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Shimano Disc Brake Adapters
Sale $5.98 - $11.95

Item # SHI0108

Select options
  • Select options
  • SM-MA-R160, IS/Post Rear ($8.00)
  • SM-MA-R180, IS/Post Rear ($8.00)
  • SM-MA-R203, IS/Post Rear ($8.00)
  • SM-MA-F160, IS/Post Front ($8.00)
  • SM-MA-F180, IS/Post Front ($8.00)
  • SM-MA-F203 (160mm to 203mm), IS/Post Front ($8.00)
  • SM-MA-F180, Post/Post Front/Rear ($5.98)
  • SM-MA-F203 (160mm to 203mm), Post/Post Front/Rear ($8.00)
  • SM-MA-F180, IS/IS Front ($11.95)
  • SM-MA-F203 (180mm to 203mm), Post/Post Front/Rear ($7.99)
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Item # SHI0108



Like much of life, making your Shimano disc brakes work with your 160mm rotor is easy --once you learn how to figure out which adapter you need. Whatever you have, we can either sell you the adapters to make it work, or tell you that what you have is enough.

You need to know three things -- what kind of mount your Shimano disc caliper is, International Standard (ISO) or post mount. If it goes on the front, you need to know what your fork is: ISO, post-mount, or a few special cases (Marzocchi 20mm axle, Boxxer-type). And, you need to know the rotor size that you're trying to fit -- in this case, it's 160mm.

If you're trying to diagnose what you already have and/or what you need, here's how to do it. The Shimano adapters all have a model number that starts with SM. The Mount Adapter acronym is MA. Front brake is F. Rear brake is R. Rotor Size is 160, 180, or 203. Caliper Mount Type will be S for ISO/International A, and P will represent Post. And the last letter will be for the frame or fork mount type: S for ISO/A, P for Post, B for Boxxer, Z for Marzocchi 20mm Axle as well as QR20Plus and DH ISO. Thus an adapter that reads SM-MA-F-203S/P is Shimano Small Parts Mount Adapter Front 203mm Rotor with ISO caliper on a Post type fork.

  • Durable alloy construction
  • Mounting hardware included
  • Compatible with ISO and post-mount calipers and frames/forks

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  • Familiarity: I've put it through the wringer

Easy to use and a good option for upgrading your rotors to a larger diameter

Avg. ride time: 4m per week
  • Average ride time is based on Strava activity over the last 3 months. Give your reviews credibility by connecting your account.


  • Familiarity: I've put it through the wringer

i love running bigger rotors so In return I love that this lets me run them! never had an issue with these!

It Works

  • Familiarity: I've put it through the wringer

If you are using Shimano brakes this is a must have. Super easy to match up what you need.

Gotta have it

  • Familiarity: I've put it through the wringer

You gotta have adapters if running a larger rotor. The Shimano adapters do the trick.

It works

  • Familiarity: I've used it several times

Comes with everything you need to increase stopping power. Easy to install with clear instructions included.

Worked perfectly on a Giant Trance 2

    I bought two of these adapters for my Trance 2 and they worked great. You use the same adapter for the front and the rear. The arrow on the front faces up and on the rear the arrow faces forward. I went from a 180 mm rotor to the 203 mm rotor, front and rear. I used the Shimano RT-86 ice tech rotors (XT 6 bolt style). I am very pleased with the performance and braking power it gave me. The only thing that is confusing is the photo shown. The photo shows the IS/Post but the description shows the correct one for Post/Post

    Part is great. Shipping was overpriced.

    • Familiarity: I've used it several times

    Part is great and have no qualms about it. However, I paid for overnight shipping, and it came in three days. That really is bs when you pay an extra 20 bucks for shipping and it still doesn't come when you need it. very disappointing.

    I want to put a 203mm rotor on a rock shox pike using SRAM guide RSC brakes. What is the model of adapter I need.



    I'm not sure, but this unit is for Shimano brakes.

    Fit like a glove

    • Familiarity: I've used it several times

    The letter f will fit rear for p/p 180, if you are wondering. Needed an adaptor p/p on front and rear on my Niner jet 9 and was searching for letter designation for rear for 180mm p/p adaptor. Anyway fit like a glove. Love competitive cyclist, but you guys are going to have to step your game up in the shipping department. Way to slow!

    Yeti SB6

    • Familiarity: I've put it through the wringer

    Works on my 2016 Yeti SB6 with Fox 36 fork. Running 180 rotors front and rear. Bought 2 - SM-MA-F180, Post/Post Front/Rear. Running guide brakes.

    Unanswered Question

    i have a 2017 yeti sb6 and sram guide rs brakes with 180mm rear rotors now, is this the brake adaptor i need to use sram's centerline 200mm rotors in the rear? there's currently an adaptor installed

    Works great

    • Familiarity: I've put it through the wringer

    Tolerances are good, work great, and come with all the hardware you need. What more do you need?

    Purchased for my custom build on an SB6

      Purchased for my custom build on a new Yeti SB 6, worked out perfectly!

      Gets the Job Done, Nothing Flashy

      • Familiarity: I've put it through the wringer

      It is a brake adapter, if it allows my brakes to function properly without rub it is a 5 star in my book.

      Make your rotors fit your frame

        This simple piece of metal makes it possible for you to reach unprecedented speeds biking, and come back alive. simply select the version you need, attach it to your frame and caliper, and magically when you squeeze the lever on your bar, you will begin to slow down. Amazing.

        go big, go bigger

        • Familiarity: I've put it through the wringer

        Built a Jones bike recently and JeffJ advocates 203mm rotors up front, 180mm in back. Needed the appropriate adapters to get the discs around those big rotors. Mounted quickly, adjusted appropriately. Worked perfect.