Leafmotor

In the subsection of section Classification of electric bikes we looked at options for motors used in electric bicycles, their positive and negative sides.

Let’s try to analyze and compare the characteristics of electric motors (bldc hub motor and bldc stepper motor)from one well-known manufacturers: Leaf Motor (China).

Leaf Motor produces sets with a motor-wheels, and the other kits that use a chain drive.
The analysis will be based on data from well-known owners of electric bikes site EValbum, the characteristics of the manufacturer, and other sources on the Internet. Therefore all figures are approximate, and the findings are an expression of opinion ePowerBikes.ru

As stated by bldc hub motor, voltage motor-wheel independent maximum speed:24V – 25 km / h, 36V – 32 km / h, 48 V – 50 km / h. These data are confirmed by practical measurements elektrovelosipedistov. The maximum velocity at the start line set bldc stepper with 42 km / h and end with 120 km / h. Those cyclists who speed up to 30 miles is enough, can choose a motor-wheel 24V,36V,or 48V.

For practical information, electric bikes with a motor-wheel 36V 500W and lithium-phosphate battery 10Ach a maximum speed of 32 km / h and can cover a distance of 50 km. For those who want to ‘fly’ at speeds above 50 km / h, suitable set of Leafmotor 601kit-1 48V 1000W e bike kit.

Compare sets with the same maximum speed – 45 km / h – a new set 601kit-1 48V 1000W bldc hub motor and bldc stepper 48V 500W. Based on the characteristics of graphs,we choose the rate at which engines operate most efficiently, it is 40 km / h for both.

For the same power consumption in this mode – 420-440 watts, at the time of bldc stepper motor is a little more, but this is neglected. It turns out that energy costs are the same at a speed of 40 km / h. We obtain a theoretical figure 10.5 Wh / km, although in practice the number is likely to be greater. Now suppose that we face a steep hill. The maximum torque developed HBL hub motor – 30 Nm, bldc stepper motor – 38 Nm.

For the calculation we use a calculator elektrovelosipedista. Let Curb weight of a bicycle with the stepper motor – 100 kg, the rise of 7% of 3.5 km. To overcome this recovery time is needed more than 26 Nm on the wheel 26. ” Power expended by the motor-wheels 601kit-1 e bike kit is more than 1060 W at a speed of 35 km / h. Total energy costs – 106 Wh.

What makes it with bldc stepper-kit? He switched to the lowest gear, increasing time and decreasing the rate of 2.4 times (for cassettes with a maximum star 34t). At 2600 revs / min, torque on the shaft of the gearbox – 11 lb lost by power – 390 watts, speed – 14.5 km / h. Cost of energy to overcome lift – 94 Wh. Switching gears allow the rider to use the bldc stepper with the maximum efficiency of ~ 83% versus 73% for motor-wheels 601kit-1. As you know, the availability of transmission system for a bicycle greatly expands the range of effective use of a set of bldc stepper motor. These are one of the best available right now,s o if your´re looking for one, check it out. 9-14 cassette on the wheel 26 “will change the torque of 6 to 60 Nm and a speed in the range of 11.5-45 km / h (about 2100-2900 revs / min) at an efficiency of above 80% (included efficiency gearbox and chain drive). Efficiency of the motor-wheels 601kit-1 has a maximum value of 78% of torque 10-16 Nm.

It is logical that upon arrival at the ideal surface Bonneville Salt Lake in Utah, at 40 km / h, both test sets will spend the same amount of energy. But as soon as the trial will move to an area with hilly terrain, a set of bldc stepper will be more economical than 601kit-1, and of course will be able to overcome the ups who his opponent will not under force.

We note again that the higher efficiency is achieved when using leafmotor’s bldc stepper motor in the range of maximum efficiency, extended thanks to gear bike.