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  1. #1
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    Avid mech that does not grab.

    Is this a common problem?

    The rear grabs very well and the lever feel is solid with good modulation, however the front disc does not feel the same. A hand full of front lever offers a weak no grab feel and begins to squeal when pressure is applied. The front caliper and rotor are brand new and I have set it up differently (3) times hoping to get better results.

    Any help would be appreciated. Thanks.

  2. #2
    "El Whatever"
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    Quote Originally Posted by top_ring
    Is this a common problem?

    The rear grabs very well and the lever feel is solid with good modulation, however the front disc does not feel the same. A hand full of front lever offers a weak no grab feel and begins to squeal when pressure is applied. The front caliper and rotor are brand new and I have set it up differently (3) times hoping to get better results.

    Any help would be appreciated. Thanks.
    Did you already bedded the pads in?? Seems like you haven't.
    Otherwise your rotor or pads can be contaminated with oil (or body oil if you/someone touched the rotor or pads barehands). Clean them with alcohol and go thru the bed in process again.
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  3. #3
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    hm..i had that problem recently. but my pads were trashed...

  4. #4
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    Pads are brand new...

    but I will attempt to clean them with alcohol, and scuff them up with sandpaper. Perhaps that will work?

  5. #5
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    Quote Originally Posted by top_ring
    but I will attempt to clean them with alcohol, and scuff them up with sandpaper. Perhaps that will work?
    Yeah, if you have new pads, then give it some time to bed in. I got some new pads for my avids and it took a couple rides before the power came back.
    Keep Pedaling

  6. #6
    "El Whatever"
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    Quote Originally Posted by top_ring
    but I will attempt to clean them with alcohol, and scuff them up with sandpaper. Perhaps that will work?
    Yup... find a not steep slope within a non traffic area and do some brake dragging stops from like 20mph to 0 (more less, is not rocket science). Do not sqeeze the levers or abuse your brakes. Treat them gently until you can feel they have their complete stopping power. Once bedded in you will be able to endo with just one finger.

    After any time you clean your pads you'll have to go thru the full bed-in process again. I don't understand why but after cleaning you loss power temporarly which cures after bed the pads in again.
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  7. #7
    Roy
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    Quote Originally Posted by top_ring
    but I will attempt to clean them with alcohol, and scuff them up with sandpaper. Perhaps that will work?
    Do NOT clean the pads with alcohol. Clean the rotor with alcohol and burn the pads in on long extended downhill braking. If this doesn't bed the pads in, it sounds like they are truly contaminated and there are various remedies for this:
    - torch them
    - boil them
    - bake them in an oven

    I've used the torch method with success in the past. Lots of old posts on how to do this.

  8. #8
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    Thanks all... good suggestions,

    but I fail to see why I have to do this in the first place. These pads and rotor and caliper are out of the box - brand new. I can`t believe that this is typical of a new Avid mech braking system?

    Although I`ve never had disc brakes before, and don`t really know what to expect, I`m beginning to think that for the extra weight, they aren`t worth a damn... and rim brakes are hassle free!

    If I have to, I`ll torch them... reluctantly.

  9. #9
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    Quote Originally Posted by top_ring
    but I fail to see why I have to do this in the first place. These pads and rotor and caliper are out of the box - brand new. I can`t believe that this is typical of a new Avid mech braking system?
    You have to do this with all disc brakes. Once they are broken in, you'll be greatfull for them.

  10. #10
    Roy
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    Quote Originally Posted by top_ring
    but I fail to see why I have to do this in the first place. These pads and rotor and caliper are out of the box - brand new. I can`t believe that this is typical of a new Avid mech braking system?

    Although I`ve never had disc brakes before, and don`t really know what to expect, I`m beginning to think that for the extra weight, they aren`t worth a damn... and rim brakes are hassle free!

    If I have to, I`ll torch them... reluctantly.
    This is only assuming they've been contaminated - as we are only theorizing. All new disc brakes need to be broken in first and if they still don't grab after being broken in, something is wrong: either they aren't set up quite right or something got on the pads. I've seen people spray on chain lube right by the disc caliper/rotor, completely clueless of the overspray.
    In your case, some extended downhill front only braking should be all you need. Plus, depending on your lever, crank up the power (Shimano and Avid levers have adjustable power).
    But whatever you do, do not put any chemicals on the pads (no brake cleaner, no alcohol, no nothing). If you have, then they are now contaminated and will require torching. Soap/water is it for the pads.

  11. #11
    "El Whatever"
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    Quote Originally Posted by Roy
    Do NOT clean the pads with alcohol. Clean the rotor with alcohol and burn the pads in on long extended downhill braking. If this doesn't bed the pads in, it sounds like they are truly contaminated and there are various remedies for this:
    - torch them
    - boil them
    - bake them in an oven

    I've used the torch method with success in the past. Lots of old posts on how to do this.
    DO NOT TORCH THEM OR BAKE THE PADS. We simply don't know how the pad material is bonded to the baking plate. The bonder would simply fail is it's affected by heat. The pads could also suffer graining or crumble gradually. It's just a possibility, but check out on the forum and you will find a thread of a guy who suffered from this after baking pads!!!!

    Believe me, you'd rather spend 25 bux on a new pair than fooling around with "touched" pads. Brakes is the only place on the bike where you will regret a failure for sure.
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  12. #12
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    I did not see this mentioned so I'll throw it out. The first time I used Avid Mechs, I had the same problem, the rear end locked up at the half pull, but the front was not strong enough. I found the 'fixed' pad on the caliper was to far away, the the 'moving' pad was having to bend the rotor to make contract with the other pad. This took away from the power. I also saw movement in the cable housing. I shortened the housing and zip tied it to the fork, the flex was gone. Between these two adjustments, the power in the front matched the rear.

  13. #13
    Roy
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    Quote Originally Posted by Warp2003
    DO NOT TORCH THEM OR BAKE THE PADS. We simply don't know how the pad material is bonded to the baking plate. The bonder would simply fail is it's affected by heat. The pads could also suffer graining or crumble gradually. It's just a possibility, but check out on the forum and you will find a thread of a guy who suffered from this after baking pads!!!!

    Believe me, you'd rather spend 25 bux on a new pair than fooling around with "touched" pads. Brakes is the only place on the bike where you will regret a failure for sure.

    Relax, take a deep breath, and go read the old board archives - people have been torching/baking/boiling pads for years with great success. You have to heat the chemical to the flash point and then you're fine.

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