nukezero said:
I was just wondering if anyone ever blown a IGH hub (shimano nexus or similar) by applying too much power?
I've screwed up two correctly adjusted and maintained Sachs Spectro 7 hubs by pedal power alone. I used that model because it was considered generally stronger than Shimano Nexus 7.
As far as symptoms, there are three that tend to indicate total failure:
1) nasty noises, often followed by
2) freewheeling in both directions and/or
3) pedal lockup
Most gearhubs aren't even rated for tandem use, so using motor assist through the gears is asking for trouble. As far as I know, the Rohloff is rated for 2500W gross power, the NuVinci N171 is rated for 5000W, and the NuVinci N360 is rated for 2000W. All the others are rated for one person's leg power, as long as the one person doesn't exceed their weight limit.