I’m thinking that there should be a serial number somewhere on my model 18 but so far, I haven’t found it. With bicycle thefts in general being such a problem nowadays, I’d really like to make a note of it.
On the model 15 there is a removable plastic insert below the handlebars I was looking for a fuse box and stumbled upon the serial completely by accident. Obviously the models are different but I’d assume have similarities