This winter I decided to re-furbish my old steel framed 531c Mercian, vintage 1988. Originally built up with Shimano Sante which has a v.low headset stack height (32.5mm). Sante headset got replaced with 105SC in 90s, and I've just chucked the 105SC away 'cos it was notchy. To replace it this time only available headset that looks to fit is a 1" Chris King Gripnut. I got a NoThreadset and a Gripnut Conversion from separate sources. Bearing cups and crown race went in place easily (with correct tools), however there seems to be a defect with the (ebayed) Gripnut.
On the NoThreadset adjustable race the taper that locates in the bearing inner race is very flush to the underside face, but on the Gripnut the similar taper is produced on a boss that stands 1.5 - 2mm proud of the underside face. Consequently the Gripnut when assembled leaves a stoopid great gap between it and the top bearing cup. Clearly something is wrong, and assembling the NoThreadset parts shows this gap should be more like 0.2mm.
Before I rush out to order another Gripnut, which may possibly be exactly the same, please could one of you kind people confirm the taper on a Gripnut is usually in the same form as that on a NoThreadset? The alternatives for my build are pretty nuclear, new forks minimum.
I have emailed Chris King tech people but they's not answering!