Forum home Mountain biking forum MTB workshop & tech

Rotor upgrade 160mm to 180mm

Hi

I wanted to upgrade my dics from 160mm to 180mm under this black friday weekend.
I have never done this and need some help, iam upgrading my bike myself (mostly) without any need of a shop so iam learning on the way.

I currently have Shimano BR-MT200 hydraulic calipers and 160mm rotors stock from factory.

I wanted to upgrade to these rotors(SM-RT64):
https://bikester.se/shimano-sm-rt64-brake-disc-center-lock-1105742.html

My question is: will these fit my caliper? I know that my caliper does not fit in the “compatible with” category. But does that really matter, they are just dics? I have read and it looks like my caliper do support 180mm dics.

I do not want to replace my caliper, just the dics and was wondering if this is possible?

I know i have to buy a PM/PM adaptor for the 180mm to fit onto my frame/fork.
Can i use the same adapter for both the front and back?

https://bikester.co.uk/bike-parts/disc-brakes-accessories/brake-disc-adapter/304455.html

Thank you

Posts

  • whyamiherewhyamihere Posts: 7,410
    That will all work as long as you have centrelock hubs. This means that the rotors are connected to the hub using the lockring shown in the picture of the rotor you have linked to rather than being attached with 6 bolts. If you do have 6 bolt hubs, you will be able to get similar rotors which are compatible with the hub.

    As a side point, I wouldn't bother increasing the size of the rear rotor unless you ride proper downhill tracks or are very heavy. The larger rotor can make it easier to lock the rear wheel (which is less of a problem on the front due to the way weight shifts under braking), which is less effective for actually slowing down and destroys trails.
  • anim4lanim4l Posts: 10

    That will all work as long as you have centrelock hubs. This means that the rotors are connected to the hub using the lockring shown in the picture of the rotor you have linked to rather than being attached with 6 bolts. If you do have 6 bolt hubs, you will be able to get similar rotors which are compatible with the hub.

    As a side point, I wouldn't bother increasing the size of the rear rotor unless you ride proper downhill tracks or are very heavy. The larger rotor can make it easier to lock the rear wheel (which is less of a problem on the front due to the way weight shifts under braking), which is less effective for actually slowing down and destroys trails.

    Thank you for your answer
  • figbatfigbat Posts: 680
    I agree with @whyamihere - I run 180mm on the front and 160mm on the back of my hardtail and have never failed to stop yet. Just make sure you get the same disc mounting type and if you have centrelock discs you'll need the right tool to undo and remount them.
    Cube Reaction GTC Pro 29 for the lumpy stuff
    Cannondale Synapse alloy with 'guards for the winter roads
    Fuji Altamira 2.7 for the summer roads
    Trek 830 Mountain Track frame turned into a gravel bike - for anywhere & everywhere
  • As above - I run 180F and 160R on both FS and HT bikes that have been to Wales and other places with big hills. Never felt the need to go any bigger. I run Shimano SLX or XT brakes.

    Did you answer the question about whether your existing rotors are centre lock?
    "Ride, crash, replace"
  • anim4lanim4l Posts: 10
    billycool said:

    As above - I run 180F and 160R on both FS and HT bikes that have been to Wales and other places with big hills. Never felt the need to go any bigger. I run Shimano SLX or XT brakes.

    Did you answer the question about whether your existing rotors are centre lock?

    Yes, i have centerlock wheels. Did manage to buy 180mm on both, hope it works. Also i did buy the same adapter for front and back, PM/PM. Hope that works too.
  • figbatfigbat Posts: 680
    Just to check, the PM adaptor - often frames are set up for a smaller rear disc than front, so you need a bigger adaptor at the back then the front if you are running the same size discs. Also, don’t forget that centrelock removal tool - some can be done with a bottom bracket tool but others (like mine) need a dedicated tool. Not all centrelocks are the same.
    Cube Reaction GTC Pro 29 for the lumpy stuff
    Cannondale Synapse alloy with 'guards for the winter roads
    Fuji Altamira 2.7 for the summer roads
    Trek 830 Mountain Track frame turned into a gravel bike - for anywhere & everywhere
  • Let us know how you get on.
    "Ride, crash, replace"
  • anim4lanim4l Posts: 10
    billycool said:

    Let us know how you get on.

    Got it working great. Very easy to change out the centerlock dics. Only issue i had was align the dics so it did not touch the pads, that took the longest time to fix. Anyway iam happy with the results, thank you very much all for helping. Much appreciated. Here is the final result:


  • JBAJBA Posts: 2,719
    anim4l said:

    ... Only issue i had was align the dics so it did not touch the pads, that took the longest time to fix.

    I hope you meant align the calliper. The disc only has one position.

    “Life has been unfaithful
    And it all promised so so much”

    Giant Trance 2 27.5 2016 ¦ Sonder Broken Road 2021¦ Giant Revolt Advanced 2 2019 ¦ Giant Anthem 3 2015 ¦ Specialized Myka Comp FSR 2009
  • anim4lanim4l Posts: 10
    JBA said:

    anim4l said:

    ... Only issue i had was align the dics so it did not touch the pads, that took the longest time to fix.

    I hope you meant align the calliper. The disc only has one position.

    Yes of course 😋
  • Good work. Hope you notice the difference. Don't forget to let everything bed in.
    "Ride, crash, replace"
  • steve_sordysteve_sordy Posts: 2,139
    Shouldn't that be "don't forget to bed everything in"! :)
Sign In or Register to comment.