I agree and everyone wants to know who is making it!  — Tan Tan can openly sell the frames, but there are subtle differences that seem designed to skirt around IP infringement.

One example: seat posts don’t interchange between the X68 and the SL8. The X68 is about 1mm wider, so while it looks nearly identical the difference are so subtle you just don't notice them and from what i can see this is the only differences this is Just enough of a difference to avoid a direct copy, I think.

Thanks. Confirms my suspicions. Lots of folks upthread were claiming the tantan frame wasn't from whatever source the others were, given that "it has a different headset size". Now we know it doesn't.
Mine came built so I didn't want to pull the hoses to change the bearing...just added external grease. I avoid the rain as much as possible, not an option for Sander I suppose.

I think that it is a "made in Taiwan" stickers.

This issue has actually been discussed at length on the Weight Weenies forum regarding the genuine SL8 as well. It looks like the bottom of the transition spacer isn’t perfectly flat — it dips at the front and ends up rubbing against the top tube.

You could try lightly sanding it down using fine sandpaper on a flat surface to level it out, or alternatively, order a set of genuine spacers and see if that resolves it.