ions82 wrote:I'm also curious about any updates, as well. I am considering the same setup (3220 & NV) for a future build. I think I read that the NV 360 is supposed to handle 98 ft-lb and be safe up to 1,000 RPM. I'm not 100% sure, but I thought that I remember it having the same specs as the 171. Of course, maybe they were both underrated and just had the same numbers slapped on them. I'm hoping that my next build will be somewhere in the 3-4 Kw range. If there are any updates for this project, please post!
N171/B features 8 torque transfering planetary spheres and is rated for 65 Nm (48 lb-ft) sustained input torque, 130 Nm (96 lb-ft) instantaneous input torque rating (published Here
N360 features 6 torque transfering planetary spheres of the same diameter as far as I can tell. Torque specs not published. Reasoning then would suggest that the N360 has at most 3/4 of the N171 torque rating (although likely lower due to the reduced positional radii of the planet spheres and their contact with the input/output discs). BUT....... the built in slippage clutch is designed to slip before the spheres & drive/driven discs to protect them from galling due to breakthrough of the friction fluid. So, we could make an assumption that the clutch slip threshold is proportionally similar, but its still only a guess until someone measures it.
My practical experience with the N360 is that I can get the clutch to slip with heavy pedalling alone in the underdrive ratios quite repeatedly which doesn't give confidence for high electrical power being added. However, being that electric motors apply smooth torque delivery rather than high peak-torque pulsating pedal strokes, there would definately be some a margin for electric assistance, just probably not more than a few hundred Watts. In any case the clutch should protect the drivetrain for the most part, so dont be afraid to find the limits and report back.
BTW though, A friend has a staton-Inc 4-stroke, N171B build pushing ~3kw that he has never had hub slippage problems with, so if your pushing high power id go with that.