-tightening the bolts', which is what .blitz told me to do...

    Sounds easy... once I've figured out which bolt is the CPS bolt...

    Schweet!!!
    Specialized Stumpjumper HT Comp 2010
  • .blitz
    .blitz Posts: 6,197
    http://www.sram.com/_media/pdf/avid/AVI ... SetUp1.pdf
  • Raniator
    Raniator Posts: 40
    That doesn't show me which bolts are which, but still useful! :lol:
    Specialized Stumpjumper HT Comp 2010
  • Luke-Dob
    Luke-Dob Posts: 121
    CPS bolts are the ones that either:
    - Attach your brake to the fork directly (post mount)
    - Attach onto an adapter which threads into the fork.


    avid_cps_washers_and_bolts_2007.jpg

    These are the ones to loosen off.
    "If I Was Falling, YOU BETTER FREAKING CATCH ME!!!"
    6 years riding bikes, 8 broken bones, gravity can be a b**ch
    http://dobby.pinkbike.com/album/My-Bikes-D/
  • Raniator
    Raniator Posts: 40
    Cheers dude.

    I had a muck about got it sorted... went for a ride and they started squeeking a bit again but not as bad as before. I can cope with that, I'm sure they'll sort themselves out now, it aligns much much better than before :)

    It's due it's 6 week first service soon so I'll make sure the grease monkeys in the shop go to town on in and make it shiny and new and work nice :lol:
    Specialized Stumpjumper HT Comp 2010

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