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Worth a Bleed?

Gilesw2010Gilesw2010 Posts: 121
edited June 2010 in MTB workshop & tech
Hi all - I just have a quick question about bleeding brakes. Hopefully you can help.

I bought a commencal Meta last month. Its a 2009 model fitted with Formula Oro K24's.

Now the power with the K24's isn't bad as such, but at the moment hardly mind blowing, as the reviews Ive read have suggested. As a comparison, the Formula RX's I have on my Cube are noticably better, as is the general lever feel.

On the commencal the levers don't exactly feel especially spongy, but certainly not as firm as the RX's. I definately have to squeeze the levers more to get to a similar level of power. I'm wondering if they could possibly benefit from a bleed? Although I bought the bike as 'new' its worth bearing in mind that given its model year it may well have been sat in a warehouse or on the shop floor for up to 18 months.

Do you think it would be worth getting them bled? I'm fairly new to this so I would be grateful of any help.

thanks in advance

Posts

  • nicklousenicklouse Posts: 50,675 Lives Here
    get the pads bedded in first and make sure the rotor is not being moved by the pads.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • Gilesw2010Gilesw2010 Posts: 121
    ah - now you may be onto something there Nick. Particularly in the rear brake one of the pads is definately closer to the rotor than the other. I have tried adjusting the caliper but the tolerances between pad and rotor are so small its almost impossible to get them centred perfectly.

    could it be that theres to much fluid in the system and therefore the pistons cant retract enough?
  • Gilesw2010Gilesw2010 Posts: 121
    does anyone on here have experience with these brakes? I think I'm going to get them bled and see how that helps. They really aren't seeming to be that powerful at all. It's barely possible to lock the back wheel up at the moment.

    I'd be interested to hear the views of anyone on here who has used or uses K24's Are they generally as good as the reviews have made out?
  • nicklousenicklouse Posts: 50,675 Lives Here
    yes lots of experience of them.

    so how does the lever feel?

    are the rotors being moved?

    and it is not impossible to get then centered.

    just push the pistons home and set the caliper again.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • Gilesw2010Gilesw2010 Posts: 121
    Hi Nick:

    The rotors feel a little more flexy than my RX levers on the Cube. Not drastically so, but theres definately a slight difference.

    its difficult to centre the rotors - I tried last night, but I did notice that when I push the pistons back in, one of them pops out slightly again, - by a mm or so, so is impossible to get flush up against the caliper body. Too much fluid in the system?

    Could this cause a loss of power?
  • nicklousenicklouse Posts: 50,675 Lives Here
    not the loss of power. but if when you push the second piston home the first one pops back out then yes too much fluid. can be easily sorted buy making the lever horizontal and removing the bleed screw. make sure you have a means of catching the fluid as it will be dripping from just above the front rotor.

    remember that after every movement of the caliper you will need to let the pads bed in again.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • Gilesw2010Gilesw2010 Posts: 121
    that great Nick, thanks. I'll give it a try.
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