5mm would be a squeeze for hydraulics, but you would be able to use the top cap of the before mentioned headsets for larger headtubes.
Yep, that's why I'm planning on a 52mm ID, 54mm-56mm OD headtube. Integrated hoses and cables are nice, but I'd like to be able to steer too.
@Brommers started
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5mm would be a squeeze for hydraulics, but you would be able to use the top cap of the before mentioned headsets for larger headtubes.