Could there be a narrower tube built into the seat tube that the post sit inside and the TT slides over? So the bolts you can see clamp all 3 parts together as one?
I imagine the frame is bonded or moulded in one part, those bolts are just seat post binders, they don't hold the frame together.
I imagine the frame is bonded or moulded in one part, those bolts are just seat post binders, they don't hold the frame together.