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
  • Low stock - 2 items left
  • 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 depending on your location. 


    Effective Nov 19, 2021, for all online orders placed on or after Nov 19, 2021.

    Note: For all orders placed before November 19th.  Please see the old Policy here.

    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.

    All returns must be requested within sixty (60) days of the delivery date. All returned items must be received in new and unused condition, with the original tags and labels attached, and in the original packaging.  We cannot accept returns on any items that have been installed or show wear of any kind.  If you are unsure if your item qualifies for a return.  Please email us first:

    Return shipping charges will be paid for by the customer. 

    As a convenience, we can send you a pre-paid return label. The return shipping charge will be deducted from your refund when using our pre-paid label. Return shipping rates are as follows:  

    • Bicycles: Customer pays the quoted amount. Please contact us.
    • Oversized (Kuat racks etc.): $40 per box
    • Wheels: $20 per box
    • Medium packages: $10 per box/envelope
    • Small packages (Grips, brake pads, etc.): $5 box/envelope

    *Paid shipping charges will not be refunded.

    Return Process

    To return an item, please follow these steps:

    1. Email us at Please note the order number, the items that needed to be returned, and why.
    2. Once approved, we will notify you of the return label charge and email a pre-paid shipping label.
    3. Place the item in its original packaging, including all tags
    4. Pack the item securely to prevent any damage on its return trip.
    5. Drop the item off at your local post office.


    After receiving your return and inspecting the condition of your item, we will process your return. Please allow at least seven (7) days from the receipt of your item to process your return or exchange. Paid shipping charges will not be refunded. We will notify you by email when your return has been processed.

    For all Special Order items, there is a 25% restocking fee. Special Order items are those that we do not currently stock.


    We do not accept Exchanges. Instead, return the item as outlined above and place a new order for the item you would like to purchase. This will get the item into your hands weeks faster than an exchange would.


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

    Other questions?

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

    (928) 282-1106   |

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    Customer Reviews

    Based on 4 reviews
    Perfect for 203mm brake rotor

    This worked perfectly. Surprisingly confusing when researching brake adapters online. I got the SM-MA-F203P/PM, which is well described on this website. My fork is setup for 180mm rotors as well as my frame, used two of these adapters as I am running 203mm rotors front and rear. Worked perfectly.

    Angel Rodriguez

    Perfect service

    Awesome Online Store

    Fast shipping and Accurate product. Keep up the good service. Thank you.

    Frank Dionisio
    Great for converting from 140 to 160mm disc rotor

    Product performs as described on website. Used to convert from 140 to 160mm disc brake rotor. Installed easily with the included bolts/hardware. Delivered promptly. Will order from Thunder Mountain again!