Yes you could fit either a threaded or unthreaded 1" headset and fork either by using headtube reducer shims plus a 1" headset and fork or by using a headset designed to marry a 1 1/8" frame to a 1" fork - the aforementioned CK Devolution being one such example.
I suspect shims and a 1" headset may be cheaper but also possibly less structurally sound.
I've thought about using shims to fit a 1" threaded headset and fork to my Principia for an even more Cannondale Track-esque look but given that the frame is a 58cm it has quite a long headtube and I think I'd struggle to find a 1" threaded fork with enough steerer.
Yes you could fit either a threaded or unthreaded 1" headset and fork either by using headtube reducer shims plus a 1" headset and fork or by using a headset designed to marry a 1 1/8" frame to a 1" fork - the aforementioned CK Devolution being one such example.
I suspect shims and a 1" headset may be cheaper but also possibly less structurally sound.
I've thought about using shims to fit a 1" threaded headset and fork to my Principia for an even more Cannondale Track-esque look but given that the frame is a 58cm it has quite a long headtube and I think I'd struggle to find a 1" threaded fork with enough steerer.