Luxury.

A motorcyclist worthy of the name does not ride these things for the creature comforts. You're exposed to the elements, there is usually little storage and, especially on classic bikes, there aren't any gadgets to keep you company, no cup holders, climate control, clock, radio, etc.

(In fairness, the Norton Commando Interstate had an electrical socket to power a shaver, radio or inspection light. And some of the older Triumphs came with a removable inspection light hidden in the fuel tank panel, very cool)

The engineers at BMW must have thought that something more was in order. A clock was available as an optional gauge, we have it and it is very handy; and an electrical socket was fitted under the right-hand side panel, as a means to power anything you wanted provided you wired it to the correct DIN/Hella plug.

We have an extra one of these sockets mounted on the handlebar of our GS, to power a GPS navigator, and now, thanks to this nifty adapter (in the cardboard box, on the right), I have two usb ports that I can use to charge my smartphone and my GoPro camera. What luxury!

In the cardboard box, on the left, you can see another twin usb socket set, that one will go on the Honda as soon as I have the time.

For more, see http://burnsmoto.com/