I am trying to find out if a 500watt motor connected to the drive chain like the Ecospeed motors will move 450 lbs up a 16% grade when using a NuVinci continuously variable gear hub. With out over powering the motor…that is I don’t see how the motor can run fast enough to keep from over heating. 2 or 3 mph will be enough for a trike but no less than 3mph for a bike with trailer.

I climb these hills with 400lbs less than 2mph, by leg power alone. I tried using Sheldon Browns gear calculator but it did don’t explain what the number are.


This is what I do with my legs and gears that I have.

18 front / 34 rear sprockets = 1 to .53 ratio .............
60 rpm’s at the crank x (.53) = 31.76wheel rpm's..............
62.8” circumference x 31.76 rpm's = 1994.82 ipm ..............
Divided by 12 = 166.235 fpm ..........
166.235 x 60 minutes = 9974.117 fph ............
Divided by 5280 = 1.889 mph.........

my blog is called 'commuter cycling technology' if any wants to see where I'm coming from.