What it means to convert a bike to electric

Alvin Carpenter, CEO Island City Bikes, LLC

When a bike arrives in our shop for conversion to an electric bike we view it far more than an exchange of services and goods for financial compensation. We view it as a responsibility and a trusted relationship. I do not say that as a matter of marketing babble but in sincerity. When you place your bicycle in our hands the unspoken message is, "I trust you to transform my bike into a safe, reliable method of transportation for years to come." Every build is personal. We never let any bike leave the workshop that cannot be defined as a "safe, reliable method of transportation for years to come." 


Our work does not end when we return your bike to you fully built into a powerful electric mode of transportation. The relationship of trust and responsibility that began at our first meeting will extend into the future. We stand behind our craftsmanship and our product and will always be here if you need us.


Below are some, not all, of the steps a bike will go through to convert it to electric. Every bike we convert to electric we test on the roads of Alameda. Because we ride every bike we build we know the single most important part of any bike (car or motorcycle), is the tires. The only contact you have with the road is a very small "contact patch" of the tire. It is our professional opinion that all electric bikes should have, for the purpose of safety and comfort, the largest tires within reason. Electric bikes move at higher sustained speeds than a standard bike. These higher speeds require tires with air volume sufficient to absorb the shock from road debris, and obstacles seen and unseen. In addition, tires must be large enough to provide adequate traction for all surface types and conditions.


Stock tires, found on most bikes when purchased new, should be replaced. If possible, all replacement tires should be with e-Bike rated tires.

Isabella bike mechanic at Island City Bikes, Alameda CAlifornia

Meet Isabella one of bike mechanics and former pro racer.

The Process of Converting Your Bike to an eBike

Receiving the Bike

Disassembly of the Bike

Receiving the Bike

image21

Without candor I say that every bike that arrives in our shop for conversion creates a sense of excitement. The reason is that we love bikes, working on bikes, transforming bikes into electric bikes and most importantly...taking a bike and reconditioning it back into its original condition. To us, it is very rewarding work. Many times we have taken bikes to convert to electric knowing from the very start we would lose money but we cannot resist the challenge. The experience we gain by these difficult projects is what makes us the best in the business. 


To our knowledge, there is no company  that has converted more bikes to electric than Island City Bikes. Today, there are over 2,000 different bike brands each producing different models that vary from year to year. We have built a comprehensive database of converting many of these bikes to electric. Transforming a standard bike to electric takes knowledge, and experience; both of which carries equal value. 

Cleaning the Bike

Disassembly of the Bike

Receiving the Bike

cleaning the biker

Cleaning a bike is imperative for a thorough inspection of the bike. It is not possible to accurately inspect any bike until the bike is completely free of dirt, grease, or other contaminants. What we are looking for is damage to the frame, broken spokes, broken or worn components that would fail under power, missing parts, poor rim tape, cracks in stem or faceplate, worn tires, worn brake pads, or rims worn beyond their safe use. We do not consider rust on a bike as a poor candidate. In fact many of the bikes we have successfully converted were previously in storage and showed signs of rust. Sometimes, a lot of rust. Rust is not that difficult to remove and as long as it has not compromised the frame it is not a problem.




Disassembly of the Bike

Disassembly of the Bike

Disassembly of the Bike

Disassembly of the bike

When we convert a bike to electric we do not simply inset a motor, attach a battery, wrap the cables around the seat post and say, "It's done." We dissemble the bike and prepare each part for service. For example, the wheels are removed to gain access to the brake pads. The tires are removed to insure sufficient rim tape. The derailleur is removed in order to check and realign the derailleur hanger. The crank arms, chain, brake levers, shifters are all removed for cleaning and/or in preparation for the motor installation. In fact, in our opinion it is not possible to convert a bike to electric without  completely disassembling the bike. A bike that has been converted to electric has to be done in a manner that assures all parts function harmoniously. Therefore, every part is cleaned, inspected and repaired or replaced if necessary.


Does all this cost extra? No...it is our responsibility to built you a safe electric bike.

Ultrasonic Cleaning

Evaluating Derailleurs for eBikes

Disassembly of the Bike

ultra sonic cleaning of bike parts

This is a commercial grade ultrasonic cleaner. Ultrasonic cleaners use high pressure sound waves to create minute cavitation bubbles that force contaminates from objects placed in the tank. We use a biodegradable cleaner in conjunction with the ultrasonic cleaning tank. Nothing can clean a chain, derailleur or cassette better than ultrasound cleaning. It is through the use of ultrasonic cleaning that enables us to find small things such as cracked pulley wheels in the derailleurs.


A properly functioning rear derailleur is vital to our conversion. If the derailleur is worn or damaged then the bike will never shift correctly. Ultrasonic cleaning removes anything that might inhibit its proper operation. After cleaning, each pivot point of the derailleur is lubricated. If the jockey wheels are contaminated they are dissembled and cleaned. Sometime the jockey wheels are so worn they need to be replaced. The good new is they cost very little to replace. 




Evaluating Derailleurs for eBikes

Evaluating Derailleurs for eBikes

Evaluating Derailleurs for eBikes

Island City Bikes, Bafang installation

Please Note: When I refer to a "worn out" derailleur I do not mean an abused derailleur. All bikes that have been cared for and ridden for years at some point will have a worn out derailleur. A worn out derailleur means that the bike has been used as it was intended when initially purchased.


Ninety per cent of all derailleurs we see, function as designed after cleaning and lubricating. Some derailleurs are of such quality they should be restored, rather than replaced. Restoration means new pulley wheels, barrel adjusters, and cable clamp. These items are not very expensive and it is a shame to toss out a good derailleur because of a $20 part.


Note: Some of the finest derailleurs we see are Sram. Even their low end derailleurs are very well made and are worth restoring. While racing I always used Shimano groupsets and paid little attention to Sram groupsets. Now, because we work with derailleurs every day, I have to concede...Sram makes fantastic derailleurs. 

Shift and Brake Cables

Evaluating Derailleurs for eBikes

Evaluating Derailleurs for eBikes

Bafang Installation

Shift cables and shift cable housing are integral to the shifting of your bike. Brake cables and brake cable housing are essential to stopping your bike. It is our job to insure every bike we convert to electric has sufficient braking capabilities and can shift between gears smoothly. In order to do this the bike has to have good cables with clean cable housing. We have seen many bikes where the cables have been replaced but never the cable housing. Using new cables in old housing may not solve shifting problems. We inspect each cable and cable housing alike to determine if it needs replacement. First, we replace any old cable housing with new cable housing. There have been a number of improvements to cable housing over the years, such as plastic liners, and the cost for new housing is minimal. We also look for poor routing, rust, or and kinks in the housing. It matters little how new a cable is if it is being run through housing that is not up to the task. 


The Chain

The Chainline

The Chainline

image22

This is our Park Tool Chain Checker. After cleaning the chain we check it for wear. For 7-10 speed chains .75% elongation means chain needs to be replaced. For 11-12 speed chains the limit is .05%. If a chained is not replaced it may fail under the power of an electric motor. 

How a chain ages is the bushings (and pins) of the chain get smaller as they continually roll over the chainring and the cassette. This not only make the chain longer (chains do not really stretch) but makes the chain move forward and aft effecting shifting and causing premature wear of the cassette and the chainring. At some point the chain will break. 

It is a myth that eBike motors snap chains. Ebike motors snap old worn chains, but new chains are perfectly up to the the task of handling a mid drive motor. 

The Chainline

The Chainline

The Chainline

Island City Bikes Bafang installation

Chainline is the most difficult aspect of any eBike conversion. Chains are most efficient if running in a straight line but this is not possible with multi geared bikes. Typically, the only straight line between the cassette and the chainring is the cog in the middle of the cassette. Other than that one straight line, the chain deviates up into the low gear and down into the high gear. Under human power this system works. However, the power of an electric motor will exploit any deviation of the chainline and can cause the chain to fall off (chain drop). It is the task of the builder to find the most efficient chainline. We do this through the use of a variety of spacers that are balanced between the motor axle and the chainring interface. It is not easy, and takes patience. However, dropped chains, that are the result of poor craftsmanship, is inexcusable. 

The Chainring

The Chainline

Lekkie Chainrings

Island City Bikes Bafang Insallation

This is a stock chainring for the Bafang BBS02 750 watt motor. It is made of stamped steel, comes with a plastic cover and has a very limited offset. Because if its limited offset it is, at times, inadequate for establishing a good chainline. Sometimes it works perfect and other times it will not work at all. The Bafang stock chainring for the 750 watt motor comes in three sizes, 44T, 46T and 48T, and all three have the same offset. The offset of a chainring is what moves the chain closer to the bike frame. If any bike requires more offset than a stock Bafang chainring supplies then a Lekkie chainring must be used. 


Again, it is pointless to build or convert a bike to electric knowing the chain will fall off on the first ride. The proper chainring must always be used.

Lekkie Chainrings

Our Battery Company, UPP

Lekkie Chainrings

Island City Bikes Lekkie Chainring

This is a Lekkie 42T chainring. It has a 9mm offset that can put the chain right in the middle of the rear cassette. It is made of 7075 machined aluminum, lightweight, and most importantly it uses the narrow/wide tooth pattern. A narrow/wide chainring works so well at keeping the chain on a bike it has replaced the chain keeper. It works very well on any bike where chainline is an issue. Were it possible, we would include the Lekkie chainring on all of our builds as standard. 

Shift Sensor

Our Battery Company, UPP

Our Battery Company, UPP

Island City Bikes Shift Sensor

We install shift sensors on all of the bikes we build and all of the bikes we convert to electric.  All bikes over 500 watts need a method of interrupting the power between shifts. A shift sensor cuts the power of the motor while the gears are changing. This relieves the pressure on the drivetrain. Most electric bikes sold in bike stores are between 250 and 500 watts. At that level of power, a shift sensor is not necessary. Our motors are  750 watts with a peak wattage of 1,500 watts. These are very powerful motors and that is why they need a power interrupt while changing gears.

Our Battery Company, UPP

Our Battery Company, UPP

Our Battery Company, UPP

Island City Bikes Lithium ion eBike batteries

Nearly all lithium ion batteries and battery packs come from Asia. We purchase all our batteries from Unit Pak Power (UPP). As far as we know we are the only retailer in the US that discloses where and from whom they purchase their batteries. We believe the consumer has a right to know where their eBike battery was manufactured. Any Lithium Ion battery that is not made by a professional, well established company is assumed to be dangerous. Our battery company is one of the largest in the world and has consistently provided us with first rate batteries. Our battery failure rate is zero. Companies like UPP, spend hundreds of thousands of dollars in testing equipment to insure their batteries are safe and reliable. 

Battery placement

Battery placement continued

Battery placement continued

Island City Bikes Trek Bafang conversion

Our first choice for the placement of a battery is on the downtube. A downtube battery is designed to interface with the downtube of the bicycle in such a manner that easy installation and removal is made possible. 


What are the options if there is no room to place the battery on the downtube? There are some bikes where there is no room on the downtube due to size of the frame or the battery is impeded by the shock absorber of the full suspension bike. 


We stock all types of batteries in order to find the right battery for any bike. We have side load batteries, odd shaped batteries, even batteries that look like a water bottle. One way or another we will find the right battery for your bike.


Battery placement continued

Battery placement continued

Battery placement continued

Island City Bikes Trek full suspension Bafang build

The bike pictured above is an example of a bike that cannot accommodate a standard downtube battery. In this case, we chose a side load battery and mounted it on top of the toptube. We prefer a side load battery for mounting applications such as this, because they are lighter. We also have a very small, behind the saddle battery, that we use on some bikes where it is impractical to mount on the toptube.


Battery mounting is not only about the "where" but also the "how." We have developed certain methods that allow us to make a very strong connection between the battery baseplate and the frame of the bike. On occasion we may opt to add an additional Rivnut to the frame to insure a firm connection between battery and frame.  


Esthetics vs. Function

Battery placement continued

The Bafang Mid Drive Motor

image23

The picture above is from Arron Walter's "Hierarchy of user needs." The foundation of this pyramid and from there it ascends to esthetics. This is the model we use with all of our conversions. Function always has priority and when that is established everything else will follow. Does that mean esthetics is not important? Quite the opposite. I have never met any bike owner who was not concerned with how the bike looked. In addition, we care about every bike we finish is a beautiful bike. That is why we spend so much time getting our cabling perfect for each bike. We polish the spokes, clean every mark from the frame, remove every speck of grease from the drive train, remove any rust, replace missing nuts and bolts, and prime bare metal. We do it because we are proud of our finished work and it would not make sense to do it any other way.



The Bafang Mid Drive Motor

The Bafang Mid Drive Motor

The Bafang Mid Drive Motor

Island City Bikes Bagang BBSHD

What motor will we install on your bike? We use the Bafang mid motor exclusively. The name Bafang may not be a familiar name here in the US but it is throughout Europe, Asia, South America and pretty much everywhere else. It is the most popular motor in the world selling over 1,000,000 units a year. This motor is chosen over other brands due to its reliability, availability of parts, lightweight, no maintenance required, allows end users to set their own speed, and is the most powerful mid drive motor on the market. 


All other electric bike motors combined sales do not add up to a fraction of the number Bafang sells each year. We purchase Bafang motors 200 units at a time and by purchasing in quantity it allows us to keep the price of our electric bikes and electric bike conversions to the lowest possible. We have built hundreds of electric bikes with this motor and there is nothing we do not know of its engineering quality. We will always choose this motor for our clients as it is...to quote Tina Turner, "Simply the best." 

Cables, Cables, Cables....

The Bafang Mid Drive Motor

Cables, Cables, Cables....

Island City Bikes eBike cable management

A man called me last year and said, "Dr. Carpenter, your cabling looks like crap." I said, "I know it does and that is why I lose sleep every night trying to figure our a better way to route cable." 


There are three crisis moments in building electric bikes...battery placement, chainline, and cabling. After the battery and motor are installed comes the attaching of the display, display control, throttle, electric brake cut off brake levers, green button, main harness, motor cable, shift sensor, speed sensor and power to motor cable. That is a lot of cables. 


What makes cabling so difficult is every bike is different is size, make, model and year of manufacture. Folding bike, full suspension bikes, extra small frames, extra large framesets, cargo bikes and tandem bikes all require different techniques. The only way to become adapt at cable management and cable looms is to do a lot of them. We work with cables 7 days a week, we learn from one another and we critique the work of one anther. Because there is such a wide variety of types of bikes it is impossible to be able to teach a single method of cable management applicable to all bikes. 


Today I was watching a young woman in our Alameda shop route cables and she said "What should I do?" I said, "Do it in a manner that you think meets the goal of esthetics and function." She is a licensed beautician...I watched her slowly begin to braid the cables as if they were hair. I had never seen anyone braid the cables of an electric bike. This is the type of creativity that is valued by all companies, big or small.

Waterproofing

The Bafang Mid Drive Motor

Cables, Cables, Cables....

Island City Bikes waterproof connections

This is a picture a the cable coming from the battery to the motor. The connection is an Anderson Powerpole connector with a locking pin. We then use heat shrink to seal this connection. The other connectors on the bike are Higo connectors. Higo connectors are waterproof connectors that are used in a marine environment. All of the connectors on any bike we build or convert to electric will have Higo connectors. However, we will heat shrink each Higo connector to double insure your bike will be as water resistant as possible.


We are always ask by those who are commuting on their bikes, "How waterproof are your bikes?" I think the best answer to that question is what happened to one my clients who had her folding bike converted into an electric bike so she could commute to work. The very next day after I delivered her bike to her home I received a frantic call.


I was in my office when the call came in and she said..."I am on a bus crossing the San Francisco Bay Bridge and my bike is on a rack on the front of the bus and it is pouring rain...will my bike be ok?" I said..."Do not worry, we will take care of you if anything happens but I am sure the bike will be fine." I hung up and thought: The bike I built is going 60MPH on the front of the bus in the pouring rain....ye gads. Twenty minutes she called back and said..."every thing is fine and the bike runs great." Yes, all the extra work we spend using heat shrink on all our connections paid off and we do have the most water resistant bike on the market.


Securing the motor

Electric Bike Specific Tires

Tires...Often Overlooked

Island City Bikes installing a motor stabilizer for bafang motor

This is a picture of one our technicians preparing a bike for a motor brace. The use of a motor brace is one of a number of ways we use to secure the motor to the frame of the bike. The standard method that has been used by many (all) builders is to crush a fixing plate into the bottom bracket shell. We do not like that method so we devised our own. Our goal in designing a method of securing a motor to the frame is that it had to be robust enough that we could provide a lifetime guarantee that it will not come loose. The end result is that once in place, your motor will stay in place for the lifetime of the bike. 


Tires...Often Overlooked

Electric Bike Specific Tires

Tires...Often Overlooked

Island City Bikes building electric bikes, evaluating tires

During the cleaning and inspection phase, we found this split in the tire. We called the owner, showed him the picture and said the tires need to be replaced as they pose an immediate danger to any rider of this bike once we have converted it to an electric. He agreed.


What do I do when an owner refuses to replace a damaged tire such as this? I replace it anyway. I pay for it out of pocket. Why do I do this? First, I think you would do the same. Second, I would never wish to contribute to the injury of another in the name of profit. In this business, if I cannot afford give away a tire, cable, tube, housing, or anything else to make a bike safe, then it is time to retire. 


I suppose when I am no longer in charge  things will change. For now, I own the company, and I do whatever it takes to insure every bike we build or convert to electric meets the highest standard of safety.


Electric Bike Specific Tires

Electric Bike Specific Tires

Electric Bike Specific Tires

Island City Bikes and eBike specific tiries

PLEASE READ

On all bikes we convert to electric we talk to the owner about tires. Tires are the most important part of any bicycle. Tires are the only part of a bike that comes into contact with the road. The only part of the tire actually touching the road is called the contact patch. On a narrow tire the contact patch is very small which means the bike will go into a skid much sooner that a tire with a large contact patch. On an electric bike you want to have the widest tires possible, within reason, because that increases the contact patch that interfaces with the surface allowing much better braking control. Also, large tires will roll over obstacles, cracks, bumps, and potholes much easier than narrower tires. 


A second consideration is the thickness of the sidewall. On stock tires the sidewalls are notoriously thin. Thin sidewalls make a tire much lighter. On electric powered bikes weight of tires is not an issue so eBike rated tires triple the strength of the sidewall. Strong sidewalls are very important to any electric bike. I cannot say this with greater emphasis. When descending and cornering at high speed on a eBike it is essential the sidewalls of the tires are robust enough to keep them from rolling off the rims.


A third consideration is puncture protection. EBike rated tires are loaded with puncture protection material that would not be possible on a standard tire due to its added weight. Weight of the tire means nothing to a bike that has a powerful motor such as the Bafang. All electric bikes should have electric bike rated tires. Or, well constructed tires with lots of tread remaining.

Special Builds

Xtracycle Bafang Conversion

Electric Bike Specific Tires

Island City Bikes Tandem build with Bafang BBS02 750 watt

We do a lot of special eBike conversions such as this tandem bike. We carry every part necessary for every build in stock. It is a cardinal rule that once a bike is placed on a workstand it will stay there until the build is complete. That means the technician must have every part he or she needs to complete the conversion.


I will always remember the time a tech was building a bike and called out to me for a special part and after searching for the part I said, "Sorry, I forgot to include more of those in my last order." He glared at me...then slowly, without a word, took the bike off the stand and rolled it into a corner and then folded his arms. I never let that happen a second time. That tech is a professional and views himself as a professional and as a minimum deserves every tool and every part needed in order to do his job. 

Tern Folding Bike

Xtracycle Bafang Conversion

Xtracycle Bafang Conversion

Island City Bikes, Tern foldong bike with Bafang BBS02 750 watt

This a beautiful example of a folding bike that we built using a side-load battery and a BBS02 750 watt motor.  A folding bikes is one of the most difficult bikes to convert to electric. Battery placement is always an issue as it has to find a place on the bike that can allow a rigid installation. Motor placement is difficult as sometimes the shape of the frame will not allow a motor brace. Lastly, cabling is always a challenge because all cables must be routed on the bike in such manner that it will allow the bike to fold. Fortunately, we manufacture our own motor braces, stock all necessary extensions, and have an assortment of batteries to choose from. This week we converted three Giant Expressway folding bikes and all of them came out as powerful folding bikes ready for commuting.

Xtracycle Bafang Conversion

Xtracycle Bafang Conversion

Xtracycle Bafang Conversion

Island City Bikes Xtracycle Bafang conversion

We convert more cargo bikes into electric bikes than any other company in the US. One of the reason people bring their cargo bikes to us is we do not charge any more for a cargo bike conversion than we would for any other bike. 


We have special equipment for working on cargo bikes so their size and weight are not a problem. We use a special pneumatic bike lift, manufactured in Eugene Oregon, that allows us to lift the bike and rotate in any direction in order to inspect, calibrate, and repair. Also, we keep in stock all the extension cables, displays, and XL chains necessary for these conversions. We also have eBike rated tires in sizes that fit all cargo bikes. Cargo bikes are one of our favorite bikes to convert.

In conclusion

Thanks for reading about our conversion of standard bikes to electric bikes

Of course, there is far more involved in converting your bike into an electric bike but I think this can give you a general idea. I hope you do not think I am boastful in some of the claims I make but as my Mother used to say, "It isn't bragging if it's true." A man called me today and said, "What eBike at the bike shop do you recommend I buy?" I said to him, "In all honesty, none." "The best electric bikes available anywhere are sitting here in the room where I am standing." In our shop I am surrounded by the bikes of our clients that are being converted into electric bikes. There are cargo bikes, mountain bikes, tandem bikes, and city bikes. All of which, I believe are the best electric bikes to be found anywhere. 

Alvin Carpenter, PhD

Alvin Carpenter, PhD