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Brakes rubbing ! HELP !!!

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  • 24-08-2012 10:45pm
    #1
    greenspurs
    Registered Users Posts: 10,218 ✭✭✭✭


    My back brake is rubbing on the rim of the wheel..
    I have tried loosening the nuts that holds the brakes to the frame, i have loosened the nut on the brake itself, and tightened and loosened the cable...
    I open out the brakes, and the wheel spins free, pull the brake and the blocks are clamped to the frame.. Its as if the brake wont "release" the blocks. The wheel isnt buckled :)
    Please help !!!
    247469249_2017413731748359_7675802031635703098_n.jpg

    "Bright lights and Thunder .................... "



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    #2
    doozerie
    Registered Users Posts: 4,830 ✭✭✭doozerie


    If the brake calipers are not opening back up again after you release the brake lever then it could be due to a number of possible problems, including:

    * The inner brake cable is catching and not providing the slack for the calipers to open out. See if you can pull the cable by hand from the caliper end to feel for restrictions in the cable.
    * The caliper is sticking because the bolt(s) holding the two "sides" of the caliper together are tightened too much (or they are simply contaminated with dirt which is impeding the movement). With slack in the brake cable try squeezing the calipers together (i.e. pushing the brake pads towards the rim) by hand and release them and see if they open/spring back out.
    * The spring on the calipers is dislodged or broken. As above, try to squeeze the calipers together just using your hand, to see if they open back out again, which should help narrow down the cause.


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    #3
    greenspurs
    Registered Users Posts: 10,218 ✭✭✭✭greenspurs


    I can squeeze em together by hand.... The Spring is in place, and ive tried it with it the nut tightened and loosened ..... It does seem as there is too much Play/slack in the cable ....
    247469249_2017413731748359_7675802031635703098_n.jpg

    "Bright lights and Thunder .................... "



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    #4
    greenspurs
    Registered Users Posts: 10,218 ✭✭✭✭greenspurs


    i can pull the lever nearly all the way to the handlebar, The cable runs beneath the cross bar , and it is loose/sagging.
    When i pull the Brake Lever, the brakes close as normal, but are then stuck to the rim !
    if i tighten the cable , the blocks are too close to the rim, And if i loosen the cable ,as soon as i pull the brake the blocks get pinned to the rim anyway !!!!!!!!
    :/ Sean kelly Tour on sunday !!!!!!!!
    247469249_2017413731748359_7675802031635703098_n.jpg

    "Bright lights and Thunder .................... "



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    #5
    coastwatch
    Registered Users Posts: 908 ✭✭✭coastwatch


    Sounds like the inner cable (wire) is not running freely, maybe frayed or rusted. They are about €5 a pair, in your lbs or halfords, and easy to replace.


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    #6
    Julius Seizure
    Closed Accounts Posts: 459 ✭✭Julius Seizure


    Bleh happened to a bike I got from halfords. On disk brakes. Must have been returned three times... never fixed. Then the guy who was fixing it lost his job when the others found out he wasn't qualified to work on brakes. Seemed very thin-lipped about it all. So the chief mechanic took it in but still no bacon :mad:


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    #7
    greenspurs
    Registered Users Posts: 10,218 ✭✭✭✭greenspurs


    i think i have it sorted !!
    on the right hand side of the caliper there is a 4mm nut, i loosened that and Voila... My brakes open and close correctly !!! :D
    Now onto the next problem...... Tuning gears... I cant get 1st gear !!!!!
    i have f**ked around with the screws on the rear derailer, but still cant get 1st gear !!! :eek:
    Thank you Carrera and Halfords !! :rolleyes:
    247469249_2017413731748359_7675802031635703098_n.jpg

    "Bright lights and Thunder .................... "



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    #8
    Icyseanfitz
    Registered Users Posts: 7,409 ✭✭✭Icyseanfitz


    first gear as in smallest cog in the back? you try loosing the cable tension?


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    #9
    greenspurs
    Registered Users Posts: 10,218 ✭✭✭✭greenspurs


    no, the Largest cog, nearest the wheel...
    I am turning the adjusting screw, but it still wont allow the derailer to select 1st (nearest the wheel), i have the screw out as far as it can go, and it still wont select 1st.....
    247469249_2017413731748359_7675802031635703098_n.jpg

    "Bright lights and Thunder .................... "



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    #10
    doozerie
    Registered Users Posts: 4,830 ✭✭✭doozerie


    I'm not sure which nut you are referring to, but something else to watch out for is if the brake pads were not lined up properly with the wheel rim then over time you may have ended up with most of each brake pad worn down but with a raised a lip of brake pad which was below the rim wall and never got worn down. This can lead to the brake pads "grabbing" the rim when you pull the brakes and not letting go - if you were pedaling the bike at the time the rotation of the rim would typically be enough to free the brake pads and he caliper would open but if you applied the brakes when the bike was stationary you might find the calipers holding their grip on the rim.


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    #11
    doozerie
    Registered Users Posts: 4,830 ✭✭✭doozerie


    Re gear changing, pull on the gear cable with your hand to see if you can get the derailleur into first gear. If not then try pushing the derailleur in by hand. If the derailleur doesn't budge then something is blocking it, either a limit screw or something as subtle as the jockey wheels being too close to the cassette (though I'd expect you to see/hear other problems if that were the issue).


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    #12
    Icyseanfitz
    Registered Users Posts: 7,409 ✭✭✭Icyseanfitz


    be very careful messing about with the low limit screw on a rear derailleur if you dont know what your at as you can end up sending your derailleur into the wheel,
    you said you have the screw all the way out, you shoudnt need to have it like that, can you push the derailleur up onto the cog with you thumb? or just pull the cable hard to put it into the cog, the top jockey wheel should be in line with the cog thats what the limit screw is for

    Only adjust the low limit when you have the front in the smallest cog and vice a verse with the high


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    #13
    Icyseanfitz
    Registered Users Posts: 7,409 ✭✭✭Icyseanfitz


    doozerie wrote: »
    Re gear changing, pull on the gear cable with your hand to see if you can get the derailleur into first gear. If not then try pushing the derailleur in by hand. If the derailleur doesn't budge then something is blocking it, either a limit screw or something as subtle as the jockey wheels being too close to the cassette (though I'd expect you to see/hear other problems if that were the issue).

    beat me to it :pac:


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    #14
    greenspurs
    Registered Users Posts: 10,218 ✭✭✭✭greenspurs


    cant move it in by hand...
    i have the limit screw out to the very end, and it still wont select 1st ! WTF am i missing !!
    247469249_2017413731748359_7675802031635703098_n.jpg

    "Bright lights and Thunder .................... "



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    #15
    Icyseanfitz
    Registered Users Posts: 7,409 ✭✭✭Icyseanfitz


    select your highest gear and remove the cable, see if you can push it up into gear without the cable


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    #16
    rich.d.berry
    Registered Users Posts: 517 ✭✭✭rich.d.berry


    Perhaps the derailleur hanger is bent.


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    #17
    kenmc
    Registered Users Posts: 7,276 ✭✭✭kenmc


    maybe you have an 8speed shifter and a 9 speed block (or 9 and 10)


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    #18
    greenspurs
    Registered Users Posts: 10,218 ✭✭✭✭greenspurs


    thanks for the advice lads..... Too late to try "fix" it now.... I have the brakes and gears working somehow, so hopefully they will last the Sean Kelly Tour tomorrow..... hopefully :)
    247469249_2017413731748359_7675802031635703098_n.jpg

    "Bright lights and Thunder .................... "



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