If you are sensible with your saddle-height on your bicycle you might need a tool to set up your saddleheight. This tool is built with the use of a 1m aluminium-L-shaped rail from the hardware-store. (20*18x1,5mm) The bottom piece is glued in place with superglue.

Usage: Put the pointy piece in your Shimanoe hollowcrank-bottom bracket and slide the top piece onto a defined place on your saddle. measure.

added: The screw is not working with my printing. So I left it out and took 2 layers of tape to make the sliding piece stick a little.

added: glued on a metric metallic tape measure from china

added: mounting-plate to mount it on your wooden Zwift-table