My mtb (SERIOUS Rockville), which currently has rim brakes, has these holes at the back of the frame and I am trying to understand their use. Are these for disc brakes? Are these for disc brake converters?

enter image description here

  • 1
    No, but some of them might work as mudguard or rack mounts.
    – Swifty
    Commented Jul 21, 2018 at 19:57
  • They look a bit lightweight for brake mounts. Does the front fork have disk mounts?
    – Criggie
    Commented Jul 22, 2018 at 1:05
  • 1
    Are the same holes on the opposite seat-stay as well. If so, they are for rack/mud-guard, as suggested by @Swifty
    – Carel
    Commented Jul 22, 2018 at 7:36
  • 2
    Looks like like decorations. Not in right spots for brakes and don't look threaded for racks or fenders... Commented Jul 23, 2018 at 0:29
  • I agree with @whatsisname Also, there appears to be a ridge that runs around the upper and left sides of the triangle of metal these sit in, which would make it difficult to bolt rack or fenders onto.
    – SSilk
    Commented Jul 23, 2018 at 14:03

1 Answer 1


You’ll find similar decorative holes on the opposite side, which is an indication that they are not for disc brakes because those get mounted on the left hand side only.

The holes are mostly through quite a thin section of metal, recessed, which is probably too insubstantial to do anything useful, so no disc brakes.

The ‘Street’ model comes with mudguards and a rack ready mounted through the lower hole, which you’ll see is in a place with thicker metal and presumably the hole is threaded for this:

Serious Rockville Street mudguard mount

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.