The difference between what I had before and with the bionx system is about 14.5 lbs (the battery itself is between 9-10 lbs.) My prior setup was about 34 lbs (fenders, racks, brooks saddle, front hub dynamo, lights, heavier pedals, and some beefy 36 spoke wheels) and was not a lightweight bike by any means. I'm still under 50 lbs now which is slightly better than average for an off-the-shelf e-bike.

Maximum speed is 20 mph with pedal assist. I've been above 27 on a slight downhill... but the motor isn't helping beyond 20 mph.