There's also the Schlumpf drives, which fit inside a standard bottom bracket.
http://www.haberstock-mobility.com/en/products/schlumpf-drive.html

Only two speeds though, like the HammerSchmidt.

Why not have the gears inside the bottom bracket?
I have an ng-grid that utilizes the showSelectionCheckbox: true property with a custom checkboxCellTemplate. 

If I remove checkboxCellTemplate I get the functionality I want where only one checkbox can be clicked at a time and clicking another checkbox will remove the selection from the previous one. 

I need the template to call a specific function so my question comes down to what property to I have to pass in the template so it can be aware of the multiselect property? 

The plunker can be found at http://plnkr.co/edit/nULoI4?p=preview.
