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  1. #1
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    BB7 185 vs.180mm. rotor

    New to the forums and I have a question that I couldn't find an answer to after searching.

    I have a 180mm Hope front rotor with Tektro brakes currently on the bike. I am looking to upgrade to BB7's in the front at least. I am not seeing 180mm rotors as an option with BB7's anywhere. Will I have to buy the 185, or will my 180 work? Will there be enough of a benefit to going up in size to the 185 to justify switching?....I'm not really opposed to it.

    Sorry if this has been answered already.

    Thanks.

  2. #2
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    You can use 180mm rotors on them, but you will not get full pad engagement on the rotor. With the BB there is quite a bit of pad to begin with, so I don't think there will be any issue. Personally I run 180mm adapters so that I can just shim the caliper out if I need to run 185mm rotor (not too often, but I do have a couple of avids laying around). Magura and shimano make 180mm adapters.

    Out of shear morbid curiousity, since you are buying mew brakes why not just get the complete setup with rotor/adapter from avid? Are you using the Hope with alloy carriers?
    Quote Originally Posted by saturnine
    that's the stupidest idea this side of pinkbike.

  3. #3
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    Quote Originally Posted by AL29er
    You can use 180mm rotors on them, but you will not get full pad engagement on the rotor. With the BB there is quite a bit of pad to begin with, so I don't think there will be any issue. Personally I run 180mm adapters so that I can just shim the caliper out if I need to run 185mm rotor (not too often, but I do have a couple of avids laying around). Magura and shimano make 180mm adapters.

    Out of shear morbid curiousity, since you are buying mew brakes why not just get the complete setup with rotor/adapter from avid? Are you using the Hope with alloy carriers?
    I am simply just trying to only buy what I need. No other reason. I can honestly say that I have no idea what alloy carriers are, but I don't have a hope caliper...only rotor.

  4. #4
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    Correct me if I am wrong, but if you buy a BB7 brakeset, the rotor comes with the kit

    I have never seen a BB7 brake sold separately

  5. #5
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    That could be the case. I've been googling all day, so my head is spinning.

  6. #6
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    I would use 185, when using a larger or smaller rotor the pads will either rub on the arms ( not good)or stick up above the rotor, resulting in eventually the pads touch each other and not the rotor and either way your not getting full stopping power

  7. #7
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    That makes sense dan0. Why upgrade if you're not getting the full effect. Is there anything I need to consider fitment wise before I buy?

  8. #8
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    Quote Originally Posted by AL29er
    You can use 180mm rotors on them, but you will not get full pad engagement on the rotor. With the BB there is quite a bit of pad to begin with, so I don't think there will be any issue. Personally I run 180mm adapters so that I can just shim the caliper out if I need to run 185mm rotor (not too often, but I do have a couple of avids laying around). Magura and shimano make 180mm adapters.

    Out of shear morbid curiousity, since you are buying mew brakes why not just get the complete setup with rotor/adapter from avid? Are you using the Hope with alloy carriers?
    There is an issue. If the pads hang off the outside of the rotor not all of the pad material wears down. The resulting "step" first rubs on the rotor edge and then the pads meet when worn enough and greatly reduces brake power
    mtbtires.com
    The trouble with common sense is it is no longer common

  9. #9
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    Quote Originally Posted by shiggy
    There is an issue. If the pads hang off the outside of the rotor not all of the pad material wears down. The resulting "step" first rubs on the rotor edge and then the pads meet when worn enough and greatly reduces brake power
    I dont believe it
    after all these years I finally beat shiggy to an answer

  10. #10
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    Quote Originally Posted by ninjammin
    That makes sense dan0. Why upgrade if you're not getting the full effect. Is there anything I need to consider fitment wise before I buy?
    pretty sure everything you need is in the kit, except levers and cables

    Avid BB7 Disc Brake

    Inboard/outboard adjustment knobs and a beefy two-piece forged body
    Precision ball bearing actuation and infinitely variable spring tension
    Tri-Align caliper positioning system aligns the caliper perfectly to the rotor with no trial and error and no pesky shims
    Tool-free pad adjustment
    Front and rear mounts included
    1 Mechanical Disc Brake
    Caliper and Rotor
    185mm G2 Rotor
    6 Bolt Mount, bolts included
    For use with Linear, V-Brake Levers
    Genuine Avid Pads pre-Installed
    Full Instruction Manual Included
    Levers and cables not included
    329 grams (caliper and 185mm rotor)

  11. #11
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    I should be able to keep my current lever and cable right? I can't imagine why not...obviously I'm new to the bike modification arena.

  12. #12
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    Quote Originally Posted by ninjammin
    I should be able to keep my current lever and cable right? I can't imagine why not...obviously I'm new to the bike modification arena.
    yes

  13. #13
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    Quote Originally Posted by ninjammin
    I should be able to keep my current lever and cable right? I can't imagine why not...obviously I'm new to the bike modification arena.
    you'll need new cables and housing.
    [SIZE=1][/SIZE]

  14. #14
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    To use your 180mm hope rotor.. You can use a 160mm rear caliper mount adapter on the front. I just did this to use a Formula 180mm rotor w/ my BB7s. Worked out perfect. All pads engage fully. It just sounds weird using a 160mm adapter to use a 180mm rotor.

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