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
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 managed 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 rider 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.
Now...the other side of the coin. Sometimes age is a very limiting factor. Three times this year (2020) I had to meet with the families of men who requested we convert their bike to electric. Each time I said the same thing; "I am sorry. but your (insert relation) should not be on any bike much less an electric bike." Those were difficult meetings but in each case the family members were in agreement. One time a spouse said to me , "Of course you are right but he would not accept the fact he should no longer be on a bike unless it came from a professional."
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 I am not selling electric bikes...I am 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 builders 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. The 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 grasp 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. Bike manufacturers like to innovate, build bikes that are cutting edge, experiment, as that is what leads to all discovery. Sometimes the innovations fail years after they have been introduced to the public. All builder, and bike mechanics have to keep a keen eye out for the recalled bikes and bike components.
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.
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, tandems, folding bikes, cargo bikes, recumbents, adult tricycles, beach cruisers, and vintage bikes. All of these bikes may be made of aluminum, steel, titanium, or carbon fiber. Of all of the bikes there some that are very difficult to convert to electric and some that are much easier. But the question is...which type of bike makes for the best conversion?
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 to convert? Because 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 bike that is being converted to electric the first thing you consider 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.
Your bike may be an unfavorable candidate due to condition. When I say condition I do not mean wear that comes from riding the bike. Any bike that is regularly ridden will show wear. 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.
The absolute best bike for conversion is your current bike if your current bike is one that we can certify as safe when we are finished. If, and only if, we can unequivocally say, "This electric bike is safe for responsible riding."
It is difficult for us to say someones bike would be unsafe were we to convert it to electric because we know people have a surreal attachment to their bike, and for good reason. Fortunately, people understand safety and are always in agreement with our assessment when we explain why their bike may not be the best bike.
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.
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 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 1-2 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. Eleven and twelve speed chains are narrower still and that is when we should seriously consider using a eBike chain.
An eBike chain is one specifically made to be used on an electric bike and they are costly. Typically the eBike chain is made of high tensile steel.
In conclusion, bikes with 7, 8 and 9 speeds is all you would ever need for an electric bike.
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 too electric 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.
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. Also, full suspension bikes have pivot points that cannot come into contact with any part of the motor. Lastly...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 a 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.
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 I 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 I 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 very things 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 and it is zero.
Bafang makes many different types of electric bike motors, too many to list in my limited space. The motors that are the most popular are the BBS02b 750 watt motor and the Bafang BBSHD 1000 watt motor. Bafang also makes a 250 watt motor and a 500 watt motor.
The European maximal allowable electric bike wattage is 250. In Canada the maximal allowable wattage is 500. In the US the maximal allowable watts for road use is 750 and for off road it is 1000+ watts or higher.
There is little demand for the BBS02b 500 watt motor in the US. The BBS02b 500 watt is the same as the BBS02b 750 watt motor with the exception of the number of amps . The 750 watt motor is set at 25 amps whereas the BBS02 500 watt motor is set at 18 amps.
Nearly all Bafang midrive motors in the US will be either the BBSHD 1000 watt or the BBS02b 750 watt.
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
First, let it be said there is a lot of misinformation online regarding the BBS02 750 watt motor and the BBSHD 1000 watt motor. Most of this erroneous information comes from the resellers of Bafang motors.
We have built hundreds of bikes using both motors, and we test ride them all. It can be stated unequivocally that the Bafang BBS02b 750 watt motor out performs the BBSHD 1000 watt motor.
The BBS02 is lighter, faster, less expensive, powerful, and meets the needs of 90% of all riders. There should not even be a market for the BBSHD but there is and the HD outsells the BBS02.
The only reason why the BBSHD 1000 is promoted by resellers as a better motor is the profit margin is higher.
Secondly, the BBSHD is illegal on all public roads in the United States, Europe and Canada. Every bicycle that has a motor in excess of 750 watts (one horse power) is classified as an unlicensed motor vehicle when on public roads. Does this matter? Yes, it can effect you insurance rate if cited and you bike can be seized. Also, in case of an accident your insurance company may not provide any coverage due to the fact you are on an unlicensed motor vehicle on a public road.
We have installed the BBS02 750 watt motor on many cargo bikes. Some of these bikes carry heavy loads up steep hills and we have not had a single motor failure. One of our cargo bikes with the 750 watt motor carries 450 pounds.
One last word: Perspective. Remember, all of Europe is limited to 250 watts. With 250 watts their electric bikes climb hills and carry heavy loads and everyone seems satisfied with the performance of their electric bike. In the US we have triple the power and feel it is insufficient.
Ok...one more "one last word." The BBS02 750 is faster than the BBSHD 1000. Again, we know because we test ride all the bikes we build and the BBS02 is faster. The BBSHD is sluggish until it slowly builds speed and by that time the 02 is long gone.
Ok....one more last word...promise. The BBS02 can run on any 48-52v battery with any BMS card. Whereas, the BBSHD cannot run on any battery with a BMS card of less than 30amps as it can damage the motor. Also, the BBSHD simply does not like 52v batteries while the BBS02 seems to run fine with the 52v. Every order I place with my battery company there is a note at the bottom of the invoice and it says, "Please do not use 52 volt batteries with the Bafang BBSHD motor."
In summery, I agree one motor is better...and it is not the BBSHD 1000 watt motor...it is the do it all, incredibly powerful, lightweight, inexpensive, legal for pubic roads, BBS02 750 watt motor.
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
This motor is heavy, expensive, sluggish, and illegal for road use in all 50 States. It is also illegal on all bike paths. Yet, I sell and install this motor on a regular basis. Why? Because it is generally promoted on the internet as a better motor. It isn't.
Question: Why did Bafang develop a motor that cannot be used on any public roads anywhere in the world (some exceptions of course). The answer is simple. There will always be the perception that bigger is better. However, making some bigger does not make it better it just makes it more expensive.
With the Bafang 750 there was nowhere else to go as it is pretty much the perfect motor. Some may prefer metal gears instead of the nylon gears but there is good reason for the nylon gears in the BBS02 (and the BBSHD). Nylon gears run quiet and will last years unless the motor is abused. We have never seen a single failure of any of these nylon gears on the bikes we have built with the BBSO2 or the BBSHD.
Will a BBSHD have more top speed than the BBS02? One time I rode a BBSHD equipped mountain bike with a 52T chainring up to 44 miles per hour. I am not sure I could do that on a BBS02 equipped bike but how often are you going to want to ride a bicycle at 44mph? How long will the tires withstand the heat at those speeds and what sort of protection will your get from a standard bicycle helmet? Personally, any speed over 25 miles per hour on a bike is quite enough as the potential for an accident and injury increases and is not worth the thrill of speed.
Is the BBSHD the motor best for off road use? I think it is too heavy for off road use. This is a heavy motor and when you add the weight of the motor along with the weight of the battery you have a total of 22 additional pounds to a bike you are climbing hills with. Falling is a part of off road riding and this is too much weight to have falling on the rider.
Point: Electric off road mountain bike racing is now sanctioned by USAC and other racing groups. The limit on the size of the motor is 250 watts, There is no 1000 watt division.If mountain bike racers can compete with lightweight 250 watt motors then I am not sure why a 1000 watt motor would be necessary for off road use.
In conclusion, if this were the California State Fair and we were judging the "Best Electric Bike Motor," I would give the blue ribbon to the Bafang BBS02 750 watt motor. It is truly the do it all motor, in every category.
This is a typical hub motor. Hub motors like these are found on every poorly made bike in the world. Hub motors are used on electric bikes for one reason and that is because they are very inexpensive. If one peruses eBay, Amazon, Aliexpress, or Alibaba, one would find thousands of electric bikes for sale at unbelievable low prices and they all have one thing in common...a hub motor.
Many electric bike companies that sell their electric bikes online at incredibly low prices also have a hub motor on their bikes. One of things that is always missing from their promotional material is the weight of their hub motor electric bikes. They omit the weight of the bike because they are very heavy due to the hub motor. At our shop, the number one complaint we hear about hub motor driven electric bikes is weight and a lack of power.
It is not an exaggeration to say that millions of electric bikes are produced throughout the world with a hub motor. As a manufacturer of electric bikes we are contacted weekly by Asian eBike companies asking us to buy these hub motor electric bikes with our logo on the frames. We politely refuse and tell them we will stay with the reliable, lightweight Bafang mid drive.
It has been said that I do not like hub drive electric bikes because I am a retailer of Bafang mid drive motors. First, I am not a retailer of Bafang motors. In fact, at Island City Bikes we do not sell anything to the general public. Our speciality is converting standard bikes into electric bikes using the best motor on the market and that happens to be the Bafang mid drive. We warranty the Bafang motor for one year...out of our own pocket. That is how confident we are in the reliability of the Bafang motor.
Are all hub motors bad? No, there is a wide spectrum of electric bike hub motors ranging from terrible to excellent. Some hub motors are small, lightweight, and of high quality. However these motors are very limited in power, torque and speed, and they can be triple the price of a Bafang mid drive. There are some riders who want to ride an electric bike but do not want to be seen riding an electric bike. That is the market the small hub motor dealer is looking to reach. Then there are the large high powered electric hub motors. These motors can go up to 3000 watts. Again, they are very, very heavy motors.
Here are the negatives of the hub motor:
1. Shipping is expensive as your have to ship an entire wheel. Or, you can order only the motor and have it laced into a rim when it arrives. However, that is expensive.
2. A front hub motor is dangerous. The motor can pull free of the dropouts on the front fork. In addition, most accidents that occur on a hub driven bike are those where the hub motor is on the front. Being "pulled" by an electric motor is very natural.
This is a dumping ground for electric bikes. There are many of these "electric bike graveyards" all over Asia. There are so many of them because China produces millions of electric bikes every year. One thing all these bikes have on common is they all have hub motors. It can be safely said that all poorly made, inexpensive bikes in the world have hub motors.
3. Hub motors are heavy...very heavy. Some electric bikes with hub motors weigh up to 70 pounds. The are some hub motors that are light but they are only 250 watts which is not enough power for climbing hills or carrying cargo. In my opinion, 250-350 watt is just to small of a motor for an electric bike.
4. Many (most) bike shops will not work on a bike with a hub motor. By work on I means no work at all, not ever repair a flat tire. The reason for this is the bikes are too heavy. A bike shop repair stand clamp is 5 feet off the ground. They would have to lift a 60 pound bike 5 feet to get it on the stand. Also, to repair a flat the whole hub motor has to be removed. These motors are bolted to the bike. A bike shop could easily charge $100 to repair a flat on a bike with a hub motor and be within their right to do so.
5. A rider cannot repair a flat while out on the road. If a rider has a flat on wheel with the hub motor the likelihood they can repair it on the road is pretty much zero. You would have to call for a truck or van to come retrieve the bike and then you would have to find a bike shop to repair the flat.
It is a many step process to remove a hub motor in order to fix a flat. First, you have to lift the bike off the ground or turn it upside down. That is impossible for most riders due to the weight of the bike. You have to carry wrenches as the wheel is bolted to the frame. You have to disconnect the cable from the motor to the battery. You have to muscle the bike out of the drop outs. Then you remove the tube and insert a new tube and get the wheel bak on the bike. The axle of a drop out motor has to line up with the drop outs or it will not go in. Once the wheel is in place, the power cables connected, the chain back on, and the bike righted then it is finished. Unless, the tube is pinched and in that case the tire will deflate and you will have to go through the entire process again.
6. Bikes with hub motors are so heavy they cannot be carried on standard bike racks for cars.
7. Hub motors are typically sealed and cannot be repaired.
8. Hub motors make it impossible to adjust the disk brake pads because the motor blocks access. Disk brake pad adjustment on a bike with a mid drive motor is a 5 minute job. That same task on a hub motor bike takes and hour....if you can find a bike shop willing to do the adjustment.
More bikes with hub motors...
A Stanford professor walked into my shop and ask me a few questions. After I answered he chuckled and said, "You are as opinionated in real life as you are on your website." I said, "I hope that is a good thing." He said of course it was as an opinion based on facts is different than a opinion based on hunches, feelings or intuition.
I see motors of all types come into the shop an we convert bikes to electric seven days a week...I know what motors underperform, fail, overheat, and are poorly constructed. To this day I have yet to meet a single person who did not regret purchasing a hub motor driven electric bike after one year ownership.
In conclusion, I have heard the saying going around the forums that, "Hub driven electric bikes are for those who cannot afford a mid drive." The Bafang mid drive does cost a bit more than a hub drive but it will provide years of trouble free performance.