Bafang E-bike Conversion Kit Design Deficiency

Its been about a year since I built my Bafang conversion e-bike and I still enjoy riding the bike. I am impressed with how powerful the 750 watt motor is and the range the 840wh battery provides. However, the Bafang conversion is missing one key feature that I’ve become very used to on my Bosch e-bike. That is a continuous range estimate on the control display. Without a range estimate provided by the e-bike system, you have to guess the range left in the battery based on your experience.

So it finally happened. I ran out of juice while riding the Bafang. I must admit it came as a surprise. I started the ride with 3 out of 5 bars displayed on the battery indicator. Three out of 5 bars means I should have somewhere between 40-60% of the battery’s charge left. However, after about a mile into my ride the battery dropped to 2 out of 5 bars meaning I had a 40% charge. Still, I wasn’t worried sine I was planning an out and back ride. I simply planned to turn around when, or before, I reached 1 bar. My plan was to use 1 bar going out and 1 bar to return. However things didn’t go as planned.

To my surprise, about 10 miles (16 km) out while climbing a hill the battery dropped to 1 bar. Only 10 miles (16km) on 1 bar? That was unusual. Still I wasn’t worried. I just turned around and headed home. If I used 1 bar going out the remaining bar should get me home. Right? Wrong! Only a few miles more while climbing a short steep hill the battery indicator started flashing empty. No way! I should get more than 15 miles (24 km) on a battery that was at least 40% charged when I started. Was the Battery Management System saving power to protect the battery from completely discharging? There was no way to tell. Not willing to take a chance on damaging my battery, I shut off the power and started pedaling my dead e-bike home unassisted. Luckily it wasn’t as hard as I expected. The motor didn’t add much drag and the additional weight was only noticeable on climbs. About half way home I turned on the system again. What was happening? The display showed 1 bar again and I was able to make it home on assistance level 1. In my opinion, not having a continuous range estimate is a BIG DESIGN DEFICIENCY in the Bafang system, especially when for some unknown reason the first half of a charged battery provides a lot more miles than the last half of the charge.

Ken Whittaker


How to program the Bafang BBS02 Controller

As I mentioned in my post Thumbs Up to Bafang!, one of the outstanding features of the Banfang BBS02 conversion kit is that it’s configurable by the user. Many changes like configuring the bike as a class 1, 2, or 3 and other basic features of the bike can easily be configured from the display.  However, with a laptop computer, a special USB programing cable and the Bafang Configuration Tool Software the Bafang motor controller can also be reprogramed by the user  to  improve the usability and performance of the e-bike.

My goal here is to only make you aware of the possibility of reprogramming capabilities of the Bafang controller.  Detailed instructions can  be found from other sources below:

  • However, be warned that reprogramming your Bafang system is not without risk. You can destroy the controller if done incorrectly.  So, read the guides  and do not attempt to customize your settings if you don’t fully understand what you are doing.  Proceed at your own risk.

Ken Whittaker


Build or Buy an E-bike?

Have you every wonder if it would be better to buy or build an e-bike? I have. So I built an e-bike using an old Cannondale road bike and a Bafang conversion kit. After I was done building the conversion bike, I used the lessons I learned to buy the most cost effective high quality e-bike that I could find at the time. Here are the results.

Cannondale Road Bike Conversion to E-bike with Bafang Kit

Conversion Kit

Motor: Bafang 750 watts

Class: Configurable as a class 1, 2, or 3

Battery: 840Watt Hour

Chainring: 1X 52T

Display: Bafang C961 LCD Display

Cost: $1,100 + Cost of Bicycle

Pros:

Prices – A Bafang conversion is a fraction of the cost even if a new bike is purchased for the conversion

Configurability – The Bafang can be configured as a class 1, 2, or 3 e-bike.

Power: The Bafang has a much larger motor and battery.

Factory Built Cannondale Synapse Neo 1 E-bike with Bosch Motor and Battery

Factory Built

Motor: Bosch Active Line Plus 350W

Class: Class 3 e-bike

Battery: 500Watt Hour Bosch PowerTube

Chainring: 2X 50/34T

Display: Bosch Purion

Cost: $3,799 – MSRP $4,725

Pros:

Gearing – The 2X Chainring with a 50/34T is a game changer for me. It gives a wide range of gears like my traditional bicycle.

Quality – The bike is designed as a system and fits seamlessly together.

Appearance – Likes likes a traditional bike.

Final Analysis: I’ve put hundreds of mile on both bikes and both are great e-bikes. So let your budget be your guide. The Bafang kit is very affordable but does need a little tinkering once in a while. The Cannondale Synapse Neo 1 with its Bosch system is a quality e-bike but considerably more expensive. In retrospect I should have used a bike with wider tires and disc brakes for the Bafang build considering its power, weight and speed.

Ken Whittaker


What Does it Cost to Charge an E-bike?

Charging an e-bike battery may not cost as much as you might think. To find the cost you need to know the specifics for your battery and the cost per kilowatt hour from your electric power provider. In my case, my battery is 48 Volts with a 17.5 Amp hour capacity and the cost of a kilowatt hour from my local electric power provider is about 12 cents. Here are the three easy steps used to calculate the cost of charging my battery.

  • Determine Battery Watt Hours Sometimes the battery watt hours are labeled on the battery. In my case it is labeled 840 Wh. However, if I didn’t know the watt hours I could calculate it by multiplying the volts by the amp hours. I have a 48 volt battery with a 17.5 amp hours capacity which equals 840 watt hours.
  • Convert Battery Watt Hours to Kilowatt Hours A kilowatt hour is a measure of electrical energy equivalent to a power consumption of 1,000 watts for 1 hour. So, 840 watt hours is equal to .840 kilowatt hours or 840 divided by 1,000.
  • Determine the Cost of a Full Charge Take the cost of a kilowatt hours from your electric power provider and multiply the kilowatt hours of the your battery. In my case, a kilowatt hour cost about $0.12 multiplied by .840 kilowatt hours battery equals about 10 cents to fully charge a flat battery.

For those who prefer to just plug and chug the numbers into a formula:

It is good to know that I am only consuming a few pennies worth of electric energy each time I ride my e-bike.

Ken Whittaker


Choosing an E-bike Battery

I want to tour with my e-bike so the range the battery will provide is a very important factor for me. Unfortunately, e-bike batteries can be the most confusing component of the bike. For example, my battery is a 48 Volt, 840Watt Hour, 17.5 Amp Hour battery. But what does that mean? While Bafang USA Direct states that it provides, “Up to 840-watt hours for an incredibly long range,” that really isn’t much help.

E-bike manufacturers tend to focus on watt hours. However, range cannot be determined by simply dividing a battery’s watt hours by the watts of the motor. Range will vary widely based on many factors including type of bicycle, rider posture, total weight, tires, riding speed, pedal assist level, terrain, riding surface, prevailing winds, etc. So while my battery might provide power for an hour running full blast on throttle, it may also provide assistance for 100 miles or more on assist level 1. Only experience will tell the true range of my bike and battery.

However, I have found a very useful tool for estimating the range of a motor and battery combination. While the site is Bosch specific, it can provide an idea of what range a motor and battery can provide under various conditions. Check it out at https://www.bosch-ebike.com/us/service/range-assistant/ or click here.

Ken Whittaker


Can You Get a Workout on an E-bike?

With the start of the new year generally come new resolutions to get more exercise and to lose some weight. But, can you do that on an e-bike? If you are more active with an e-bike than without, you should see some benefit. However, the question in my mind is it a worthwhile workout?  Unfortunately, that answer isn’t as clear because an e-bike can offer such a wide range of assistance. For example, at level 1 on my e-bike I’m doing most of the work and the motor providing about the same assistance as a good tailwind. However, at level 9 it is like riding an electric motorcycle with the motor doing most of the work.

Perhaps the best tip I can offer for maintaining or improving fitness with an e-bike is to use a heart rate monitor. Without a heart rate monitor it is very difficult to judge the intensity of the workout. Using a heart rate monitor I found that  I was getting a lot of aerobic exercise on my e-bike.  In fact, I was getting more aerobic exercise simply because I enjoyed the e-bike so much that I was riding my bike more. 

On the other hand, I also found that I wasn’t getting any anaerobic exercise on the e-bike because I was dialing up the assistance and zipping up the hills without putting in much effort.  To get a meaningful workout I have to calculate the heart rate and my intervals I want to maintain and adjust my e-bike assistance to get the workout I want.

If you are new to judging the intensity of your workout, here is an article by the Mayo Clinic,  Exercise intensity: How to measure it, that might help.

Ken Whittaker


Thumbs Up to Bafang!

One of the BIG advantages of the Bafang Conversion Kit is that it is configurable by the user, unlike my Bosch powered e-bike that can only be configured by an authorized dealer. As I’ve mentioned earlier, my current Bafang configuration is not compliant with the U.S. bike manufacturers’ and suppliers’ three e-bike classes. That said, I can easily reconfigure my bike to be completely compliant with a class 1, 2, or 3 bike.

For example, I live near the Torrey C. Brown Rail Trail that only allows Class 1 e-bikes on the trail. No problem, I can unplug and / or remove my throttle from my bike and limit the speed to 20 mph in the controller and I have a class 1 bike.

Similarly, I also ride my bike on the road in traffic where I sometimes feel much safer riding at the 28 mph limit for e-bikes . Again, with the throttle unplugged and / or removed, I can set the maximum speed in the controller to 28 mph and I have a class 3 bike.

Finally, if I want a Class 2 bike I can install the throttle, limit the speed to 20 mph in the controller and use only the throttle without pedaling and I would have a class 2 bike.

In my opinion, this is a big thumbs up for Bafang and a big thumbs down for manufacturers like Bosch. Manufacturers should not treat e-bike riders like children. Users should be free to configure their bikes to fit their needs and within the laws and regulations of the areas they ride. Otherwise, people will only find ways around needless restrictions with products like SPEEDBOX 3.0 for Bosch e-bikes or buy e-bikes from manufacturers that don’t impose unnecessary restrictions.

Ken Whittaker


Moving the Bafang Battery

As I posted earlier, I had to mount the battery on the rear rack because if I mounted it on the down tube I would have to give up both water bottle cages on my frame.  Since I couldn’t find an e-bike specific battery rack that would fit my battery, I need to fabricate my own. The battery is the most expensive component of my conversion kit. So, I wanted it to be super securely mounted on my rear rack.   

Initially, I bought the Wolf Tooth B-RAD 4 Mounting Base for this purpose. The B-RAD 4 is Wolf Tooth’s longest base with 9 threaded holes for ultimate flexibility.  While my original idea of using the B-RAD 4 on the rear rack worked well, I realized that the B-RAD Base would also give me the ability to precisely position the battery on the downtube.

Now, with the B-RAD 4 I’m able to move the battery to the downtube and still save the seat tube bottle cage.  In addition, my rather large 840WH battery is safely tucked inside the bicycle frame and approximately 9 lbs. of weigh was moved lower and more centered on the bike for improved handling.

Ken Whittaker


Bafang Integrated Lights

For enhanced safety I ride with my bike lights lit day and night. I notice that drivers are more likely to notice me and the speed that I’m traveling when I’m using lights. So I was delighted that Bafang integrated a 6 volt DC connection for lights on their motor – and that the lights can be turned on and off through the Bafang control display.

On the downside, the bafangusadirect website only offers a headlight and no taillight. Consequently, I had to find my lights elsewhere. This seems a bit short sighted of Bafang to ignore the road bike market needs by not offering a taillight. Hopefully Bafang will consider a taillight in future offerings.

A word of caution when considering e-bike lights. E-bike lights and dynamo lights are not the same. Unfortunately, I couldn’t find e-bike lights with a flashing option. I think that flashing lights are better for getting a driver’s attention during the day. If you know of any e-bike flashing lights, please let me know by leaving a comment below.

Ken Whittaker


Loose Bafang Motor

Another Bafang design flaw is the motor has a tendency to come loose. I experienced this problem several times within the first few hundred miles of riding. Bafang must be aware of the problem.  A google search on “bafang motor coming loose” will illustrate examples of the problem and offer many solutions.  

Caution fixing the problem. Initially, I simply tightened the fixing plate bolts to remedy the problem. Unfortunately, I didn’t use a torque wrench and the bolts have a specified torque of 10 newton meters. I over tightened the bolts and stripped the threads in the aluminum alloy motor casing. Needless to say now my repair became a much bigger job because I had to install a Helicoil in the motor casing to repair the damaged threads.

Left: Bafang Fixing Plate
Right: Stabilizer Bar

The best solution I found to fix the loose motor problem was to install a BSBF-1 Stabilizer Bar as an alternative to the Bafang fixing plate. The 3rd party Stabilizer Bar attaches to the chain stay of the bike with a hose clamp holding the motor solidly in place. However, I did rotate the stabilizer bar and clamped it to the seat tube to position the motor higher. For an nice clean installation, an M6 Rivnut and bolt can be used in place of the hose clamp.

Come on Bafang! If you see third parties fixing your design flaws to make your product workable, why not strive to make an outstanding product and fix the problem yourself?

Ken Whittaker