Sounds like the short on-one headtube is just a teeensy bit too short for the steerer/headset combo. Although i see it is an on-one branded headset 😆 If you managed to rectify it by filing the inside of the wedge, there must have only been a few mm in it…
I wonder if manufacturers anticipated this arising?
Is there a ‘standard’ length of taper already set?
ie steerer returns to 1.125″ by x mm above the crown, to allow frame and headset makers to plan their own parts.
Peter, what is the length of your headtube? How does that compare to short headtubes on ‘normal’ frames? Millie has had (small or laydeez) frames with 90-100mm headtubes before, it would be a shame to lose the option of making them so short becasue you wanted to put a tapered steerer in.
[edit] oh, i see lots of you beat me to all that. ^^ Must type faster.