Yet Another Cycling Forum

General Category => Freewheeling => Folders => Topic started by: LittleWheelsandBig on 25 February, 2023, 04:55:47 pm

Title: Birdy old-style seat post clamp replacement?
Post by: LittleWheelsandBig 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?
Title: Re: Birdy old-style seat post clamp replacement?
Post by: LittleWheelsandBig 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.
Title: Re: Birdy old-style seat post clamp replacement?
Post by: LittleWheelsandBig on 11 April, 2023, 03:08:51 pm
Completed yesterday and hopefully being used for a multimodal trip next weekend.