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The Ultimate Guide to E-bike kit hub motors

The Ultimate Guide to E-bike kit hub motors
Issue Time:2015-12-28

  - our Direct-Drive motors are now all High-Torque 6x9 wound, so they run slower (approximately 15mph at 36v or 20mph at 48v), and our Geared Motors have been replaced by a 500w version, (approximately 20mph at 36v or 28mph at 48v). The Direct-Drive is now our Heavy-Duty motor and the Geared motor is our performance motor. The 350w geared motor is available in limited quantities at a significant discount, as they are being discontinued.

Quieter or more torque? More durable or less drag?

The first set ofanswers corresponds to direct drive motors: they're quieter, but have lesstorque, they're more durable, but they're also heavier and drag some, makingpedaling less efficient, and their range on a full charge is a little less. Directdrive motors are nearly silent, humming along smoothly. In contrast, gearedmotors make some whirring noises, but are so light and small they could almostpass for a normal bike hub, and there's almost no drag when pedaling, andthough they offer more torque, letting you climb hills quickly and acceleratefrom stop lights like nameless doped-up ex-racers, the nylon gears can wear outunder hard use.

What nylon gears? Direct who? Thereason you've got a choice at all is because there are two basic ways to getmotor power from the hub to the wheel. Let’s look a little closer:

The Direct Drive Motor


The 500w Direct-Drive motor is simple and robust

The direct drive motor (photo aboveright) is the simplest: the outer shell of the hub is part of the motor, andhas a big ring of strong rare-earth magnets fixed to it. When the motor runs,it drives the wheel directly. That's where your name comes from. Thismeans that the wheel is simply a motor with the shaft fixed in place so thatthe body of the motor (the outer hub shell, and thus your wheel) spins insteadof the shaft. It’s a simple system, but the motor has to be big and heavy toproduce enough power - a small motor spinning slowly doesn’t produce enoughtorque, and the speed you want your wheel to turn at is relatively slow, so themotor needs to be as big as possible to produce torque at low speeds, or elseyou could add some gears to change that….


 

The Geared Motor


The 500w Geared motor: light, high-torque, and fast.

The geared motor (below) is a littlemore complex, but the clever complexity makes it lighter and smaller. Gears areawesome, you already have gearing on your bike - it can turn a bunch oflow-torque circles into a few high-torque circles, or the reverse - this is handyif you've got a tiny motor and you want to make it push along a loaded bike, sothe motor runs at high speed for efficiency and the gearing slows it down andincreases the torque, to push you forward. And just like the gearing on yourbike, a ratcheting freewheel lets you coast without drag (in this case from themagnets), but the extra moving parts will eventually wear, just like the gearson a bike will some day crunch and skip and slip, and you'll have to replacethem (the nylon gears). And since the gearing is small and designed to make awheel spin fast, heavier riders and riders with a lot of cargo will havetrouble with durability. For people that need a really strong push, specialdirect-drive trike hubs with the motors wound (using more copper) for highertorque and a lower top speed will make pulling heavier loads a breeze, they’llgo slower, but they’ll give lots of power and should last for many years.

Complete Specifications forE-BikeKit motors


The 500w Geared (left) is smaller and lighter than the heavy-duty moredurable Direct-Drive motor (right).

Direct-drive500-1000w "heavy duty":
Brushless DCelectric motor
3 phaseoperation with 5 hall sensors
9 pinproprietary connector
6x9 windinghigh-torque
Direct drivewith permanent rare-earth magnets Sealed cartridge bearings on both sidesSecondary shaft seals on both sides 15mph typical top speed in 26" wheelat 36 volts / 22 amps 20mph typical top speed in 26" wheel at 48 volts /22 amps 600lb total Approx 0.38mph per volt at 20"
500w designedpower rating
792 wattsnominal peak power under typical conditions (36v battery, 22 amp controller)
1056 watts maxrecommended peak power (48v battery, 22 amp controller) ISO 6-bolt disc brakecompatible 100mm / 135mm Rear motor option over-locknut width 135mm Standardfreewheel gear compatible Front over-locknut width 100mm

 

 

Geared 500-1000w"performance":
Brushless DCelectric motor
3 phaseoperation with 5 hall sensors
9 pinproprietary connector
10x6 windinghigh-speed
Internallygeared drive with permanent rare-earth magnets
3-to-1 planetarygearing with steel sun gear and steel outer ring gear, and 3 nylon planetarygears Internal ratcheting clutch disengages motor to reduce magnetic drag whencoasting (regen physically not possible) Sealed cartridge bearings on bothsides  20mph typical top speed in 26" wheel at 36 volts / 22 amps28mph typical top speed in 26" wheel at 48 volts / 22 amps  300lbtotal
Approx 0.5mphper volt at 20"
500w designedpower rating
792 wattsnominal peak power under typical conditions (36v battery, 22 amp controller)
1056 watts maxrecommended peak power (48v battery, 22 amp controller) Iso 6-bolt disc brakecompatible 100mm / 135mm Rear motor option over-locknut width 135mm Standardfreewheel gear compatible
Frontover-locknut width 100mm

 

Geared 350-750w:
Brushless DCelectric motor
3 phaseoperation with 5 hall sensors
9 pinproprietary connector
10x6 windinghigh-speed
Internallygeared drive with permanent rare-earth magnets
3-to-1 planetarygearing with steel sun gear and steel outer ring gear, and 3 nylon planetarygears Internal ratcheting clutch disengages motor to reduce magnetic drag whencoasting (regen physically not possible) Sealed cartridge bearings on bothsides  20mph typical top speed in 26" wheel at 36 volts / 22 amps28mph typical top speed in 26" wheel at 48 volts / 22 amps  200lbtotal
Approx 0.5mphper volt at 20"
350w designedpower rating. Not recommended for 48v usage or heavy loads
792 wattsnominal peak power under typical conditions (36v battery, 22 amp controller)
1056 watts maxrecommended peak power (48v battery, 22 amp controller) Iso 6-bolt disc brakecompatible 100mm / 135mm Rear motor option over-locknut width 135mm Standardfreewheel gear compatible
Frontover-locknut width 100mm