Author Topic: Birdy old-style seat post clamp replacement?  (Read 2962 times)

LittleWheelsandBig

  • Whimsy Rider
Birdy old-style seat post clamp replacement?
« on: 25 February, 2023, 04:55:47 pm »
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?
Wheel meet again, don't know where, don't know when...

LittleWheelsandBig

  • Whimsy Rider
Re: Birdy old-style seat post clamp replacement?
« Reply #1 on: 04 March, 2023, 11:05:26 am »
I have purchased some 28mm diameter Nylon rod that will be cut, drilled and filed to replace the missing bits but that will have to wait until I get back from Oz. The finished square-section blocks will be 22mm across the flats.
Wheel meet again, don't know where, don't know when...

LittleWheelsandBig

  • Whimsy Rider
Re: Birdy old-style seat post clamp replacement?
« Reply #2 on: 11 April, 2023, 03:08:51 pm »
Completed yesterday and hopefully being used for a multimodal trip next weekend.
Wheel meet again, don't know where, don't know when...