Update on Bafang BB02 crank drive.

Discussion in 'Electric Bicycles' started by motorbikemike45, Aug 21, 2014.

  1. I have used a couple of hub motors(9 Continent units), both in front and rear wheels. The Bafang is my first center drive unit. I have a Bafang BB02, 36 volt, 500 Watt unit. The instalation is simple as pie, remove the crank unit and slide in the Bafang geared motor-crank unit, clamp it in place, add the crank arms, your pedals, do the simple wiring(the motor controller is in the motor housing), add the supplied brake levers, the computer unit, and the throttle and off you go. The throttle is touchy, it almost feels on-off at first, but with some practice, you soon learn to use it gently to control speed. After the frame on my green e-bike cracked, I transferred the unit to the red bike. The front shifter can't be used, as there is only one sprocket in the unit and there really isn't room for another one, or two, you also need the room on the bars for the throttle, etc. The seven speeds on the rear were plenty adequate with the power available. There are three levels of assist. Level 1 is good for riding on busy trails with bikes, walkers, skaters, and so on sharing the path. I rarely use level 2. Level 3 is the highest, and fastest, great for traveling alone on the side of the road.

    The first time I took off using the throttle and the acceleration was much faster than the hub motors, direct or geared. It felt much quicker accelerating than any other motored bike I've tried, gas or electric. Shifting up through the 7 speeds of the rear gears was great, up to the governed 19 MPH top speed, then it just seemed slow. I went back to the on-line site with instructions for the computer and discovered how to over-ride the governor. Top speed on the throttle is now 27 MPH. Acceleration is hot and top speed is fine, what more could you ask?

    I then discovered that if you turn on the power, but don't touch the throttle, you get an assist as you pedal. I use the assist when I am riding in a group, like Critical Mass. Using the assist and pedaling, I can pedal 10 or 15 times further than pedaling without assist. My bad knees normally crap out after 5 or 6 miles of pedaling. With assist, I can stay with the group as far as they wish to travel and my knees will still allow me to walk the next day. One problem with the assist mode is the power stays on for a second or so after you stop pedaling. It can be a little scary if you need to slow quickly, but the brake levers cut power whenever you squeeze them, even lightly, and you soon adapt.

    Range using WOT is about 2/3 of what I was getting using a direct drive hub motor. The price I pay for the greatly increased performance. Using the assist mode while pedaling, I haven't reached the end of the battery. The range is very long on assisted pedaling and I may never reach the end.

    I think this is the best e-bike I have had to date. Using the throttle only gives outstanding performance and the range pedaling in the assist mode is great. You can also simply use the bike as a pedal bike. The motor does add some drag, but less than a hub motor. The Bafang center drive unit weighs a tad more than a geared hub motor, but less than a direct drive hub motor. I am very satisfied. Four stars.
    pbeggs and cpuaid like this.

  2. cpuaid

    cpuaid Member

    Mike, do you think you can get 13 miles range out of the batteries in peddle assist mode at a steady 19-20 mph?
  3. I will never know. At the highest assist level I might get to 19-20 mph for a second or two. I'm a 69 year old man with bad knees. I can easily pedal(with assist) a sustained speed of 10-14 mph. Anything beyond that is only in my memory. Extrapolating the range I can get with WOT powered riding, yes, that should be easily do-able. My battery is a Ping 36 volt, 20 Amp Hour battery that weighs in at a hefty 16.5 pounds, so the range with the direct drive hub motor was 35 miles when the battery was new. The battery is now 3 years old and I use the e-bike all the time, so the battery range has started going down. I got 28 miles per charge on the old battery with the direct drive drive hub motor before I replaced it with the Bafang. My next e-bike set up will likely be a 36 Volt, 10 Amp Hour battery powering a 350 Watt Bafang BB02 on my Specialized Expedition pedal bike with the NuVinci 360 hub.
  4. Sign Guy

    Sign Guy New Member

    Thanks for the update. Have you thought about getting a lithium battery? I know they are more money but the weight is probably quite a bit less. I'm looking at getting a kit so this helps in my research.
  5. Lithium-Iron-Potassium batteries may weigh slightly more than the same volt/amp hour rated lithium Ion battery, as the lithium Ion has a slightly higher energy density. I will stick with LiFePo4 as there are NO toxic materials in the battery, so disposal could be in a landfill, though I will always recycle them. Also, with lithium Ion there is always the possibility of fire or even explosion if you charge/discharge them over the safe rate. No such problem with LiFePo4. Ping LiFePo4 are my choice for now, though I Will likely go to a 36Volt, 10 amp Hour battery instead of the 20 amp Hour unit I'm using now. The 10 amp Hour unit weighs half as much and I'm getting to old to lift the very heavy e-bike.
  6. Sign Guy

    Sign Guy New Member

    Will the 10 amp battery cut your distance or speed down quite a bit? I'm looking at all these different options and am looking forward to getting my bike hooked up. I like the idea of the mid mount system and being able to switch gears. Not sure I want to spend a small fortune though. Seems like the batteries are the biggest expense in all this.