Free 2-Day Shipping on Orders Over $50* – Limited Time Only

Detail Images

  • Shimano SM-MA90 Disc Brake Adapter Detail
  • Shimano SM-MA90 Disc Brake Adapter One Color
  • Shimano SM-MA90 Disc Brake Adapter Detail

Available colors

  • Shimano SM-MA90 Disc Brake Adapter One Color

Shimano SM-MA90 Disc Brake Adapter

$7.99 - $8.99

Free 2-Day shipping on orders over $50*

Select style & size:

Select options
  • Select options
    • One Color, Post, 180mm
    • One Color, Rear ISO, 160mm
    • One Color, Rear ISO, 180mm
    • One Color, P/P Front, 180mm to 203mm
    • One Color, Rear ISO, 140mm
    5.0 5 8

    8 Reviews


    With the SM-MA90 Disc Brake Adapter, Shimano has taken an artful leap at the lowly disc brake adapter. Not only is it lighter than their older adapters, but it's more refined -- this refinement being the reason for its lightness. Where Shimano's older adapters were blocky, this one has curved edges. Where they were solid, this one has a window machined out of the center of the adapter body.

    The Shimano SM-MA90 Disc Brake Adapter is available in five versions to fit 160 and 180mm rotors for front ISO or Post mounts and rear ISO mounts.

    • Item #SHI0547

    Tech Specs

    Shimano front ISO/Post and rear ISO
    Recommended Use
    getting calipers to fit correctly
    Manufacturer Warranty
    1 year

    Tech Specs

    • Reviews
    • Q & A

    What do you think about this product?

    Have questions about this product?

    gotta have it

    • Familiarity: I've used it several times

    My fat bike came with hydraulic 160mm rotors in front and back. For winter, I wanted mechanical brakes and figured I'd upsize the front. Need an adapter to accommodate the 180mm rotor. I used this even though installing TRP Spykes with an centerline rotor--it's all working well together.

    Upgrade to 180

      I recently installed new rotors on my Santa Cruz Tallboy LTC. After riding a friends bike which had 180mm rotors front and rear, I decided I'd do the same. It's made a noticeable difference for sure. I got the Post for the front and the ISO option for the rear. Just a heads up sometimes ISO is referred to as IS.

      Fits Avid brakes

      • Familiarity: I've put it through the wringer

      Bought this to install a Avid Elixir 9 Trail front caliper on a post to post mount using a 180 Rotor. Fits perfectly! Avid for some strange reason does not sell a 180mm adapter, but only provides them on complete bikes.

      Will this adapter work with shimano xt...

      Will this adapter work with shimano xt brakes on a Fox float RL fork (with post mount). Trying to put on a 180mm rotor but want to make sure i get the right adapter. Thanks.