Shimano Disc Brake Adapter - Thunder Mountain Bikes
Shimano Disc Brake Adapter - Thunder Mountain Bikes
Shimano Disc Brake Adapter - Thunder Mountain Bikes
Disc Brake Adapter (Shimano)

Disc Brake Adapter (Shimano)


Regular price $10.99 Sale price$8.99
  • In stock, ready to ship
  • Inventory on the way
  • Free shipping on all orders $49+

Shimano post mount disc brake adapters allow you to run your preferred rotor size.


  • Material: Aluminum
  • Mounting hardware included

Model No: SM-MA-F180P/P2

  • Size: +20mm
  • Lifts your brake caliper 20mm
  • Example: 180mm post mount fork,  200mm rotor

Model No: SM-MA-F203P/PM

  • Size: +23mm
  • Lifts your brake caliper 23mm
  • Example: 180mm post mount fork,  203mm rotor

Model No: SM-MA-F220P/PM

  • Size: +40mm
  • Lifts your brake caliper 40mm
  • Example: 180mm post mount fork,  220mm rotor

Model No: SM-MA-F203P/P

  • Size: +43mm
  • Lifts your brake caliper 43mm
  • Example: 160mm post mount fork,  203mm rotor


  • Standard post mount brake calipers
  • Post mount forks

    Please reach out to us with any questions you may have on anything we sell. We want to make sure you get the right part the first time. Our lifelong riders at Thunder Mountain Bikes are knowledgeable and would love to talk to you!


    We currently offer both economy and expedited shipping options though FedEX and USPS. 

    Orders totaling over $49 are eligible to ship for free via an economy ground option of our choice. 

    If you're in need of something super-quick, please contact us directly. We may be able to overnight your order with an additional fee and depending on your location. 


    Should there be an issue with the item you bought, or you no longer need your purchase, we will be happy to set up a return.

    Returns or exchange requests for New or Used Bikes must be requested by emailing us at within fifteen (15) days from the date of delivery. Bikes must be in un-ridden condition. Custom-built bikes may not be returned. Returned bikes have a $200 restocking fee and the customer pays for return shipping.

    Returns for most other items may be requested within sixty (60) days of the delivery date. All returned items must be received in new, unused, and uninstalled condition, with the original tags and labels attached and in the original packaging. We cannot accept returns on any items installed or show wear of any kind. 

    Clearance and open-box items may not be returned. 


    To request a return, please log in to your customer account by clicking the  customer account icon  Profile icon in the top right of any page or visit

    1. In the Email field, enter your email address and click Continue.

    2. In your email account, open the email sent from our store and copy the six-digit verification code included in the email.

    3. Go back to the online store and enter a six-digit verification code to log in.

    4. Find and click on the order that you want to submit a return for.

    5. If your order has more than one item, select only the items you want to return.

    6. Select a return reason and add a note for the store if needed.

    7. Click Request Return.

    Once your return request is approved, you will receive an email with shipping instructions and a return shipping label. 


    We will process your return after we receive your returned item(s) and inspect the condition. Please allow at least seven (7) days from the receipt of your item to process your refund. We will notify you by email when your return has been processed.


    If you receive defective or damaged products or if we sent you the wrong products, please contact us using the phone number or email below.


    If you have any questions concerning our return policy, please contact us at:

    (928) 282-1106   |

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    Customer Reviews

    Based on 9 reviews
    Useful for what they are

    Love these guys have a detailed explanation of the description. Made it easy to choose the right parts. Thank you TMB


    Part worked perfectly. Increased rotor size and good to go. Super fast shipping.

    Jay Minasi
    ian rocks

    this part works. no directions but even i figured it out. be sure to use blue loctite on the bolts or your brakes can and will suddenly go out of true and freak you out with a bad noise. Under NO circumstances use Red loctite.

    Giovanni Sclarandis
    Works as it should

    Very simple to install. Even has the blue thread locker on the included bolts. Just make sure you have enough slack in your brake line to get the angle right.

    Damian R
    40mm disc brake adapter

    It is what it is. Nothing more and nothing less. However, this shop always has a good stock of parts and very quick turnaround time from the time of purchase to it getting to your door. This is my local online shop when local bike shops don't have what I need.