I have a NOS Voodoo Wanga in steel. Its a 26″ compatible frame. A look in the parts zone in the man cave reveals i have a Hope ‘standard’ headset. The top cup is marked 1-EC34/28.6 and the bottom cup is marked A-EC34/30. From measuring with my verniers the first number is the internal diameter of the frame head tube, and the second numbers are the internal diameter of the split ring that sits around the fork steerer and in the top and bottom bearing.

This is all fine if i have a 1 1/8 straight steerer fork. If i buy a tapered steerer fork, is it possible to get a different lower cup that would accept a tapered steerer fork? If so, how do i choose what i require?

No.

Sadly the ‘taper’ of a tapered fork is 40mm, so no way it will fit in a standard ‘1-1/8th external’ headtube.

You may have seen some folks converting and this is possible if they have an internal headset, by replacing it with a bigger external. These frame need to have a 44mm headtube, just enough space to fit the cup and 40mm taper steerer.

EDIT: Steel frame, could possibly get a new headtube fitted, unlikely though.

Ok, thanks. It seems this is square peg and round hole territory. Shame 🙁