City bike with Xiongda 2-speed

I converted my city bike to electric and thought I would share the results. I live in San Francisco and my daily commute requires climbing 12%-18% hills. After much research and advice from this board, I decided on a Xiongda 2-speed motor paired with Luna's 52V Mighty Mini battery. Here are the pics, and more details below.

Before:


After:
View attachment 3

I finished the build about a month ago, and I've been commuting by bike nearly every day since then. I am very pleased with the Xiongda motor. With the 52V battery, the motor tops out around 21mph (34kph), which is fast enough for me when biking on crowded city streets, and acceleration from standstill is great. My bike has an 8 speed gear hub, but most of the time I ride in either 4th or 8th gear. If I ever build another bike, I will probably switch to a single speed or 2 speed hub to save weight.

It really shines on hills, and I can climb up the steep hills (20%+) around my neighborhood in 4th gear without needing to stand or sweat. I still need to pedal, but the effort is similar to walking up the hill. I'm usually climbing around at 8mph-10mph. My daily commute is around 4 miles round trip, and I usually charge the battery once a week, give or take a day or two.

I ordered directly from Xiongda rather than Luna Cycle, because I wanted the option to ride without a display. As it turns out, the controller had a 6V output for powering lights, but it requires the display to control the lights. I ended up stashing the display, controller, and battery in a bag with a 3D printed bracket to so that the display is visible at a glance from inside the bag.

View attachment 2



I also wanted to remove the bag and electronics easily when locking the bike outside, so I consolidated all of the controller signal wires to a single 24 pin ATX power connector and the motor power wires to an MT60 connector.



This was my first bike build, and Bonnie at Xiongda was very helpful in answering my questions. I had a bike-savvy friend help with the wheelbuilding, the fork required stretching and shims to accommodate the disc brake, and I needed to do some dremel work to mount the PAS. Otherwise, the build went very smoothly.

Hope this writeup is helpful. Happy to answer any questions.

Love it! Did you install the 2-speed selector switch or do you just leave it locked into the low hill-climbing gear?

I installed the switch. By coincidence, it fit perfectly underneath the gear hub selector.

Very nice build! I like what you did with the wiring and the display. Top-notch work!

Well done. I would say that using this on such steep uphills is a real torture test. If the motor ever seems to be getting extra hot, the only cooling upgrade I have seen for a geared hub motor is to install a vent near the axle (to prevent pressure from building inside) and then add a coffee cups worth of automatic transmission fluid (ATF).

Of course this will cause some drips, but some builders in this situation would prefer to do this, rather then get a larger and more visible size of hubmotor. Do you ever get any comments? Is anyone surprised its a motor, or is it usually obvious when someone sees it?

It's very discreet. No one has commented on the motor, but I've gotten a few double-takes from other cyclists as I pass them on steep hills

Hi I also have the 2 speed with 52 mini on my bike Friday..my first motor died with 40 miles on it..Luna replaced..how many miles you got so far? I'm going to Sicily and have reliability anxiety..thanks

I'm just over 80 miles at this point. Hope you have better luck with the second motor.

How many miles do you get out of that battery with this setup?