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I have to really pull my rear brake for it to have an effect

DJLad97DJLad97 Posts: 2
edited May 2018 in MTB workshop & tech
And when I do get the point where it starts breaking, the force is quite minimal and the brakes start squealing.
(My bike is the canyon spectral al 6.0 2016)
When I took my bike for a regular service, I brought up this issue and he replaced the brake pads. (I'm not sure if bled the brakes, my parents picked it up and obviously they weren't 100% on everything he said)
I have noticed that there is a lot more movement in my rear brakes compared to the front ones. See: https://www.youtube.com/watch?v=V_fyghzUQww
I'm not sure if this means anything but thought I might as well mention it.
There is also a possibility that they could be contaminated with bike cleaner (muc off). But I feel my ignorance would have also meant I contaminated my front ones - which I haven't.

I know it's unlikely to exactly diagnose what's wrong, but any advice is appreciated :)

Thanks
-Dan

Posts

  • dcwhite1984dcwhite1984 Posts: 86
    Worth giving the discs a proper clean with disc brake cleaner.
    Sounds to me like you may need to bleed the rear brake or add a little fluid.
    Do you have adjustable brake levers?

    Alternatively give the bike shop a ring, if they have changed the pads they should have checked that they were okay before handing the bike back, they should be willing to take it back in and have a look at least.
  • figbatfigbat Posts: 680
    Movement could be from an off-centred caliper or a sticky piston. The first is easy enough to fix (loosen the mounting bolts, pull the brake, tighten the bolts with the brake still applied - then check that the disc runs centrally down the caliper opening. The latter requires the caliper to be cleaned and potentially overhauled.

    New pads can take a little bit of running in - a few hard stops from speed ought to do it (without locking the wheel).

    How far does the lever move before it stops? If it pulls back to the bar, or near it, then you may need to bleed and/or add more fluid. If this hasn't been done for a while, it is worth doing anyway. It is unlikely the brakes were bled unless specifically asked for or stated as part of the service. Replacing pads does not generally include bleeding the brakes.
    Cube Reaction GTC Pro 29 for the lumpy stuff
    Cannondale Synapse alloy with 'guards for the winter roads
    Fuji Altamira 2.7 for the summer roads
    Trek 830 Mountain Track frame turned into a gravel bike - for anywhere & everywhere
  • steelosteelo Posts: 541
    edited May 2018
    You should have an adjuster on the lever, give it a few turns either way to see if it has an effect on where the 'bite' point of the brake is. Also, If you have new pads then they will need to bed in so just accept they may be a little spongy for a bit while the surface of the pad burns off, you can cheat it a bit by rubbing the surface of the pads with fine grit sandpaper but it's better to just get out and ride and let them bed in on a few long downhill runs with the brakes applied.

    The rear brake is over-rated anyway, just use the front!
    Specialized Rockhopper '07
    Trek Fuel EX8 '09
  • JBAJBA Posts: 2,707
    steelo wrote:
    let them bed in on a few long downhill runs with the brakes gently applied.

    That sounds like a good way to glaze the pads.
    “Life has been unfaithful
    And it all promised so so much”

    Giant Trance 2 27.5 2016 ¦ Sonder Broken Road 2021¦ Bird Zero Mk1 ¦ Giant Revolt Advanced 2 2019 ¦ Giant Anthem 3 2015 ¦ Specialized Myka Comp FSR 2009
  • steelosteelo Posts: 541
    I've heard of glazed doughnuts but not glazed pads, is that a new thing all the kids are talking about these days?
    Specialized Rockhopper '07
    Trek Fuel EX8 '09
  • swod1swod1 Posts: 1,639
    steelo wrote:
    I've heard of glazed doughnuts but not glazed pads, is that a new thing all the kids are talking about these days?

    Well you'll find out if you drag your brakes on rides, they wont work as well and you'll probably get some squeal from them.
  • 3wheeler3wheeler Posts: 110
    Probably easiest to take it back to the shop to get them to look at it again, or at least explain what they thought the problem was if it was more than just a case of needing new pads.
  • steelosteelo Posts: 541
    Some people just don't get good honest sarcasm these days. Maybe sarcasm isn't cool anymore like it was in my day!
    Try reading this, can't remember where I saw it, but I know it has a tendancy to work sometimes, depending on how much glazing you have, and I don't mean number of windows!

    https://www.bikeradar.com/gear/article/ ... ads-31337/
    Specialized Rockhopper '07
    Trek Fuel EX8 '09
  • JBAJBA Posts: 2,707
    "drag the brake for five or six seconds to build heat and then increase lever pressure until the bike stops. Six or seven runs should bring a good improvement."

    Not the same as a few long downhill runs with the brakes gently applied though, is it?

    (Your ninja editing skills aren't too good either :wink:)

    Anyway, I didn't intend to start a row or upset anyone so let's just move on...
    “Life has been unfaithful
    And it all promised so so much”

    Giant Trance 2 27.5 2016 ¦ Sonder Broken Road 2021¦ Bird Zero Mk1 ¦ Giant Revolt Advanced 2 2019 ¦ Giant Anthem 3 2015 ¦ Specialized Myka Comp FSR 2009
  • steelosteelo Posts: 541
    My ninja editing skills as you so expertly typed have hopefully made sure no-one else reads my incorrect response and 'glazes' their pads - dumbass
    I added the link to ensure I could be as helpful as possible.
    Clearly there are a few keyboard warriors on here with too much time on their hands.
    Specialized Rockhopper '07
    Trek Fuel EX8 '09
  • steelosteelo Posts: 541
    Thanks
    Specialized Rockhopper '07
    Trek Fuel EX8 '09
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