I think that with a very hilly area you live in, then a bottom Bracket motor that replaces the front crank and chainring is the best option as it can use the 10 gears of the driven front wheel cassette, so you have a 10 speed Electric Bike, instead of a
single speed hub motor Electric bike,that the motor is only efficient(81%) at a narrow speed range of 30 to 34 kph for a 700C wheel!
I had a direct drive Golden Motor Magic Pie 3 500 watt 20" (406) rear wheel(7.5 kg) with a 36V 10Ahr battery, with the controller built into the motor so very tidy wiring, on a trike, then a Cruzbike Softrider V1, and it was great on flat roads up to 2% grade and had a 30 km range sitting on 20 kph (max efficiency of 81% at , but as soon as I went up a 3 to 5% grade of less than 1 km, then the range reduced to 15 km.
I fitted a motor current and voltage monitor, and the current went through the roof over 2% grade, OR when taking off from stationary, under electric assistance!
The direct drive hub claimed to recharge the battery on descents, but with the current meter, it was only 10% efficient, AND if you flattened the battery due to riding up any hills, the ride home was REALLY hard work as there was at least a 20 to 30 watts extra load to turn the motor! This is where a freewheeling geared hub drive OR Bottom bracket mid drive motor is better!
I looked at the geared hub motor, but with an External controller, the wiring was very messy and not watertight.
I recommend the Banfang BBS-001 36V 500w 25 amp built in controller Mid-drive kit, with Colour display, brake cable switch and thumb speed control($584 from California Ebike, $695 E-Bikes San Francisco, )
https://california-ebike.com/shop/bafang-8fun-bbs0102-mid-drive-bundle/
The 36V 500 w motor kit is $584, but with a max efficiency speed of
78 rpm (82% effic.) (243 W), max power
67 rpm (72%) (510w), Max Torque 54 rpm (68%) (470 w)
The 48V 750 w motor kit is $584, but with a max efficiency speed of
106 rpm (85% effic.) (470W), max power
90 rpm (76%) (930w), Max Torque 65 rpm (70%) (820 w)
It is easier to pedal between 67 and 80 rpm, than 90 and 106 rpm, with 175 mm long cranks!
With a 36V 14 Ahr (504Watt.hr) battery with on/off/locked keyed switch, and a 2 amp charger ($429 if bought separately, ($354 if bought with motor)
https://california-ebike.com/product-category/batteries/
The battery (362 mm long) will just fit upside down under the Silvio V1.5 frame between the front and rear wheels,where the frame bag is!
Also recommended is the gear sensor ($50), that cuts power for 0.5 sec when it senses a gear cable movement, so you don't have up to 500 w power during a gear change!
AND a smaller (36T) and lighter Leikke Thick/Thin tooth chainring, than the std. steel 44T, ($80), so a top speed of 32 Kph (20 MPH) @ 80 RPM crank using the 11T cassette sprocket, and 10 Kph (6.2 MPH) @ 80 RPM crank using the 36T cassette sprocket .
AND a hidden brake cable switch for a brifter brake ($20)
Total component prise of $1088.
The Bafang mid drive comes standard with 3 levels of pedal assist, but California E bike, can reprogram it to 9 levels from 20 watts up to 300 watts, so while pedalling the accurate level of assistance is maintained, and stops when you stop pedalling, so you do not need to keep your thumb on the throttle, ALL the time that you need assistance!
The throttle will give 50% max assistance when ever it is activated!
Contact California E bike, for an Electric Bike Dealer near you, to install the kit!
