What is the maximum input torque that can be sustained by sturmey archers internally geared hubs. The website is surprisingly short on info about this.
I'm specifically interested in the hybrid gearing hubs that allow fitting a 9 speed cassette onto a 3 speed IGH. But I expect the internals of all the 3 speed hubs are the same. http://www.sturmey-archer.com/en/products/detail/cs-rf3-silver
The website mentions a maximum sprocket size of 34 teeth, but without the minimum chainring size that's rather meaningless.