Re: Dual-Chain drive train

Zen Cycle <funkmaster@hotmail.com> wrote:

https://www.bikeradar.com/news/buffalo-utility-s2
 
Made for developing countries to allow for easier transportation on
cargo bikes, without the exposure and complexity of an external
derailleur or hand-operated shifting (for an internally geared hub). It
was developed and patented with the help of SRAM.

Are derailleurs really that bad? A whole new bike for the sake of a granny
gear seems slightly extreme. Internal pawls at small radius are going to
be more stressed  and harder to build than a rear sprocket of larger radius.

I'll admit that the narrower flange of a multispeed rear hub impairs the
lateral strength of the rear wheel, but a hub with flanges spaced to leave
room for a two-cog stack would be vastly stronger. What is the "exposure"
alluded to above?

Thanks for reading,

bob prohaska