3) Singer Featherweight
Looking for a lighter weight sewing machine, I stumbled across the Singer Featherweight. This is a really nice, small, but proper sewing machine. In contrast to most older machines, it’s body is made from aluminium not steel, meaning that it weighs around 6 kilos - perfect for my purpose!
To solve the electricity problem, I bought a small 300W inverter that runs from a 12V battery.
After much measuring, drilling and screwing (not that kind) here is the result

The inverter is mounted on the underside of the wooden board, and the battery is lazily resting on the floor.
This set up works very well and I spent a few happy afternoons sat by the river making some pencil cases and shopping bags. Many of what one might term ladies of a gentler disposition showed great interest in my contraption.
However I am still not entirely satisfied - when I am riding I really can feel the weight of the machine dragging me back. I think that it would be possible to replace the motor for a DC-motor, thus eliminating the need for an inverter and perhaps even shaving off a few grams with a lighter motor.