I got a new (to me) Dahon Cadenza in the largest frame size. I'm at the top of the suggested rider height range, but it turns out my legs are longer than average, so I need a bit more seat post than the mark allows, ideally up to 25mm more.
Here's the thing: the bike has a shim in the frame around the seat post (from manufacturer) presumably designed to protect this area of the frame. As such the load of the seat post is presumably transferred to the shim then the frame.
The shim goes down into the frame to just below where the chain stay tubes and top tube bridge (a half-tube brace) meet the seat tube. Is this therefore OK?
Numbers:
Seat post minimum insertion 80mm
Actual insertion 55mm (in contact with the shim)
Shim insertion 80mm into frame
Images attached may help. As you can see the shim is quite substantial and it doesn't move easily if I try to pull it out.
I ask because I'm fond of this type of seat post (Biologic Zorin Postpump) but not above getting a replacement if needs be.
Thanks for any ideas.
by YU_AKI