hill climbing ability ?

[poweron]

Hi !

I´m thinking about buying the 36V 500W Motor, but I don´t know if it has got enough power for my purpose.

I´ve got to go 20km, but the last 1km I got to go up a hill with gradients of up to 15-20%.
How much power has the motor in areas with low rpm ? I mean I know that I have to pedal, but do I feel the motor assist me, or only the extra weight making me slow ?

Is a hub-motor suitable for my purpose, or is it better to take one of these kits, which use the chain with the bikes gears ? Is anyone here with experience on these kits ?

thanks for your answers
andy

[OneEye]

Wow.  15-20% gradients are significant.  That is probably outside the limits of the 500W goldenmotor, unless you want to throw it in a 16" rim (and have a significantly reduced top speed) or something.  Might be looking for something along the lines of a Crystalite 5 series motor, or as you mentioned put something together that drives through the gears.  Pop on over to the Endless Sphere forums, they have a wider user base and some of them are operating on hills.  Ypedal, dogman, and pwbset are users that come to mind.  They are all hubmotor users.  I don't remember right now who is running a geared setup for hills, although with your commute that might be an advantageous setup to get you the hill climbing power and the higher top speed.

Thinking out loud: maybe run a 72V setup for the flats and then switch packs to parallel 36V with a higher current capacity for the hills on a hubmotor setup?  I don't know if anyone has tried that sort of thing or not.

[biohazardman]

The GM motor is not that great for steep hills with 26 inch wheels and tall tires although it will help you until you stall out completely. I have near 500 miles on mine now and live in Portland Oregon in the US of A with lots of hills though most, that I travel, are not that long.  The motor helps allot on these but won't do it by itself.  These are the kinds of hills only the most in shape cyclists will climb and I can do it now with the help. I would agree with OneEye if you want something to climb hill use a smaller wheel or get a geared motor hub or external you can over-volt for more help up the hills. Still it's good to know what you are getting as many of them are not rated correctly from what I have read. Some more info here to read  to help with your decision.

http://endless-sphere.com/forums/viewforum.php?f=4