I know you get headset questions all the time, hopefully this one mixes things up a bit. I recently acquired a 2015 litespeed CX frame, which has a 44 mm head tube. It is listed as having a height of 12 cm. I picked up a fork, from a Cannondale Synapse 2018, size 58.

To my great surprise, the fork is listed as having a 1 1/8" to 1 3/8" tapered steerer. The headset on the Synapse is listed as a "Synapse Si". Most sites I have found are about trying to fit an alternate fork into a Cannondale headtube, as opposed to the other way around. I have found the following webpages: https://www.cannondaleanswers.com/definitive-guide-cannondale-frame-headset-fork-compatibility-for-mountain-bikes/ https://cannondaleexperts.com/products/cannondale-synapse-carbon-1-3-8-tapered-headset-no-crown-race-k35038?variant=31365859639433

Is there any way to get this fork onto my 44 mm headtube? Thank you!

1 Answer 1


A lower akin to an EC44/40 could be made to do this, but it doesn't exist commercially. In other words it would be an EC44 frame interface and take the sort of bearing that goes in IS49, whereas EC44/40 does the same but with IS52. This hypothetical lower can't be described in SHIS because Cannondale 1-3/8 forks all have integrated crown races.

So yes, but it would have to be a custom made cup, i.e. turned out on a lathe just for the purpose. Using EC44 on a bike intended for ZS like this will of course slacken the geometry.

  • I did find some bearings you could buy separately (FSA MR031) but if I understand what you are saying, the cup is the fundamental issue. It seems that getting a different fork will be the best answer.
    – ektogamut
    Nov 2, 2020 at 5:55
  • @ektogamut That's correct. It is true that if you had a bearing with the right outside diameter and height to fit a nominally EC44/40 lower cup and the inside diameter and angle to fit a Cannondale 1-3/8 integrated crown, such as the one you mention, then you could do it that way too by adapting an off-the-shelf EC44/40 cup, but I don't believe that bearing exists. Nov 23, 2020 at 21:00

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.