• This topic has 20 replies, 12 voices, and was last updated 6 years ago by poah.
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  • Hideous screeching brakes in the wet/ cold.
  • bedmaker
    Full Member

    Any tips? Mine are doing my nut in recently.

    Local loop, it’s been endlessly slushy, icy, wet and muddy for weeks.

    The brakes are fine on the final descent where enough heat is generated to shut them up.
    It’s all the little bits in between where they are cold the howling noise is beginning to really wind me up.
    Today was on a brand new brakeset, new rotors cleaned with IPA before fitting. Bedded in in advance on the steep road behind the house. Still horrible.

    Anyone had any joy with facing mounts stopping this or is it just one of the many crappy parts of winter riding to be accepted?

    rockthreegozy
    Free Member

    Sintered pads? Mine were the same round Mugdock today, just one of these things!

    scotroutes
    Full Member

    Just pedal with your brakes held on occasionally. It’s nothing to do with contamination or wear.

    Splash-man
    Free Member

    Ear plugs….

    bedmaker
    Full Member

    YEah, might try sintered pads.

    I’ve tried dragging the brakes on any slight downwards incline to no avail.
    It seems to be slushy conditions that are particularly bad.

    13thfloormonk
    Full Member

    My SRAM Levels with centreline rotors did this, was awful. Mostly used them on my commute so they never got any heat in them.

    The closest I got to curing it was swapping rotors out for some with much more aggressive cut-outs, e.g. Magura Storm SLs.

    Also tried sintered pads, they made it worse plus squeeled in the dry also! Uberbike Kevlars were better.

    Eventually just went back to rim brakes, longer stopping distance in the wet but at least they’re quiet! 8)

    andreasrhoen
    Free Member

    Had – on one mountain bike – really problems with this issue as well.
    Front brake was much worse than rear so.
    Guess it’s also an resoance issue of disc, spokes, rim, fork, frame, tire.

    In other words: every bike is different….
    Easy to change: the brake disc

    Solution I found:
    cheapest Shimano disc and cheap organic pads.
    The Shimano disc I use appear to be very stiff in rotational direction. Some others are very “soft”. Had problems with the soft discs (the ones where the manufacturers nearly cut all steel away).

    Sintered pads, this bike: not possible to use them in wet conditions. Was a nightmare.

    But that’s typical where “resonance” is a problem. Changes in the system will tune the resonance.
    Sintered pads work on one bike – on the other you have to use organic ones. Third bike has no problems at all (like my cheapest bike).

    iainc
    Full Member

    Sintered pads in all my bikes here and live in wet and muddy west of Scotland. The gloop destroys resin pads. The sintered ones sometimes squeal a bit, often not, so we all get used to it as most folks are in same situation on our group rides.

    …always handy for alerting the Mugdock dog walkers of our presence too 😀

    andreasrhoen
    Free Member

    The closest I got to curing it was swapping rotors out for some with much more aggressive cut-outs, e.g. Magura Storm SLs.

    Fun.
    That’s neat.

    Magura Storm SLs

    were the worst on my bike. Too soft in my case…!
    🙄

    TrailriderJim
    Free Member

    Solution I found: cheapest Shimano disc and cheap organic pads.

    Tried this too, but the squeeling is still unbearable in the wet/cold.

    I wonder if the cause is bike cleaner I use contaminating the discs.

    tomd
    Free Member

    I used to suffer from this with my SLX brakes, it did my head in. Strangely the OEM Shimano pads don’t squeal and last really well so just use them now.

    andreasrhoen
    Free Member

    Guess it’s also an resoance issue of disc, spokes, rim, fork, frame, tire.

    all the above posts: really indicate that’s an resonance problem.
    And bike brands very often even test all possible combinations properly.
    Means: the bike manufacturer don’t even know why a certain combination makes on a certain bikes problems.

    If the “changing friction” on a wet disc is able to excite a certain frequency which is CLOSE to a system resonance – then:

    trouble! Or : the whole bike turns into a violin.
    A very, very bad violin…

    Any CHANGE in the system might help.
    No “setting” which works good for every bike.

    13thfloormonk
    Full Member

    Andreas has a point actually, although I managed to reduce the high pitched squeel on my SRAMs, there was stilla crazy amount of vibration travelling through the frame. I went through the motions with facing brake mounts etc. But the only thing which reduced it was a lead wheel balancing weight blu-tacked and sellotaped to the seatstay…

    andreasrhoen
    Free Member

    bike cleaner I use contaminating the discs

    possible as well.
    Worst if the pads are getting into contact of some fluid which isn’t supposed to be close to the pads…

    Possible to grind a bit of the pads off. Use fine sandpaper for that. Clean the rotor with alcohol or similar.

    Then you need to bed in the pads again. First braking will be very, very bad.

    But good chances, when biking in muddy, wet conditions: the evil problem is there again.
    Then it’s time to start changing components…

    Pads, rotors…

    andreasrhoen
    Free Member

    lead wheel balancing weight

    Nice Job!
    😈

    bedmaker
    Full Member

    Interesting on the resonance thing, the problem is much worse on my To rigid bike than on my ally Susser.
    Might wrap my seatstays and fork in Dynamat 🙂

    andreasrhoen
    Free Member

    Interesting on the resonance thing, the problem is much worse on my To rigid bike than on my ally Susser.
    Might wrap my seatstays and fork in Dynamat

    One of my bikes was really a hassle.
    Funny enough: was a long research project before it was fixed. Learnt that even the prestress in the headset affects the brake resonance crap.
    Years later: met a guy from the bike manufacturer and told him about this.
    He mentioned: “we know. This combination was big, big trouble”
    Only bad: the shop where I bought the bike and the company – at that time – refused to admit that there was a problem…
    😥
    But well – some money plus lots of “trying” – solved it finally.

    The bike had a Reba fork with Quick Release.
    All my newer bikes have thru axle and bigger stanchions.
    No problem there…?
    😯
    Future research project!
    🙄
    Don’t underestimate resonance in your life!
    👿
    8)

    Goldigger
    Free Member

    Try lightly sanding both the pads and disc braking surface with some fine Emery paper, clean with alcohol/brake cleaner.
    Then bed in hard..dont be gentle bedding them in.
    If your using sintered pads put them on the hob and cook them until they stop smoking.

    rickmeister
    Full Member

    Yep, resonance problem cured by using a Carbon fork not an alu one. The last thing changed after disc, pads, calipers….

    andreasrhoen
    Free Member

    @rickmeister-bloke:

    Yep, resonance problem cured by using a Carbon fork not an alu one. The last thing changed after disc, pads, calipers….

    Really?
    😛

    Or just joking…
    😥

    The fork has most influence onto the resonance.
    But really expensive “research” thing to change this…

    Changed really the fork???
    I went through all this crap – but without going so far.
    But if this

    Carbon fork

    is no joke…- would be great to hear…
    🙄

    poah
    Free Member

    sintered pads

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