Cooked my disc?

M4rcus
M4rcus Posts: 33
edited May 2013 in MTB workshop & tech
Hi,

Whilst out on a ride tonight on my new Boardman Team FS I cooked the rear disc.... I was going down a short hill at the time and using the brake a bit... Leading up to the downhill the brakes were not used so I'm struggling to see why it cooked. One factor could be that I took the bike back to the shop not long after buying it as the rear brake did not much. I was told it was full of air...

The brake is working again, but I didn't try it on anything steep. The disc is blackened as you can see from the photo... Any ideas what might need to be changed or ideas as to why on such a short hill they cooked?

Cheers,

M

Comments

  • nicklouse
    nicklouse Posts: 50,675
    As metal gets hot it changes colour.

    Does it work fine?

    Then don worry.

    You will know when you boil the fluid.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
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  • levolon
    levolon Posts: 78
    heat tends to send em blue ,and they smell bloody hot too

    give em a clean and if ok dont worry "what pads have you got in the calipers?
  • M4rcus
    M4rcus Posts: 33
    Reading that back I probably didn't stress enough that the brake stopped working... That's when the fluid boils isn't it?

    Pads are stock, not sure, will look tomorrow.
  • stubs
    stubs Posts: 5,001
    Its your bikes way of telling you to stop dragging the brake.
    Fig rolls: proof that god loves cyclists and that she wants us to do another lap
  • cobba
    cobba Posts: 282
    M4rcus wrote:
    Reading that back I probably didn't stress enough that the brake stopped working... That's when the fluid boils isn't it?

    Pads are stock, not sure, will look tomorrow.

    Do some reading......

    http://www.hayesdiscbrake.com/hayes-u/
  • M4rcus
    M4rcus Posts: 33
    So more info... the 'hill' was only 0.3 miles long... should I really expect them to cook over such a short distance?
  • angry_bird
    angry_bird Posts: 3,786
    M4rcus wrote:
    So more info... the 'hill' was only 0.3 miles long... should I really expect them to cook over such a short distance?

    Depends how steep it was and how much you were braking, but potentially yes, I saw and smelt a shitload of brakes getting nice and hot last weekend on a descent that couldn't have been more than 300-400m long.
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  • cooldad
    cooldad Posts: 32,599
    For fun on the trails ask a newbie at the bottom of a trail whether their rotors are hot, then laugh when they get second degree burns.
    I don't do smileys.

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  • jairaj
    jairaj Posts: 3,009
    Can you try and describe better how the brakes are not working? Does the lever feel stiff when you pull on it? or is it spongy and moves all the way to the bars?

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