On 8/1/2020 2:52 PM, AMuzi wrote:

snip

The unique axle thread discussed here is on Sachs Super Seven and P5
besides other products:
http://www.yellowjersey.org/suprsevn.html

I thought that the SRAM Dual Drive was a very elegant design, especially
suited for folding bicycles. You could get full range of gears without
the need for a front derailleur. Now, with 11 x 1 and 12 x 1 gearing
there's less of a need for that level of expense and complexity, though
on small-wheeled folders there would still be an advantage.