have you heard of the motorbikes Wooler made? (Thanks Steve!)

how cool was the inventor? He only used 2 nut sizes, so you only have to carry one wrench with a two sizes at opposite ends, and a screwdriver. The wheels are interchangeable.

This motorcycle is usually housed at the Sammy Miller museum (and restored by them), the bike is one of the machines in the collection of the British Motorcycle Charitable Trust (www.bmct.org). John Wooler had a very inconventional approach to motorcycle design (as can clearly be seen!) from his debut at the 1911 Olympia show, an approach that he maintained throughout the next 45 years.

https://greasengasoline.wordpress.com/2012/02/29/1955-wooler-motorcycle-flat-four/
https://www.vintagebike.co.uk/pictures/1955-wooler-flat-four/