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Shimano Disc Brake Adapters

up to 55% Off
sale $7.15 - $15.99

Select Style & Size

  • SM-MA-R160, IS/Post Rear
    sale $8.00
  • SM-MA-R180, IS/Post Rear
    $10.99
  • SM-MA-F180P, Plus 20mm Post Mount
    $9.99
  • SM-MA-F203P, Plus 23mm Post Mount
    $9.99
  • SM-MA-R203, IS/Post Rear
    $10.99
  • SM-MA-F160, IS/Post Front
    sale $8.00
  • SM-MA-F180, IS/Post Front
    $10.99
  • SM-MA-F203 (160mm to 203mm), IS/Post Front
    sale $8.00
  • SM-MA-F203 (160mm to 203mm), Post/Post Front/Rear
    sale $8.00
  • SM-MA-F180, IS/IS Front
    sale $7.15

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77 Reviews

Disc Brake Adapters

Whether you're trying to mount your 160mm rotor with an ISO or post-mount setup, we've got the right Shimano Disc Brake Adapters for the job. All you need is the skeleton key to understanding Shimano's admittedly byzantine model naming convention. SM-MA stands for Shimano Mount Adapter, so that'll be universal across models and can be safely ignored now that you're here.

The rest of the model name is the important part. An "F" denotes front brake and an "R" denotes rear brake. The following number (160, 180, or 203) is, of course, the rotor size, with special parentheticals for 203mm rotor conversion. The final two initials respectively describe the caliper type and the frame/fork mount type with either a "P" (post-mount) or an "S" (ISO). To alleviate confusion, we've reiterated the front or rear specification at the back.

To recap, model number SM-MA-F160, P/S Front is for the front brake (F), it accommodates a 160mm rotor (160), it holds a post-mount caliper (P), and it attaches to an ISO fork mount (/S).

  • Durable alloy construction
  • Mounting hardware included
  • Compatible with ISO and post-mount calipers and frames/forks
  • Item #SHI0108
Learn more

What do you think about this product?

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Exact fit

Familiarity:
I've put it through the wringer
Fit:
True to size
Size Bought
160-203 p2p
Height
5` 9"
Weight
180 lbs

Purchased to go from 160 to 203 post to post. No washers needed other than what came with it. Beat on the bike and it holds alignment just fine

Fits as advertised - easy to use

Familiarity:
I've put it through the wringer

Not a ton to write - the adapter is easy to install, true to size and easy to dial in, stays dialed in, and reasonably priced. It's very straightforward - kind of like getting an A on a first grade spelling test, but hey, it's an A.

Adapter, bolts and no washers.

Familiarity:
I've used it once or twice and have initial impressions

I ordered this to mount my Shimano M8020 caliper to my front fork paired with a 203mm rotor. The packaging includes the adapter, and 2 mounting bolts. BEWARE; no cup and cone washers are included. I feel that the washers should be included but understand they are not necessary. Wish they were more clear about what’s included in the packaging. 4 out of 5 starts because the washers should be included. The washers came with my rear adapters.

203mm brakes on RM Instinct

I loved my X2's with 180mm rotors, but I wanted more braking power without spending $500+ dollars for 4-piston brakes. So I did what a lot of people do in my situation and bought big ol' rotors and some adapters. For $100, I picked up rotors and adapters and I now have a noticeable increase in power while keeping the brake set I love. As others have said, the part numbers are very confusing, so hopefully these photos will clarify what's needed for 160mm and 180mm post mount applications. Sidenote: I was advised to avoid the Hope 203mm two-piece rotors on the Fox 34 due to clearance issues. I'm glad I chose the one-piece. It's a very tight fit but they clear, and they're about $15 less. Stoked!

I

Shimano brake adapter 180 to 203

Part # SM-MA-F203 (180mm to 203mm), Post/Post Front/Rear Hope X2 brakes with 203mm Hope one-piece rotors onto my Rocky Mountain Instinct (180mm post mount).

Part

Shimano brake disc adapter 160 to 203

Part # SM-MA-F203 (160mm to 203mm), Post/Post Front/Rear Mounted Hope X2 brakes with Hope one-piece 203 rotors on my Fox 34 (160mm post mount ) fork. I recommend one-piece rotors on the Fox 34 to avoid clearance issues. It's a tight fit.

Part

Perfect.

Familiarity:
I've used it several times

Got some to make my ripmo 203 F/R. Some pictures don't actually match what you're getting.

Works with SRAM Guides

Familiarity:
I've put it through the wringer

Used this for a hardtail build. The profile worked well with the shape of the SRAM Guide RSC calipers.

As Expected

Familiarity:
I've put it through the wringer

Does its thing and does it well. No complaints for this here.

Part works great, Part #'s not so much

Familiarity:
I've put it through the wringer

If you need it you need it. Simple adapter to hook it up. Hit us up if you have any questions on the application for your bike.

For forks with 180mm mounts

My fork has 160mm mounts so this one doesn't work for using a 203mm rotor.

A must.

Shimano's part numbers can be confusing. Be sure to hit the "Chat Now" button to get help from a Gearhead who can help confirm the correct adapter for your frame.

good luck!!

Familiarity:
I've used it several times

work great if you can figure out shimanos part numbers and fitment!!!....wooo hoooo!

Necessary

Familiarity:
I've put it through the wringer

Great little adapters to ensure that your brakes fit your bike.

Required parts

Familiarity:
I've put it through the wringer

If you want to follow the trend of having a 180mm rotor for the rear brake, you will need this if you have a Santa Cruz or any other brand that uses an international standard brake mount.

Does its job

Familiarity:
I've used it once or twice and have initial impressions

Does what you need it to do!

Necessary

Familiarity:
I've put it through the wringer

Works well with not only Shimano, but other brands as well. Just be sure to get the correct one for your application and should be smooth sailing.

Does what it should

Easy to use and does exactly what it needs to do.

Works as intended

Familiarity:
I've put it through the wringer

You will likely need one or two of these to mount up your disc brakes, get the right ones for your set up and youre good to go!

Mount it up

Familiarity:
I've put it through the wringer

Durable and easy to install, brake adapters are necessary on many frames and forks if you are running a larger rotor size.

Is the SM-MA-F203 (180mm to 203mm), Post/Post Front/Rear the correct adapter to go from 180 to 203 on a 2019 RockShox Lyrik fork?

What is the length of the bolts for the + 23mm adapter? Is it M5X23MM?

I am looking at the 160 to 203 post to post adapter. The photo of the part appears to be wrong. Will the part sent actually be a post to post adapter? The one shown is is to post. Thanks

Hi Mike- We unfortunately, don't have a picture for each one but the dropdown will be correct for the one you are wanting!

looking for front fork Post mount to Flat claiper, 160mm Center lock disc adaptor, for 2015 Cannondale 12

What is the purpose of the little plastic clips that come with the mounting hardware?

Since asking this question I found the answer in a Shimano service manual. For anyone curious, the little plastic clips are supposed to be attached to the bolts after they are tightened to prevent them from loosening over time. The bolts come with thread lock already applied so the clips don't really seem necessary, and that explains why everyone gets by just fine not knowing what they are for.

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. Thanks, R

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

I have a realm beach cruser from the 60s it comes stock with springer forks I would like to put a disc brake on the front is there a adapter that will work on the springer forks for a disc brake. I'm about ready to give up and go for a drum brake. Thanks

I have a 2011 Specialized Stumpjumper 29er HT with RockShox Reba RL 29, 9mm-travel w/lockout (15.5": 80mm travel and I am hoping to install the Shimano XT SM-RT86 6-Bolt Disc Brake Rotor (180mm) on the front. I do not know which mounting bracket I need? Can you please help me? I really appreciate it. Thank You. Austin Blasingame

I have a Mach 5.7 pivot with fox float fit Tlc up front what brake adapters would I need to go to 160 in back and 180 up front

Looking to put xtr 9000s on cannondale XLR carbon 90 Lefty, it had 180/160 rotors front & rear respectively. replacing XO brakes, what mounts do I need?

I have a Mach 5.7 pivot with fox float fit Tlc up front what brake adapters would I need to go to 160 in back and 180 up front

Following the formula outlined above I need an SM-MA-R180 P/P but don't see that as an available option for ordering. Does running that setup not require an adapter?

Which adapter do I need for the rear brake on a Santa Cruz Bronson Frame? Using XT Brakes.

I have done some homework on your disk brake adapter question, and you will have to use item “SM-MA-F160,P/S”. If you have any additional questions, please feel free to call or email me at dmyers@backcountry.com

What type of rear caliper mount type do I need for 2014 Niner EMD 9, is it ISO, P/S or P/P)? Also, what type of front caliper mount type do I need for RockShox Reba RLT with 15mm thru axle (P/P or P/S)? Thanks in advance.

Hello, On this particular frame for the rear you would need a P/S adapter and on the front you would need a P/P adapter. Thank You.

Is there a rear Post to Post adapter for...

Is there a rear Post to Post adapter for shimano brakes with 180 mm rotor?

The post to post 180mm mount for the front, will work on the rear.

is there a rear disc convertion or a non...

is there a rear disc convertion or a non disc bike

Yes there is. Upgrading your frame to a new one with built in brake mounts is your best choice, but if that isn't an option, you can try this! http://2btherapy.com/bikes/brake-therapy-conversion-kit

I noticed all options above include IS...

I noticed all options above include IS attachment, EXCEPT the pic of the "203 front" which appears as a post mount adapter for 8" remaining 74mm; such as all new shimano brakes are. BIG QUESTION: if I order the 203 front will I receive the 74 to 74mm, and excuse the IS designation (the photo goes with this selection, i believe). Thanks!!

I pitty da foo... I would not excuse the designation. Probably sold out of the 74-2-74 mounts. If it says IS it most likely is

Well pitty putty- I'll be the eternal optimist; six designations, six pics, and one is P/P, good for the return at least and a damn good price as a generic adapter for all the mutts out there.

Which adapter do I use for post mount rear...

Which adapter do I use for post mount rear frame tabs (new Turner have PM rear instead of 51mm IS)

Choose the Rear IS Frame for the size of rotor you are running. So all three will work but if you are running 160mm rotors get the 160 adapter.

Standard Avid and Shimano post mount brakes will not need an adapter for 160mm rotors. Use one of them. You should not be able to run IS mount rear calipers on this frame. There maybe an adapter - but the rotors will have to be bigger - 203mm witch most likely will not fit the frame.

I'm comfused, the item # shi0108 fits in...

I'm comfused, the item # shi0108 fits in a post mount fork with IS caliper and 160 mm rotor?

this adapter is to convert the post style mounts to shimano style mounts. If you have a 160 mm rotor, choose the Front 160. Or get a new fork.

the 180 rear adaptor will fit the 170mm...

the 180 rear adaptor will fit the 170mm rotor?

Just a guess here, but that doesn't seem like it would be the hot set up. It would probably sorta work, but since the 180 adapter sets the caliper further from the axle, I think the pads might not get full contact with the rotor. The result of that would be poor braking and uneven/fast pad wear. What 170mm rotor are you rocking? Magura?

Brake track is very crucial, so caliper placement is important. 5mm shims may work on a 160 setup- if you can't find the correct adapter which I suggest.