Help with brakes!... (not symmetrical)

craig9045
craig9045 Posts: 4
edited November 2012 in MTB workshop & tech
Hi guys, im fairly new to cycling and very inexperienced when it comes to it going wrong!

Got a question you hopefully might be able to help me with, i was swapping my back brake pads to the front(long story) and after i put it back the front brake wasnt aligned straight. I've tried googling it and no matter what screws/bolts i tighten or loosen the pad touches one side and not on the other.

Because im clueless i don't know if its something simple or if someone who knows what their doing needs to have a look for themselves. I've put a few photo's the the break underneath anyways.

PLEASE HELP!

http://i49.tinypic.com/v8os5c.jpg
http://i45.tinypic.com/rli07p.jpg
http://i45.tinypic.com/34rjacz.jpg

Craig

Comments

  • Chunkers1980
    Chunkers1980 Posts: 8,035
    reset the pistons.
  • craig9045
    craig9045 Posts: 4
    hi thanks for your rely, im looking u exactly how to do that at the moment.

    I've noticed that its just one of the arm brackets (the one with the wire clamp) that doesnt seem to be moving when at all.
  • Chunkers1980
    Chunkers1980 Posts: 8,035
    Whoops. You've not got hydros!!

    You need to equalise the spring tension pulling each arm apart.
  • alfablue
    alfablue Posts: 8,497
    Firstly, make sure your wheel is straight in the dropout (do up the quick release with the bike on its wheel, if you do it with the bike upside down it is easier to misalign).

    Next, make sure each of the springs (long straight bit behind each caliper) is located behind the tab.

    There is a small cross-head screw on the outside of each brake caliper, if you screw the left one in, it will pull the brake out to the left, screw the right one in and it moves to the right. Unscrew either and the opposite happens. Adjust till centred.

    (also, there are concave / convex washers each side of the calliper on the brake pad fastening. Each side has a fat and a thin washer, make sure you have fat closest to wheel on both sides.

    Sometimes, old / tired / poorly maintained brakes will not return too well.

    Tuck the end of the cable behind the spring tab (or zip tie it there) as it will eventually snap / fray if left sticking out like that.
  • alfablue
    alfablue Posts: 8,497
    edited November 2012
    Chunkers1980 wrote:
    reset the pistons.
    he's got v brakes :roll: :wink:
  • alfablue
    alfablue Posts: 8,497
    This shows you what I said in detail, with pictures:

    http://www.parktool.com/blog/repair-hel ... brake-type
  • craig9045
    craig9045 Posts: 4
    Hi guys

    After a bit of fiddling ive got the brakes so they look straight. Just having a smaller issue where the rear of the left pad is touching and the front of it isnt. Not sure if this is something that i have done, theres a picture link underneath

    Thanks for all your help so far guys, really impressed at the speed of it!

    http://i45.tinypic.com/20p4qd3.jpg
  • zx6man
    zx6man Posts: 1,092
    Tiny comment, think you need to replace the pads anyway,,,,,
  • alfablue
    alfablue Posts: 8,497
    Looks to me like the concave convex washers are all in the wrong order. You need these to be right to set the pads at the right angle. (And yes, your pads are worn out to the point where you will start damaging your rims).

    This is the order they go in
    306-408.jpg
    Brake_Block_Parts.jpg

    (you may need the thick concave washer on the inside of the brake arm if your pads are very worn).
    Also, see this: http://en.wikibooks.org/wiki/Bicycles/M ... Rim_Brakes
  • alfablue
    alfablue Posts: 8,497
    Shimano's instructions are quite good, clear pics:

    http://techdocs.shimano.com/media/techd ... 604449.PDF

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