Stuck trying to find a 185 adapter for 74mm post mounts- Mtbr.com
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  1. #1
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    Stuck trying to find a 185 adapter for 74mm post mounts

    I've been stumped over this one. I'm trying to fit my Avid Juicy 7's to a Fox Float 32 fork using a 185mm rotor. I pulled the 185mm adapter out of the box the brakes came in and it doesn't fit!



    It leaves that gap on the bottom bolt, it seems to me that I need one that is the same thickness on both ends, but I can't find any. I found that if I move all the spacers for the bottom bolt to the inside of the caliper it will fit, but I can't imagine it having been designed like that. Has anyone had this issue?

  2. #2
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    Try flipping the bracket top for bottom--thick end down.
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  3. #3
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    I don't see a wheel or hub in the picture, just the axle and a loose rotor so it is kind of hard to figure out what problem your having

    If the caliper in binding on the bolt, loosen the top bolt and tighten them at even intervals till the caliper is tightened down.

  4. #4
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    What mtnbiker72 said. Back that top bolt out a bunch and then alternately turn the bolts back in while holding the caliper and adapter against the posts. The orientation of your adapter is correct, thick side and the Avid logo always go up. But before you do I would suggest pulling that caliper and threading the bolt by itself into the lower mount to check the depth. Just to make sure there isn't an obstruction of some sort in there. Not likely, but it always pays to check.

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  5. #5
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    Quote Originally Posted by Squash
    What mtnbiker72 said. Back that top bolt out a bunch and then alternately turn the bolts back in while holding the caliper and adapter against the posts. The orientation of your adapter is correct, thick side and the Avid logo always go up. But before you do I would suggest pulling that caliper and threading the bolt by itself into the lower mount to check the depth. Just to make sure there isn't an obstruction of some sort in there. Not likely, but it always pays to check.

    Good Dirt
    Yes, both of the above are correct. You just bound up the caliper by putting the top bolt in all the way first.
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  6. #6
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    I revisited this last night. There is deffinately something wrong with this. If I try to do as described above (hold the caliper against the bracket and then put the bolts through) the bolts can not be pushed throught the slots in the caliper as well as the holes in the adapter. It is clear that they are at entirely different angles which binds them up. (hopefully that makes sense to everyone...) I'm wondering if this fork is set up to be specificly for 160mm or 203 mm rotors. Has anyone heard of this? The only other explanation is that my adapter has been incorrectly made.

  7. #7
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    Quote Originally Posted by Towny
    I revisited this last night. There is deffinately something wrong with this. If I try to do as described above (hold the caliper against the bracket and then put the bolts through) the bolts can not be pushed throught the slots in the caliper as well as the holes in the adapter. It is clear that they are at entirely different angles which binds them up. (hopefully that makes sense to everyone...) I'm wondering if this fork is set up to be specificly for 160mm or 203 mm rotors. Has anyone heard of this? The only other explanation is that my adapter has been incorrectly made.
    IIRC my BB7 slots have a bit of wiggle room in them (necessary for the CPS washer stack to work). I would take a round file and put a bevel on the inside of caliper slots (or the bracket holes if you prefer).

    My BB7 with the extruded bracket on a Reba looks like this.
    Stuck trying to find a 185 adapter for 74mm post mounts-avid185.jpg
    Note that the caliper is at a slight angle relative to the bracket.
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  8. #8
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    Yeah I see that angle in there. That's deffinately the problem, just not enough clearance... Damn you Avid for making me grind on your outrageously overpriced brakes!

  9. #9
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    Quote Originally Posted by Towny
    Yeah I see that angle in there. That's deffinately the problem, just not enough clearance... Damn you Avid for making me grind on your outrageously overpriced brakes!
    Should only take a few strokes with a chainsaw file to fix it.
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  10. #10
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    One bolt is supposed to be longer than the other, usually the longer one goes up, but try reversing them as the Fox lower tab is very shallow.
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  11. #11
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    I ended up putting the mounting bolts into my drill press and hitting them with a file to take the threads off of the upper part of the bolt in order to get the clearance I needed. The caliper fit right on after I did that.



    I just didn't have the guts to take the dremel to my brakes!

  12. #12
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    Quote Originally Posted by Towny
    I ended up putting the mounting bolts into my drill press and hitting them with a file to take the threads off of the upper part of the bolt in order to get the clearance I needed. The caliper fit right on after I did that.



    I just didn't have the guts to take the dremel to my brakes!
    I would rather (and have) remove a minor non structural amount from the caliper (with a hand file) than grind on the part holding everything together.
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  13. #13
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    I think it's ok, the bolt was just too long... so it was grinding, cutting or getting a new bolt.
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  14. #14
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    Quote Originally Posted by Relayden
    I think it's ok, the bolt was just too long... so it was grinding, cutting or getting a new bolt.
    I think you are reading the wrong thread.
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  15. #15
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    lol, let me check... no I'm sober...
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  16. #16
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    Quote Originally Posted by Relayden
    lol, let me check... no I'm sober...
    Well, your replies do not work in this one.

    Quote Originally Posted by Relayden
    One bolt is supposed to be longer than the other, usually the longer one goes up, but try reversing them as the Fox lower tab is very shallow.
    does not help to put the longer bolt on the shallower hole.


    Quote Originally Posted by Relayden
    I think it's ok, the bolt was just too long... so it was grinding, cutting or getting a new bolt..
    he did not change the overall length of the bolts.
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  17. #17
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    ok, now I'm confused...haha... hold on, is this the Stuck trying to find a 185mm..... thread? Ok now I see what he did.... Good job, I didn't noticed the grinding...odd, I've never had a problems like that with that combo Fox-Avid.
    Last edited by Relayden; 05-04-2011 at 08:21 AM.
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  18. #18
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    Quote Originally Posted by shiggy
    I would rather (and have) remove a minor non structural amount from the caliper (with a hand file) than grind on the part holding everything together.
    I figured this would alarm some people! Im thinking since I didn't file any deeper than the root diameter of the threads, the majority of the meat that bolt had is still there. I'm not to concerned with it being weakened (especially since this size bolt has such a low torque the stretch on it isn't going to be much). I'll let everyone know if I have a catastrophic failure. (Or if I never post on this forum again you can probably assume...)

  19. #19
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    I dont get it. How come you're the only one having this problem. I have the same adapter for 185mm disc and never had a problem. If you put everything on the bolts (caliper, washer, etc) before threading it on the post mount, you would not get this problem!

  20. #20
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    Quote Originally Posted by edispilf
    I dont get it. How come you're the only one having this problem. I have the same adapter for 185mm disc and never had a problem. If you put everything on the bolts (caliper, washer, etc) before threading it on the post mount, you would not get this problem!
    I would bet on a little extra paint in the caliper slots.
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  21. #21
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    Yeah, I don't know but I did try every possible combo to get them to fit first! Looking at the bolts in the caliper slots, there was no extra wiggle room there. The diameter of the bolt was the same size as the width of the slot. Im not sure if something was out of tolerance or not. I did take the bike out yesterday and rode about 25 miles without any issues with this.

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