Chinese Titanium Frames...

[AFE]

I mounted 50mm tires and there is definitely enough clearance for at least 55mm. See pictures for clamping mechanism and total weight. I did not weigh the bare frame. Clamping with the titanium seatpost works well because you can tighten it up. Don't know if it works with 5nm on a carbon seatpost. I weigh > 100kg.

[Lanfi]

I mounted 50mm tires and there is definitely enough clearance for at least 55mm.

Is this the "Type A" version of the frame?

[CycOps]

I mounted 50mm tires and there is definitely enough clearance for at least 55mm.

You run a 1x drive train. Do you think 55mm tires would work woth 2x drive train, or would clearance be an issue around the front derailleur?

[AFE]

Is this the "Type A" version of the frame?

Yes