Post mount - Flat mount conversion

trago1987
trago1987 Posts: 14
in Workshop
Good evening everyone hope you are all well.

I am looking at upgrading my commuting bike for the winter and getting the 105 R7020 Disc Groupset.

I see that this groupset comes with flat mount calipers, is there a way I can convert this to fit my post mount.

Any guidance would be greatly appreciated.

Comments

  • david37
    david37 Posts: 1,313
    first world problem that one.
  • darrell1967
    darrell1967 Posts: 477
    david37 said:

    first world problem that one.

    Nice!!
  • veronese68
    veronese68 Posts: 27,692
    edited September 2020
    I didn't think it was possible as flat mount calipers are taller than post mount. So to fit flat mount you need to attach the caliper lower than the face of the post mount.
    I think someone has said there are adaptors available, so I may be mistaken, but I can't see how they'd work unless they angle the caliper and move it round the disc. If so that would be fugly.
    Kinesis Pro6
    Marin Nail Trail
    Cotic Solaris
  • reaperactual
    reaperactual Posts: 1,185
    edited September 2020
    This is a guide to see if it's possible with your post mounts. You can also print and cut out an actual size template to check first.

    https://www.assolutions.ca/flat-mount-caliper-to-post-mount-adapter-guide/

    This company supplies the adaptors and are based in Canada but do international shipping.
  • veronese68
    veronese68 Posts: 27,692
    reaperactual said:

    This is a guide to see if it's possible with your post mounts. You can also print and cut out an actual size template to check first.

    https://www.assolutions.ca/flat-mount-caliper-to-post-mount-adapter-guide/

    This company supplies the adaptors and are based in Canada but do international shipping.

    Not as bad as I thought, didn't realise they would drop between the posts like that.
    Kinesis Pro6
    Marin Nail Trail
    Cotic Solaris
  • reaperactual
    reaperactual Posts: 1,185
    veronese68 said:

    I didn't think it was possible as flat mount calipers are taller than post mount. I can't see how they'd work unless they angle the caliper and move it round the disc. If so that would be fugly.

    Didn't think it would be possible either, just happened across a Google pic last week when searching for an unrelated adaptor.

    Quite a simple, elegant solution and I agree how 'fugly' would the alternative look if this wasn't possible. 😬👍



  • jpj84
    jpj84 Posts: 51
    Alternately, I've used Deore M6000 post mount calipers with road shifters, and they work fine
  • pilot_pete
    pilot_pete Posts: 2,120
    When you look at the price of those adapters - $40 each, it would make more sense to buy post mount calipers. I bought a 105 groupset a year or so back and bought Deore post mount calipers at £25 each. For the same price you could even have a spare caliper!

    PP
  • reaperactual
    reaperactual Posts: 1,185
    edited September 2020
    pilot_pete said:

    When you look at the price of those adapters - $40 each, it would make more sense to buy post mount calipers. I bought a 105 groupset a year or so back and bought Deore post mount calipers at £25 each. For the same price you could even have a spare caliper!

    PP

    Were not talking USD it's $40 CAD probably works out at around a Fiver each in real money! 🤣
  • arlowood
    arlowood Posts: 2,561
    edited September 2020
    reaperactual said:

    pilot_pete said:

    When you look at the price of those adapters - $40 each, it would make more sense to buy post mount calipers. I bought a 105 groupset a year or so back and bought Deore post mount calipers at £25 each. For the same price you could even have a spare caliper!

    PP

    Were not talking USD it's $40 CAD probably works out at around a Fiver each in real money! 🤣
    Actually closer to £23 a pop but there will probably be shipping and import taxes to add on. Looks like the solution is to go down the Deore caliper route and sell off the 105 R7020 flat mount calipers. Or bite the bullet and buy a flat mount frameset as it looks like post mount will be obsolete on road bikes before long if not already
  • reaperactual
    reaperactual Posts: 1,185
    edited October 2020
    arlowood said:

    reaperactual said:

    pilot_pete said:

    When you look at the price of those adapters - $40 each, it would make more sense to buy post mount calipers. I bought a 105 groupset a year or so back and bought Deore post mount calipers at £25 each. For the same price you could even have a spare caliper!

    PP

    Were not talking USD it's $40 CAD probably works out at around a Fiver each in real money! 🤣
    Actually closer to £23 a pop but there will probably be shipping and import taxes to add on. Looks like the solution is to go down the Deore caliper route and sell off the 105 R7020 flat mount calipers. Or bite the bullet and buy a flat mount frameset as it looks like post mount will be obsolete on road bikes before long if not already
    Yes I was joking, hence the emoji, £23.04 yesterday to be precise. Still a lot cheaper than biting the bullet and buying the flat mount frameset solution! 🤪

    Cost aside and to answer the OP's question, yes an adaptor is available that can be used to fit a flat mount caliper to post mounts.
  • trago1987
    trago1987 Posts: 14
    Thanks for all the comments people and advice it's much appreciated.
  • trago1987
    trago1987 Posts: 14
    Ended up getting new calipers and sold the other ones for more so I was quids in!

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