HK has been loaned a little-used Birdy Touring nearly two decades old. While tweaking it for multimodal touring, I finally got round to checking why the seatpost gradually drifts down and tends to twist. Half the clamping mechanism is missing!
This obsolete frame design has a square section penetration through the top tube and seat tube in front of the seat post. A pair of shaped plastic blocks are squeezed together by a long QR and those blocks clamp the seat post. There is no slot in the frame or any opportunity to fit a normal external seat clamp.
Birdy long ago changed their frame design to use a normal seat clamp and the obsolete seat clamps appear to be unobtanium after the usual searching.
It seems that bodging a replacement plastic block and assorted washers might be my only option. Any other suggestions?
