Are these 160mm to 180mm post adapters safe to use?- Mtbr.com
Results 1 to 6 of 6
  1. #1
    mtbr member
    Reputation:
    Join Date
    Nov 2008
    Posts
    212

    Are these 160mm to 180mm post adapters safe to use?

    I'm facing a problem that seems to be rather familiar: I have Avid BBDB Type N (basically BB7) brakes on a post mount fork and I want to switch the front rotor from 160mm to 180mm. Avid's rotors and adapters are 185mm but for some reason they are way more expensive than all the other brands out there, so that's why I'm looking at 180mm.

    I've read that one option is to get a 185mm adapter and shave it down. Another is to use another manufacturer's 180mm adapters. A third option which I think works only for IS mounts is to use a 160mm rear adapter on the front to achieve 180mm spacing.

    However, I did find some very simple adapters on the ComCycle USA online store. They are for post mount 160mm to 180mm and will work with any caliper, simply because they are a pair of bolts with spacers. Here they are:
    Name:  Picture.aspx.jpeg
Views: 739
Size:  4.5 KB

    My biggest concern is, are these adapters safe to use? Compare to Avid's adapter:


    That brace between the two bolts holes isn't just there for show, it's there to brace the mounting bolts against lateral forces which could try to shear or bend the bolts. Which leads me to wonder, why would ComCycle even sell an adapter when it seems like it is much weaker?

    A related question: would this adapter work with with Avid brake calipers?

    Last edited by derailin_palin; 11-11-2009 at 03:09 PM.

  2. #2
    Off the back...
    Reputation: pinkrobe's Avatar
    Join Date
    Jan 2004
    Posts
    2,121
    The second one [ebay] looks just like the Shimano unit. It looks good to me...
    @pinkrobeyyc
    #pinkrobeyyc

  3. #3
    mtbr member
    Reputation:
    Join Date
    Nov 2008
    Posts
    212
    Quote Originally Posted by pinkrobe
    The second one [ebay] looks just like the Shimano unit. It looks good to me...
    You mean this one right?

    It looks good to me, too, but will it actually fit an Avid BB7 or BBDB-N caliper without any clearance issues?

  4. #4
    mtbr member
    Reputation: Aresab's Avatar
    Join Date
    Mar 2007
    Posts
    1,658
    I've used all 3 adapters, the first work ok, but you might have to file some material down. You can see the 2 below have different heights for each screw. Also, what rotors are you running? The 7" from Avis are 185's and Shimano/Hayes/... use 180. So, you might have to use a washer or 2 to get the right height.

  5. #5
    mtbr member
    Reputation: jearl's Avatar
    Join Date
    Jul 2012
    Posts
    209
    I know it has been a while since this post was active, but I have a question about these adapters. I just purchased a 2013 Stump Jumper FSR Comp 29. The front rotor is 180mm with the post adapters seen in the first picture. I am getting a wobble in the front tire only while braking with the front brake. The wheel and rotor both appear to be true. Is it possible that those adapters are the reason for the wobble ( not stiff enough ), and I should look at purchasing one of the post adapters seen in the second photo to give more support while braking? Or is it just the characteristics of the Avid brakes? I am around 220 with all my gear on.
    "Ideal bikes are not bought, they evolve beneath you"

  6. #6
    Happy Trails
    Reputation: Scott In MD's Avatar
    Join Date
    Sep 2008
    Posts
    1,174

    Are these 160mm to 180mm post adapters safe to use?

    I up-sized rotors on my hard tail and full suspension with good results. If you are using the OEM stock set up, from reputable supplier and LBS, you should be good. But worth your time to take the bike by LBS and ask them to check out the torque on your calipers mounting Allen-head bolts and the six rotor mounting Torx screws.

Members who have read this thread: 0

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

THE SITE

ABOUT MTBR

VISIT US AT

© Copyright 2019 VerticalScope Inc. All rights reserved.