Mechanics at a repair place told me that my bike needs a new headset. For the moment, I have a semi-integrated / zero-stack Cane Creek VP-A45AC. I went afterwards directly to a bike shop asking for a new headset, and they sold me an external Massi headset. I am no expert in headsets, and I don't know if 1) the shop sold me this external headset because it's interchangeable with a semi-integrated one 2) they made a mistake and I need to go back.

I didn't find much on external / semi-integrated headsets compatibility, does someone now if I can use this external one on my bike (provided the dimensions are correct, which seems to be the case) ? Thanks.

1 Answer 1


No, there are no external headsets that are directly interchangeable with an internal one. There are external headset lowers for tapered forks that use the same bore dimension as internal for non-tapered, which might have been the source of confusion.

If you have the pictured headset, those are probably a standard bearing that can be replaced without needing a whole new headset, providing there's nothing wrong with the other parts.

  • My Trek road bike has what's described as "semi integrated" headset. Seems to me it's just external cups having the same outside diameter of the frame's headtube. The bearings sit in these cups. Thus, if I were to get a headset that's EC34/28.6|EC34/30, it would work because that's essentially what's there now, not a true ZS
    – Jeff
    Commented Jul 9, 2020 at 19:04
  • @Jeff Correct, those are essentially just external headsets with an integrated look. Commented Jul 9, 2020 at 23:02

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