Converting a Jannd handle bar bag into a seat post bag.

Here is what you need:
Stem,plastic shim and 4" long piece of Alu tubing from handle bars or seat tube.

My seat post is a 27.2 so I used a 1-1/8 stem with a piece of plastic cut from a plastic milk container as a shim. Any piece of thin plastic should work besides it helps protects the seat post from gouges.
Next I cut a piece of tubing from a very long seat post I'll never use for the cross bar. After grinding away any rough edges I installed standard end caps.





When put together it looks like this.
next install the Jannd quick release with bag.

Click any image for close up.