I have a Cannondale Trail SL SS from 2014 or so, and I'm having trouble figuring out what to replace the upper headset bearings with (they are knackered). The fork is the one the bike came with, a Cannondale Fatty with a 1.5in straight head tube. The headset that came with the bike was likely the Cannondale KP191, this is (I think) semi-integrated, in that the lower bearings are in a cup that is pressed into the headtube, but the upper bearings are pressed directly into the headtube.

The lower bearings wore out some time ago and at that point I replaced the lower cups with a Cane Creek 40-series EC49-40 Bottom Assembly. This worked fine, and the replacement bearings for this seem to be easy to obtain (they're standard, and just pop in/out of the cups).

The issue I'm having is with the top. The existing bearings looks like this:

Existing bearings

Existing bearings again

(The inner part of the bearing separated from the rest, which may or may not be visible in the picture.)

Maybe a better picture is here:

Replacement bearings

(the upper bearings are the third from the right in the last row).

I can't seem to source a new KP191 anywhere (they are sold out, which makes me think they aren't made any more), I'm not sure what to search for when it comes to just replacing the broken upper bearings (they have a flange on them, no number I can see, so difficult to search for).

The question is: how can I find replacement bearing?

If the answer is "you can't", what are my alternatives? I've spent an hour or so trying to figure out what replacement headset might be (I only need the upper), but they all seem to have upper and lower cups for the bearings. Can I actually fit one of these? I.e. press cups into the headtube (where the bearings are pressed in directly just now) and seat the bearings in those? Or what?

  • Have you checked with some local bike shops? Part of their skill set is tracking down replacement parts or alternatives if unavailable.
    – Armand
    Mar 12, 2022 at 14:30
  • What is the bore diameter of the upper headtube? Is it a plain bore? Mar 12, 2022 at 15:42
  • @Armand I did check with the LBS but didn't get very far, hence the question here. Mar 12, 2022 at 16:11
  • @NathanKnutson I'm not sure what bore diameter means? Or plain bore? Mar 12, 2022 at 16:12
  • What is the internal diameter of the head tube, and is it a plain bore or is there some kind of bearing seat. Mar 12, 2022 at 19:24

1 Answer 1


I don't know for sure without measuring, but the headset cup looks very much like the SI cups (QHDST) for use with Headshok and Lefty, which wouldn't be a big surprise as the 1.5" steerer suggests a Lefty upgrade path.

However, the top bearing shown is very unusual and while I know a standard angular contact bearing exists to go into Headshok cups to allow use of a 1.5" steerer (cf. Cannondale Slate Apex), you will need to take accurate measurements to get what you need* and be able to source any necessary shims and trims to make the job neat.

If I was in your position and didn't have a nearby Cannondale dealer, I would email CannondaleSpares.com to ask for their advice before doing the measurements and ordering non-standard parts. They should be able to give you a lead time or confirm discontinuation and suggest an alternative. If you went to a Cannondale dealer and they didn't check with the Cannondale distributor/warranty department, they have just been wasting your time as well as their own.

*bearing inner diameter, outer diameter, thickness, inner angle, outer angle.

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