Quote:
Originally Posted by Ecky
A geared motor shouldn't need a clutch, I would imagine. Not quite zero resistance but certainly a lot less than a direct drive.
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I need it so that I don't have to pedal with the cogging torque losses when it shuts off over a set speed. The geared hub motor I want will have more cogging torque than the direct drive Leafbike in my custom build because it has thicker laminations. That cogging torque makes a big difference in how easy it is to pedal. The Milan only needs 150W of pedaling to do 30 mph, and the cogging losses of a MAC motor would likely be around 50W at that speed. If I have a clutch to decouple it, those losses are no longer a concern. This means the GMAC sold by Grin is not an option, since that is fixed with no clutch. That extra 50W would increase my speed to 35 mph on flat ground.
The idea being, that I could have a "street legal" ebike in most of the U.S. that can go well over the 28 mph Level 3 e-assist limit on flat ground and down hill while 100% human powered, but the motor will be available for accelerations and hills.
In Missouri, my custom build is legal due to a technicality in the legal code, but that may change next year. In Illinois, I have to limit it to 750W/28 mph to be legal. If I get a geared hub motor with a clutch on the Milan, I'll have all the assist I need for hills, AND be able to cruise at 35-40 mph most of the time, and be legal in most of the U.S. because the motor will shut off at the speed the law says it must.
In order to take the custom build apart for rebuilding/redesigning it, I need to get this Milan usable for the same purpose.
I'm eventually going to build a new shell for the KMX based on the Milan, add a roll cage, make some custom spindles that can accommodate cotter pin axles, add a rear shock, have Mitas MC2 moped tires all around, and turn it into a pedal "car" of sorts that can do 100+ mph, but still be pedaled to 40+ mph in a sprint with the motor disabled. This one won't quite be legal, but I'm going to have everything hidden so well no one will be able to tell it has a motor without taking it apart. I want to make a transportation appliance that gets around 20 Wh/mi at 70 mph, and can do 0-60 mph in 5 seconds or less.
Eventually, my plan is to build a completely custom platform dependent upon the success of this project, one that can accommodate a pure unmotorized velomobile of about 70 lbs, a "street legal" e-assist velomobile of about 85 lbs, an illegal high performance e-assist velomobile of about 100 lbs, and an AWD sports car with more than one horsepower per pound of vehicle with no bicycle parts of about 120 lbs.