Re: Leaf / leafmotor / leafbike high efficiency 1500w motor
Posted: Aug 23 2019 4:54pm
Has the efficiency of these caught up with the Leafbike motor yet? What about hysteresis and cogging losses? A few years ago when I researched these motors I remember them being not so great and the Leafbike being the best on the market. I'm now guessing the product landscape has changed a bit.
I highly value the ability to pedal the bike with the motor off and battery drained. It is of utmost importance that the vehicle's ability to move be independent of the electric drive. Effort required for a given cruising speed in pedal-only mode has to be comparable to a normal velomobile; I can tolerate increased mass and increased inertia losses during acceleration vs a normal velomobile, and a small loss in mechanical efficiency from the pedals to the rear wheel, but a good steady state cruising efficiency that doesn't feel like it is a labor to pedal the vehicle when the motor is disabled is what is desired. The Mitas MC2 moped tires, even though they are "low rolling resistance", may prove to be too lossy to pedal efficiently, but that will be something I have to try for myself since the data I seek doesn't exist in the public domain.
It would be nice if someone made a hubmotor with 95%+ efficiency and a weight of under 8 lbs. The technology IS there for such a thing. If only I had the tools to professionally build a motor from scratch... I suppose I could always do like Cedric Lynch during his youth and spend hundreds of hours to make a highly compromised but still functioning prototype of what I have in mind using basic tools laying around the house. It would take a few tries at my friend's shop to get the axle and freehub placement correct so that it would actually work on a bicycle's dropouts and for the gears/chainline to line up properly for it all to function. Have to start from somewhere though...