UK Patent 1897 # 16,715 - Gradient

UK Patent 1897 16,715 - Gradient main image

A year after his first ‘Gradient’ derailleur (see UK Patent 1896 1,570), Edmund Hodgkinson produced this, much more sophisticated and coherent design. This three speed system now looks extremely similar to a 1930s TriVelox. One difference is that Edmund Hodgkinson placed the large cogs towards the outside and the small cogs towards the centre of the wheel hub.