BSA DP

The Birmingham Small Arms Dual Purpose Hub Gear is the Holy Grail of geared hubs. It was a two speed hub that could be converted from fixed to free at the flick of a control lever. On the right of the hub was the control to change the gears, and on the left was another control rod that locked the hub when pulled.

This is what it looks like. Our thanks to Eddie Wallace, who sent in these pictures of one he used for many years and is now dismantling to check its condition. 

This gear is described in Newnes Cycle Manual for 1936.