My DIY Luna Cycle Bafang HD is finished!

Tom@WashDC

Active Member
Region
USA
City
Loudoun County, VA
Ok, Finally finished the project. Hit a few few small snags of my own making along the way. The kit was an easy install, nothing difficult. I took my time and tried to make a very clean and finished product.

One thing I did not want was a bunch of exposed zip ties on the frame, so I ran the main motor wiring harness through the base of the downtube up to the handlebars. I used grommets to seal the holes. After drilling any holes in the steel frame I used primer paint on the exposed metal, then painted again with black gloss paint. I wrapped some of the wiring with spiral wrap.

To eliminate exposed zip ties in the Speed Sensor install, I took a page from my Aventon Level e-bike and installed small zip tie holders mounted under or inside the bottom rail. Holders and screws are were primed and painted gloss black.

To manage the the battery, motor, and Shift sensor cable, I installed the seat post mounted controller box as a junction box. The battery to motor connections were coated in dielectric grease, and sealed with shrink tube and zip ties before closing the box.

A buddy of mine has the older version of the Bafang BBS02 motor and one of the problems that he and others have encountered is that the motor develops some play over time because the Bafang mounting bracket Bracket does not work perfectly. The new motor has the same bracket. In theory the bracket has small protrusions on the bracket side that mates to the bottom bracket. These protrusion are meant to "bite" into the bottom bracket when tightened. This should prevent the motor from moving, in theory. Evidence shows that the design is flawed and the motor/bracket develops play over time. My solution was to place a stainless steel hose clamp around the motor housing, and interlock it to a stainless steel hose clamp on the downtube. Both clamps were primed and painted. The clamp on the down tube sits on a rubber gasket covering the down tube. It may need tightening a few times as it may stretch. My future solution is to remove the motor bracket, and "pre-cut" grooves into the bottom bracket so the motor bracket protrusions can work as intended.

For the battery mount, I installed two additional anchor points in addition to the existing bottle bosses. I Installed two Aluminum Rivnuts, or Rivet Nuts into the downtube. I did not have a Rivnut tool, but I used a simple method I found in this YouTube video.

I have the Luna, 30 Tooth Mighty Mini chain ring, which I will install after my first real test drive. I reworked the brakes, adjusted the new Shimano Trigger Shifter, charged the battery, turned the system on, and everything worked seamlessly. Took it for a quick spin up and down the street. Works like a charm. The bike is much more powerful than my rear hub Aventon Level, which is an excellent bike. I will perform a major "off-road" test this week and get it covered in mud. ~Tom
 

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Tom@WashDC

Active Member
Region
USA
City
Loudoun County, VA
Took the bike out today for the first time with the stock Bafang chain ring. Through mud and up and down a lot if steep hills. Rides tight, feels so sturdy, like a tank. The tires made everything feel like butter. No problem in the deep mud, soggy grass, and ice n' mud covered fields. The Dolomite cable disc brakes work perfectly fine. Not as good as the hydraulics on my Aventon Level, but sufficient stopping power for my applications. Broke the stock Mongoose chain goin up a 100 ft., 50 degree grassy hill. Luckily I had a chain tool. Tomorrow I will test out the Luna Mighty Mini 30 tooth chain ring. Ordered a new chain. No fun fixing those things in the cold.
 
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jangles

Active Member
True Thomas , I only use the stock ring that comes with the BBSHD but have thought about something like a Lekke to get more torque . Speed is not really an issue but nice for some people .
 

Tom@WashDC

Active Member
Region
USA
City
Loudoun County, VA
So I tried the 30 tooth mighty mini. There is a huge difference just pedaling the bike. I did not take if for a a long run. Tomorrow I am going in the backwoods to give it a real test drive. My first impression is that on my 7 Speed cassette, I could do way with a few gears, maybe keep the smallest, middle and largest gear. The others gears seem superfluous. Definitely adds a a lot more torque for uphill's. There is some loss of top end speed but I don't care about that. My Aventon does 32 MPH which is really too fast and I don't see the need for that kind of speed in the off road conditions I intend for this bike.
 

Tom@WashDC

Active Member
Region
USA
City
Loudoun County, VA
Took the new build out for a hard, 3 hour spin through the woods, over hill and dale, through the mud, rocks, creeks, and fields of Loudoun County Virginia. Rode like a charm. I don't think I could ever go back to "skinny" tires again. The fat tires are so smooth. I did not have any problem with the rocks and obstacles in the path and felt I had lots of control. I really enjoy them on the pavement too. The Luna 30 tooth mighty mini chain ring has awesome torque, but the problem is I have to pedal like a jack rabbit at 16mph now! I will need to install a new rear cassette to give me a smaller gear so I can travel at 20mph without pedaling like a mad man. The build turned out exactly as I had hoped for. It will go pretty much anywhere, climb any hill with ease, and is very sure footed. I am a Fat Tire Bike fan now, and the Bafang HD was an easy install and has as much power as I could ever want. The Mongoose Dolomite is an excellent, inexpensive platform, and the brakes work fine. Eventually I'll add hydraulic disc brakes, but I'm in no hurry. I ran with 10psi on the front tires and 20 psi on rear tires, and a Suntour suspension seat post. I have a front suspension fork arriving in a few days. The ride was very smooth. I did the same ride (much slower) on my Aventon Level just once (never again) and the ride was much harsher even with a front suspension fork.
 

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Tom@WashDC

Active Member
Region
USA
City
Loudoun County, VA
Oooh! hand warmer cowels. Did you invent those? Never seen such a thing. 🥰
Got them off of Amazon. The first set I purchased (Zosen) were made of neoprene and they work well but are a bit snug, and seem delicate. The set (Kemimoto) in the picture are very durable, have lots of room, and are insulated with fleece. I used to use the same thing when kayaking in the winter. I prefer these "pogies" or handlebar mitts to gloves as my hands are free, and they stay very warm without gloves, even in the coldest weather. Just noticed that Rad Power Bikes is selling the mitts too: https://www.radpowerbikes.com/products/handlebar-mitts
 
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Tom@WashDC

Active Member
Region
USA
City
Loudoun County, VA
Very useful. But $79 is silly. I have had several pair as well. I found $20-$25 is all I need to spend!
I agree, that $80 is steep. My $20.00 Neoprene ones work just fine. I ended up getting two sets because my wife decided to become a cold weather rider too.
 
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Tom@WashDC

Active Member
Region
USA
City
Loudoun County, VA
Took the bike out yesterday for the hardest ride of my life. Racing through trails, and tearing up hills and banks like I was surfing Cape Hatteras the day after a hurricane (in my younger years 1975-85'). The motor is smooth as silk, and had power to spare. The Mighty Mini Chain Ring is "torque-city" on the hills. With Fat Tires I feel like I can go anywhere. My buddy and I (he rides a Bafang BBS02) were glad that our faces were hidden by cold weather masks as we must have looked like a bunch of teenage ruffians tearing up the neighborhood. I'm 62 and he is 59. This bike is way too much fun, and I have not come close to maxing out it's capabilities. As my buddy said to me, "it's just fun, like being a kid again with my new Big Wheel".

..and towards the end of our ride, as I was cruising on smooth, paved trails, escorting my buddy home, I got a friggin' flat tire, four miles from my home, and it stated to rain, nice and cold... Happy New Year!
 

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Tom@WashDC

Active Member
Region
USA
City
Loudoun County, VA
And for those that might be interested, the Mongoose Dolomite has a decent wheel liner!
 

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