Over the years I have been ask to create a page that shows everything we have learned about converting standard bikes to electric bikes. The only reason I have not taken up this task in the past is because of time limitations. The following will include what standards we use in accepting bikes for conversion, a step by step of how we convert bikes to electric, the tools we use and how to use them, every thing we know about the Bafang mid drive system, the lithium ion battery, and the laws that have authority over the use of electric bikes. I hope this will be helpful.
Thanks for visiting our site,
Alvin Carpenter, PhD
Dr. A.L. Carpenter
Who will be riding the bike we convert to electric?
When someone brings a bike to our shop for conversion we want to know as much as we can about the rider of the bike as well as the bike itself. The bike is a static, non-living, object whose value ( other than its artistic value) comes into being when it becomes one with the rider. Therefore, it is Rider first and bicycle second.
The who question is a question of responsibility. I have been ask to build electric bikes for children as young a seven. Of course that would not be wise as even the mildest electric motor would be hazardous to one who has yet developed skills that are required to manage an electric bike.
We also take into account the maturity of the rider. The Wild West approach to electric bikes is behind us as we enter a world of regulations. The Federal and State guidelines regarding electric bikes are for the good of the entire cycling community. These guidelines protect both the riders and the general public.
Prior to accepting a bike for conversion we try to estimate the age of the rider as it pertains to the ability to manage an electric powered bike. Again, it is a matter of responsibility on our part to determine if a persons age will affect their ability to ride an electric powered bike.
Age is not always a limiting factor when someone comes to our shop requesting their bike be converted to electric. We have converted bikes to electric for at least a dozen riders over 90 years of age within the last two years. Albeit, all of these riders have a long history of cycling and are very experienced cyclists. Some have cycled around the globe and across the US several times. Others are former racers. This group of elders may have many decades behind them yet they are athletes in body and soul. In addition, their collected knowledge of cycling throughout the years under diverse conditions is encyclopedic. Their bikes are always well maintained and may even be of a different era but they always make for great eBike conversions due to their fantastic condition.
The point is, electric bikes will not pose a danger to a rider over 80 who is an experienced rider in great shape. And, as we all know, there are some who are 80 plus who are in better shape than some of us much younger.
We have built electric bikes for many who have recovered, or are recovering, from major life changes (for lack of a better term). Electric bikes provide the opportunity of outdoor exercise, and just to be able to get out and enjoy the day. I will not go into the long list of physical conditions that can severely impact ones mobility but I do know the following: Cycling can improve someone mood if not anything else. If someones' mood changes for the better, their outlook improves. If their outlook improves they are happier and happier people heal quicker. One thing about electric bikes is that they make people smile. Myself, our mechanics and staff have see many times over how people smile when they return from their first ride on an electric bike. Sometimes I think we are not selling electric bikes...we are selling smiles.
When a bike is brought to us for conversion we always take into account the experience of the rider. This is very important as all electric bikes are similar to low powered motorcycles. Some of the steps we take to insure the rider is going to be safe on their new electric bike is setting the power level commensurate with the skill of the rider, and making changes to the bike itself.
One of the advantages of using the Bafang mid drive motor system is it allows us to set the parameters of the motor. For example, a stock BBS02b 750 watt motor is set at 25 amps. By adjusting the amps from 25 down to 18 we have effectively limited the output of the motor to 500 watts. This does two things. First, it tones down the power of the motor and it becomes more manageable. Second, it extends the range of the battery. In fact, riders of all levels prefer to set the amps at 18 in order to increase their range. I am often ask, "At 500 watts will I lose much power?" No, hardly so much you would notice. Remember, in all of Europe the standard motor allowed by law is 250 watts so a 500 watt motor should be all one would need for most riders and riding conditions.
Considering known limitations
A man with dementia came to our shop and said he wanted us to convert his bike to electric because he kept falling off the bike every time he stopped pedaling. He thought converting it to electric would solve his problem. Of course the problem was not the bike and converting it to electric would not be the solution.
Another day, a man and his wife came to our shop and he wanted to test one of our electric bikes. He seemed very angry. I put him on one of our bikes and stepped outside with his wife to watch him ride. He could not ride in a straight line. I looked at her and said, "Ma'am, I'm sorry but your husband should not be on any bike much less an electric bike." She agreed and said, "He had a stroke not long ago and he just wants to ride a bike again."
We do not refuse to convert bikes to electric often but when we do it is for good reason.
Changing the bike to fit the needs of the rider
All bikes are adaptive to the rider. We can make any bike a safer bike, a more comfortable bike, a faster bike, or a slower bike. We do all of these at our shop but the most important thing we do for riders of limited ability or experience is to make their bike safer. We start with the tires. The tires on a bike are the foremost safety feature, even more so than the brakes. A bike tire is the only contact the bike has with the surface. If a tire fails the whole system fails with it.
All tires have a "contact patch." A contact patch is that small portion of tire that is in contact with the road at any given time. The larger the contact patch the quicker the bike can slow to a controlled stop without going into a skid. A large contact patch also allows more absorption of shock and offers higher resistance to punctures. In other words, wide tires are the single best upgrade to any bike being converted to an electric bike.
Installing wider tires is the best thing a rider can do to make their bike a safer bike once it is converted to electric.
Every bike, without exception, goes through three intensive inspections. The first inspection is when the bike arrives. When a bike arrives we go over the bike looking for the obvious.If there is nothing obvious we except the bike for conversion. A second inspection happens during a thorough cleaning of the bike. This "hands one" cleaning allows for an inspection of the spokes, tires, rims, frame and fork. The third inspection occurs after the bike is dissembled and is on the work stand. The third inspection is the most comprehensive. It is here that we search for hairline cracks in the frame, inspect the dropouts, the integrity of the fork/bars/stem and headset. At that time, if there is nothing that would prohibit the conversion of the bike to electric, we proceed. If there is a safety issue the first step is to see if it can be corrected. If the bike cannot be made safe to convert to an electric bike, we reassemble the bike, tune it up and return to the owner at no charge.
Remember, electric bikes can be fast and powerful. A hidden flaw in bike will be amplified under the power of an electric motor. When we do these inspections...it is always with the rider in mind. Again, it is always people first, bikes second.
Some bikes are so poorly constructed that they should never be converted to electric. Just about everything about these department store bikes are such low quality they rarely last longer than a year. These bikes are not a poor candidate for conversion to electric, as they are not a candidate at all. There are very few bike shops that will work on these bikes because they are not worth repairing. One time I was talked into converting one of these bikes to electric by the owner who insisted it was his favorite bike and how he would care for it after conversion. I relented (mistake) and converted his bike to electric. After the bike I was finished I tentatively took it on its test ride and thought "Ye gads." The owner picked up the bike and thanked me enthusiastically. Within 24 hours the bike was back in my shop. The motor pulled the rear wheel right out of the drops.
Another time a man brought his favorite bike in to have it converted and I gave him as honest appraisal of the bike as I could. Everything on the bike was either broken or rusted so bad it hardly recognizable. I said to hime, "Yes, we can convert it but we would have to replace the wheels, tires, derailleur, chain, shifter, cassette, cables, cable housing, entire brake system, front fork, and the frame." He laughed and said, "Yeah, I suppose it is in pretty rough shape."
To be a good bike mechanic one has to possess a fairly comprehensive knowledge of the history of bikes. In the past, many reputable bike companies sold bikes that at some point began to fail. These failures could be very dangerous and often involved either the frame and/fork. All good bike companies like to explore new ways of building a better bike. This is a hallmark of the better bicycle companies. However, these innovations may fail after being used by a number of cyclists over a period of time. It does not happen often but it does happen it is important that the bikes/frames/components be recalled. A good bike mechanic needs to always be on the lookout for recalled components on any bike he/she is working on. More than once we had to pick up the phone to call a client and inform that their front fork had been recalled. If the recall is still active we assist our client in getting a replacement.
There are very few bikes we cannot convert to electric due to the original design of the frame or essential parts of a frame. For example, every now and then we will see a bike where the drive side chainstay is offset to the degree we cannot fit a motor. This is rare, but we do see it now and again. There are also some full suspension bikes where the pivot points would be impacted by the motor and thus cannot be converted. When converting bikes to electric we are very good at modifications but we do not make any modifications that affect the integrity of a weld of any type. Modification to any superfluous parts such as chain guards and bash guards, in order to install the motor is not a problem as they are not integral to the bike frame.
We hate to say..."Sorry, but it would not be a good idea to convert your bike to electric due to....." However, it is far easier to say no to a client than having to say "I am sorry" after the bike failed causing loss and injury. Last week we were ask to install a 1000 watt Bafang mid drive motor on a bike with a three speed internal hub. The rider weighed 300 pounds and he wanted to use the bike to climb hills. We told him that the power of the motor would destroy the three speed internally geared hub did not have a low gear sufficient for those specifications. In the end we saved him a lot of money and frustration.
There are many types of bikes that we convert to electric. This is not a compete list but here are some examples: Road bikes, mountain bikes, hybrid bikes, folding bikes, cargo bikes, beach cruisers, and vintage bikes.
Frame material: Frame material on a bike may be steel, aluminum, carbon fiber or titanium. The best material to work with is aluminum. The reason why aluminum is the best material is because of the larger shaped tubes. A large flat downtube is perfect for attaching the battery. Whereas, steel frames often have round tubes. We have come up with different methods with attaching a flat battery base plate to a round steel downtube but it is not easy. This is important as a solid connection between the battery and the frame is essential.
What is the best bike to convert to electric? The easy answer is to say "Your current bike." After all, your current bike is one that you purchased because you like the bike, it fits you well, it is comfortable, you are used to riding it, so why not choose that bike to convert?
However, it may be the best bike for you under human power but may be a terrible match for the power of an electric motor. When you look at a bike that is being considered to be converted to electric the first thing you look at is the ability of the bike frame to accommodate large tires. The larger the tire the safer the bike...period. This is not a debatable point. If your favorite bike can only accommodate 23mm tires then it will not make the best electric bike. We have converted more than a few of these bikes and we know the ride is rough, due to the low air volume and high inflation of the tires, and the contact patch is just too small to provide a safe controlled stop. Electric bikes with 23-25mm tires should only be ridden by experienced cyclists.
In addition your bike may be an unfavorable candidate due to condition. When I say condition I do not mean the usual wear that comes from riding the bike. Any bike that is regularly ridden will show wear and some more than others. I mean those bikes that have been stored under the house for the last 30 years and now all the parts have been rusted together. We have seen this more than you would think.
An interesting thing about electric bike conversions is that a used bike works just as well as a new bike and costs significantly less. The reason for this is simple. A bicycle frame, fork, shifters and derailleurs can last for decades and the same goes for a good set of wheels. The "perishables" on a bike are relatively inexpensive. A new chain, cassette, and shifter, if needed, would cost less than a $100. If you do not have a bike to convert to electric, or the bike you have is not a good candidate for conversion, then give some thought to a used bike. Bicycle Blue Book, in San Jose California, (online at Bicyclebluebook.com) is a good source, or your local Craig's List. Remember, when it comes to converting a bike to electric think simple. The Bafang motor delivers a lot of power so a 7 - 9 speed bike is plenty of gear choices to get you up the hills.
Places to find a great used bike:
For new bikes at a great discount try:
The speed of a bike refers to the number of cogs on the cassette. A seven speed bike has seven cogs, an eight speed bikes has eight cogs, all the way up to twelve speed bikes. Back in the 70's we had a bike called a ten speed bike. Actually, it was a five speed bike with a double chainring.
Electric bikes work fine with as low as 6 speeds and do not need anything over 9 speeds. In fact, many times when converting a 11-12 speed bikes we have to lock out the last cogs because the chainline is so far off kilter.
Chains for 6-8 speed bikes are very strong and come with 7.1 or 7.3mm pins. Nine speed chains are also very strong. It is when we have a 10, 11, or 12 speed chains do we start to worry. Ten speed chains are narrow, the pins are smaller, the plates are thinner and if one is not careful these narrow chains can snap under the power of an electric motor.
If a bike is a 11 or 12 speed then we strongly recommend using an eBike rated chain. An eBike rated chain is almost twice the cost of a standard chain but a standard chain is just not strong enough to handle the torque of the Bafang mid drive motor.
In conclusion, bikes with 7, 8 and 9 speeds is all you would ever need for an electric bike. If your bike is 9 or 10 speed it will work just fine. If your bike is 11 or 12 speed an eBike chainset is needed.
Do road bikes make good candidates for conversions? When you look at the "Big Four" bicycle companies (Giant, Cannondale, Specialized, and Trek) you will see nearly all of the electric bikes they produce are not built on the road bike platform. The same is true for all other bicycle companies. Why would that be the case? First let's look at the negatives. Road bikes traditionally have drop bars. The purpose of drop bars is not for comfort (far be it), they are for aerodynamics. One thing you never have to worry about with electric bikes is aerodynamics. On an electric bike you can sit tall in the saddle and ride into a headwind without any effort.
Another negative is the size of a tire that can be fitted to a road bike is between 25mm and 28mm. These are narrow tires. These narrow tires are inflated to 100-120 psi and make for a very harsh ride. Also, the narrow tires have a very small contact patch. A contact patch is the portion of a tire that is in contact with the surface at all time. The part of the tire that is on the surface is the only thing that allows us to come to a controlled stop without entering into a skid. A small contact patch will put a bike into a skid much sooner than wide tires.
The reason why road bikes use small, narrow tires is they are light and give better rolling resistance. However, electric bikes are not bothered by heavier tires or rolling resistance as it has the power to overcome what would be obstacles to human powered bikes.
We have converted many road bikes into electric bikes and we try to fit them with the largest tires the bike will allow. Sometimes our clients will have us remove the drop bars and replace them with a flat bars. The flat bar allows for a more upright position.
We are often ask if we convert carbon fiber bikes to electric. The answer is always "depends." Many carbon fiber road bikes lay up the carbon fiber very heavy in the bottom bracket area. This is done to make for a stiff bottom bracket. The bottom bracket shell area must be stiff for the efficient transfer of power. The thickness of the carbon fiber on the bottom bracket shell will determine if a Bafang mid drive motor will fit.
In my opinion...road bikes can be converted to electric and they can be ridden safely...but they cannot take advantage of wide tires, upright riding position, and front suspension, all of which are a plus for any electric bike.
As an aside, road bikes were the only bike I would ride until I was introduced to the eBike. A electric bike meant I no longer needed drop bars (for less wind resistance) and skinny tires (for better rolling resistance) as these things no longer mattered on a powered bike. Electric bikes allowed me for the first time to ride in an upright position, on large tires with front suspension. Now when I go riding it is always on an eBike because it has made bike riding a more enjoyable form of transportation and recreation.
Most, not all, mountain bikes make for the best electric bike conversions. A mountain bike has a strong frameset, is able to accommodate large tires, rider sits in an upright position, has flat bars, and has some form of suspension.
There are two types of mountain bikes. The first is called the "hard tail." The hard tail mountain bike means there is only suspension in the front of the bike. A hard tail mountain bike makes for an excellent conversion as there is plenty of room to install the battery. The bike in the picture above is a hard tail mountain bike.
This is a picture of a full suspension bike that we built for a client. A full suspension bike provides an incredible ride in terms of comfort. However, there are full suspension bikes that are very difficult to convert due to limited area for battery placement. Here, we inverted a side load battery in order to fit the small area on the downtube.
The full suspension bike must be of good quality and in good condition otherwise the power of the Bafang motor will cause the bike to compress the suspension upon acceleration. The rear of a poorly made full suspension bike will twist under acceleration. That said, a well made full suspension bike makes for a great conversion as long as there is room for the battery.
Hybrid bikes are more of a road bike than a mountain bike as most do not have any suspension. In fact, if you put drop bars on a hybrid bike you would have the classic road bike. Typically, hybrid bikes are designed to accommodate larger tires (38-45mm) and have attachments for racks, front and rear. Because of the ability to use larger tires and has a flat bar for an upright riding position, all hybrid bikes make for good conversions to electric.
A hybrid bike conversion to electric will be faster than the mountain bike conversion because it is lighter and has tires that are narrower. Therefore, one always has to be careful when accelerating. One of the things w do to reduce power in some bikes, is to reduce the amps from 25 to 18. Not only does it slow the bike a bit but it also extends the range per charge considerably.
We have converted many cargo bikes to electric and all of them made for perfect conversion to electric. Most people would think a cargo bike would be difficult to convert, given its size. Just the opposite! Cargo bikes have plenty of spaces for a battery and they have a lot of room for the routing of cables. People love the cargo bikes we convert to electric as it makes it so much easier for them to carry children, groceries, cargo of any kind up long hills.
A beach cruiser is a bike that has a strong frame, balloon tires, fenders, and have between one and seven gears. These are very simple bikes and it is this lack of complex shifting that makes them popular. They are good candidates for conversion because of the large tires, and ample room for the battery. Even though there may be a limited number of gear choices, an electric bike does not need a wide array of gears. Only bikes under human power need 10,11,12 speed bikes. In fact, a 7 speed bike is plenty of gear choice for the power of the Bafang motor.
Fatbikes (one word) are bikes that have massive tires. These tires range from 4 1/2 to 5 inches. Now...the question is; Are these bikes a good candidate for conversion to electric? Let's start with the negatives. First, these bikes can be very heavy. Weight of this magnitude will effect the range of the bike. For example, a 48v 13Ah battery on a hybrid bike may get 50 miles per charge...on a fatbike it may get only 30 miles per charge. Second, the rolling resistance of these tires is considerable and this also will effect range. Lastly, the tires are so wide the chainstays are wider than any other type of bike. Wide chainstays mean the bottom bracket must be between 100 and 120mm! These large bottom brackets mean the motor has to have an extended axle which is more expensive and heavier than the standard 68-73mm axle.
The positive sided of the equation is...these bikes are a blast to ride after conversion to electric. With those massive tires it sound like a truck coming down the road. ANd, they are super comfortable.
Have you ever ridden an adult trike? I am surprised they are sold to the public. The problem with these types of bikes is that they want to tip over every time you turn the bars. Unless you travel very slow these bikes are a hazard when it comes to cornering.
If you put a motor on an adult tricycle you amplify the tipping effect. We get a lot of requests to put motors on adult trikes but unless it is a special case we try to convince our client that it is pretty much a bad idea. Unless a person plans to ride in a straight line an electric powered trike can be dangerous.
The irony is a person seeking an electric powered trike is someone doing it with a thought of safety. The thinking is three wheels will be more stable than two. Of course, in this case it is just the opposite.
As an alternative, we recommend finding a step through bike, no top tube, that is easy to get on and off the bike. For example the Specialized Roll.
A bike with large tires and a step through frame can be a great alternative to an adult trike.
We have built a number of tandem bikes and so far so good. Our biggest concern is the total weight of the riders and the bike itself. If each rider weighs 200-250 pounds, and the bike 65 pounds and the plan is to climb hills I think the motor will not be sufficient. That said, we have yet to have a single failure on any tandem we have built.
It must be remembered, all electric motors have their limit and to exceed that limit for any duration of time will literally melt the insulation of the wiring on the motor until it shorts out.
If there is any motor capable of powering a tandem bike it is the Bafang mid drive but we must never forget that even the powerful; Bafang motor has its limits.
We love converting recumbents to electric! So far we have been able to successfully convert every recumbent that has come our way. We have a working relationship with T-Cycle to provide us with brilliantly engineered battery mounts and other accessories that make the transition from a standard recumbent to an electric recumbent a possibility for any recumbent trike.
A Class I electric bike is an electric bike that does not have a throttle and the motor cuts off at 20 mph. The power of a Class I electric bike cannot exceed 750 watts. The Class I bike is allowed anywhere a standard bicycle is allowed including bike paths.
The Class I electric bike offers a lot of advantages over the Class II and III in terms of safety, greater range per battery charge, longevity of the motor, and much easier on the drive train of the bike.
A Class II electric bike is an electric bike that does have a throttle and the motor cuts off at 20 mph. The power of a Class II electric bike cannot exceed 750 watts. The Class II bike is allowed anywhere a standard bicycle is allowed except bike paths.
Disadvantages of a throttle include; Reduced range per battery charge, wears out the drive train of the bike (chain/cassette), not allowed on public bike paths or most organized rides.
A Class III electric bike is an electric bike that does not have a throttle and the motor cuts off at 28 mph. The power of a Class III electric bike cannot exceed 750 watts. The Class III bike is allowed anywhere a standard bicycle is allowed except bike paths.
This is the most popular choice as it provides the performance needed when required. On some rides you just might need that extra bit of power. In a race in Pescadero, California I was off the back of the peloton when I saw something out of the corner of my eye. From an adjacent field came a large, loping coyote heading right for me. Well, I am still here to tell the story but I know from experience that sometimes a little bit of extra power can get you out of a tight spot.
As one can see, in the State of California it is legal to have a throttle on an electric bike but under what conditions is having throttled powered bike a good idea? For those who are not able to pedal a bike, for any reason, the throttle powered bike is a godsend. The throttle allows some to continue to enjoy riding a bike regardless of infirmity that has stopped them from riding a standard bicycle.
We have seen far too many mechanical problems associated with throttles to give them a thumbs up for every rider. A Bafang 750w motor delivers a lot of power and that is great for climbing hills or carrying heavy loads. However, when one uses the throttle to propel the bike forward from a dead stop that same power can snap a chain or even burn up the motor.
There is a reason why all major bicycle companies do not have throttles on their bikes and that is they can be unsafe, and can easily damage the bike.
There are two types of throttles available for Bafang Mid drive motors. The twist throttle is of such poor quality we have never offered it as an option. The second type is the thumb throttle. There are two types of thumb throttles. The above is the heavy duty thumb throttle.
Throttles on an electric bike are dangerous as they are easily activated. The throttle is like a on/off switch. If someone touches it, or leans against it...the bike takes off with or without the rider.
Many times we have seen people say "What's this?" as they toggle the throttle and activate the motor. Before anyone tests one of our bikes the first thing we say is, "This is the throttle and if you touch it it will activate the motor so please be careful."
There is a difference between a bike lane and a bike path. The picture above is a bike path. A bike lane is the marked lane on a public road that is for bicycles. All electric bikes can use a bike lane but a bike path can be used by electric bike if they do not have a throttle.
Electric bikes are now being used on organized century rides and Grand Fondo's. However, most of them specifically state that electric bikes with throttles are not allowed.
Throttles on electric bikes are probably not the best idea for all the reasons described above and should be limited to those who really need them. If properly used a throttle can be safe and even useful in certain conditions. If a throttle is improperly used a lot of things can go wrong. Therein lay the dilemma.
The Bafang color is known throughout the world. When you attend a Trade Show you look for the big orange sign and you know you have found the Bafang booth. First, I am going to provide a link to the company itself and let them tell you a bit about their products. Bafang Motor Company
Now let's take at look at the Bafang factory where the motors are made. Bafang Factory Tour
The Bafang company sells over 1,000,000 motors a year and is the largest manufacturer of electric bike motors in the world. It might be noted that Bafang was first named 8Fun motors and that is why you still see the word "8Fun" stamped on some crankarms, and chainring covers. 8Fun is an odd name to the ears of Westerners. The number eight has always been the number of good luck, or good fortune and the word "fun" is a reference to direction and when used together it means: Good fortune in eight (many) directions. Makes sense when you think about it. Wherever this motor takes you, may it bring you good fortune.
Easy question. If anyone show me a better motor at any price point I will switch to the other motor, Still waiting....sound of crickets....
We have converted over 700 bikes to electric at the time of this writing and we have seen only two motors burn out and it was not the fault of the motor...it was the fault of the riders. Both times it was a rider climbing a hill using the throttle in the highest gear.
These motors are simple and yet very powerful. Believe it or not, there is around 20 parts to this motor. It is very simple in design and because of this simplicity there are not a lot that can go wrong. Simplicity always trumps complexity and that can be applied to just about everything.
The Bafang mid drive is so powerful we constantly have to adjust the power to the rider. The motor is so reliable we offer a one year no fault warranty. It is a safe bet for us because we know the exact failure rate of these motors and it is zero.
This is a Bafang BBS02b 750 watt motor.
Weight: 8 pound
System voltage: 48v
Power output: 750 watts nominal
Power output Peak: 1150 watts
Maximum current: 25 amps
Throttle and peddle assist
electric brake equipped
Shift sensor equipped
The Bafang BBS02b 750 watt motor will fit the riding needs of 90% of riders. Remember, the maximum size motor allowed in Europe is 250 watts and in Canada it is 500 watts. A 750 watt motor is triple that allowed in Europe and if that does not supply the necessary power for an electric bike then nothing will. Remember, anything over 750 watts is illegal for use on any public road in America.
This is the Bafang BBSHD 1000 watt motor. The "HD" designation means heavy duty.
Weight: 12 pound
System voltage: 48v
Power output: 1000 watts nominal
Power output Peak: 1500 watts
Maximum current: 30 amps
Throttle and peddle assist
electric brake equipped
Shift sensor equipped
The Bafang BBSHD 1000 watt is a heavy duty motor for off road use. This motor sheds heat better than the BBS02 750 watt motor but is also heavy, slower, and more expensive than the BBS02 750 watt motor. We always recommend the BBS02 because it is lighter, cost less, and is legal for road use.
People always ask what kind of maintenance they need to do on their Bafang mid drive motor and the answer is...nothing. There is nothing you can do other than ride the bike and enjoy the power and simplicity of this motor.
Some like to open the case of the motor and add grease to the gears but that is not necessary. Also, there are some who replace the nylon gears with metal gears thinking it will make the motor last longer. It will not make the motor last longer...it will just make it noisier.
For those who like to tear down their motors and replace the parts it is a fairly simple process. They are not like combustible engines, they are electric motors and every part can be replaced at some point.
If we ever find a better motor we will use it on our conversions. The genius lies in the simplicity of the Bafang motor. Every other electric mid drive motor we have opened up is complex and complexity always leads to complex failure that cannot be remedied by the local bike mechanic. When a Bafang mid drive comes into our shop for repair it is usually something like the speed sensor magnet is out of line, the brake lever motor cutoff is out of line, sometimes a display may fail, but the motor itself is pretty much fail proof if it i s not abused.