DIY Electric Bike Conversion

Here is how I used electric bike kits  to convert bicycles into e bikes. Only one e bike conversion is shown here.  

The bikes were older daily rides that needed work and new paint, so this was a chance to fix them up and install the kits all at once. 

Before you get started with a conversion, decide what you want to use as a donor bike, what kind of riding you want to do, the kit you want, and finally the cost. You may be tempted to just get the cheapest kit out there, which might work, but it is best to try and figure out what you want the final conversion to do. 

If you need help in deciding the size of motor and battery pack to use, cruise on over to: http://www.evsroll.com/Electric_Motor_for_Bike.html for details on how much power you need. It is interesting if nothing else. 

Step 1: The E Bike Kit

Here is the kit used in the conversions. You have a rear wheel motor, controller, thumb operated throttle, on/off switch, brake levers with kill switches (not used), and battery to control cable. 

The motor in this kit is a 500 watt continuous, 1200 watt peak power geared motor especially suited for hills. This motor requires a 22 Amp continuous controller. 

 The brake levers had kill switches on them. Since the throttle is thumb operated, the kill switches and extra wires did not seem necessary. This proved true later on. If you need to stop, you just let go of the thumb throttle, and the motor stops. It is intuitive.

The kits also came with nylon battery bags. These bags are well made, but the battery instructions warn against using these bags! Go figure. 

Cost of Kit: $350
Controller:  $  50 extra 
Total cost for the conversion including the kit, battery, and parts was about $950

Comments

[Zaphod Beetlebrox]

I just saw this http://www.boostedboards.com/ 
I also saw an article about using the same ( or similar) brushles motors and a lion batterpack do do the same thing for about a $100 bucks, with out board.

I am wondering about using the same components on a bmx bike. Does anybody know if this would work.  Could I wire a potentiometer directly between the batter and motor, instead of a motor controller?

[tomgriffin42]

I'm just now wondering about an ebike, and was impressed by your project. A couple of questions, though. 1) Why did you select a rear-wheel drive instead of front-wheel? The front-wheel drive looks easier to install. 2) How did the price jump from $350 for the kit to almost $1000? Are batteries really that expensive? Are there no alternative battery systems? Nice job, though.

[oldskoolhead]

i think everyone should have an ebike, i bought mine, but intend converting one myself at some point, i use mine to travel to work, costs 5 pence a day in electric and batteries being lead acid need replacing approx every 6 months costing 140 a year so it costs me approx £2.94 approx a week to get to and from work including battery expenses and charging (though i charge my batteries at work as well) my works is approx 5 1/2 miles away and in a taxi would cost £8.00 e/w the bike cost me £450 so based on the taxi expense the bike paid for itself in under 7 weeks and i normally would only have the option of a taxi on 1 leg of the journey as i work late and the busses arnt much cheaper anyway lol, the bike i have is a bit embarassing to ride lol but the people who might laugh are either walking or spending more on a single bus journey than i do a week or paying more in road tax than i do on the whole thing so secretly im laughing at them lol......ebikes rule

[EVsRoll]

Wow, that's great. Thanks for providing your costs...very interesting. Here in the good old USA most people still commute by private car...talk about expensive!
You can't beat a ebike most of the time at least...eBikes Rock!

[yellowcatt]

Thanks for this instructable, I am seriously thinking about converting a bike this year.

Anyone have advice on what type of battery would be best for me to use?

My bike will have an unusual usage pattern because I spend a lot of time out of the country. It would be used regularly for some of the time and then left unused for two or three months at a time when I am working abroad.

[cnebikes]

hi, sir.
The best type of battery is up to your motor choosing and your bike. Usually, people like to use rear rack lithium battery if you use 48v hub motor. And there is new bottle lithium battery to choose if you like to use 36v hub motor. The rear rack battery can be installed with all bikes. And the botte battery is good fo 26" and 28" male bike. So if you can give me one photo of your bike, that will be a better and exact advice.
Any questions, you can come to cnebikes.

Jason

[pteranosaur]

Allowing for curing,my past experience painting with rattle cans went very well.The paint I used cured into a very durable finish,MTB use and all !!

[EVsRoll]

Right on! Good comment, I noticed that the paint did scratch way more easily when it was newly applied, and seems to be getting harder over time...

[yellowcatt]

I remember a few years ago a friend made an 'oven' for baking the frame of a motorcycle he had repainted. It was a large box made out of sheets of OSB with a couple of 500w halogen floodlights inside.
It seemed to work quite well.

[pteranosaur]

Itching to get my hands on 'Chameleon' paint from Dupli-Color.Wanna purple/green recumbent !

[kmalivuk]

The best way I've found to bend a *steel* frame is:
http://www.sheldonbrown.com/frame-spacing.html
Thanks for the article. I'm a bicycle mechanic and realize it's time for an e-bike in my commuter bike stable.

[audioredneck]

A couple of other things you can do to help when painting is to take a hair drier and warm the surface up to body temp before painting and using a few shop lights to "bake" it afterwards. A few light layers of clear also helps. Then hitting it with a buffer and some wax (use a cleaner wax if the the clear is dull, otherwise pure carnuba). If you use cleaner wax or polish, you want the buffer to stay damp.

All in all, cool build!

[EVsRoll]

Thanks for the tips. I need to to some touch up by now. I can tell you that these ebikes are the best little rigs I ever had.

EVsRock!

[Ben Mighall]

Hey, how much does this cost and can you still pedal the bike after the "surgery"?

[EVsRoll]

Hi Ben:

The complete bike costs around $900-$1,000. This may but seem expensive until you consider that this (and the wife's too) ebike takes me all over the place. It can replace a car for many in town errands. I love the ebike and recommend one to everyone.

Yes, you can pedal in fact much of the time. I have written some pages on the subject since finishing the bike. I explain the pedal assist bike in some detail.

If you are really interested, check here: http://www.evsroll.com/Electric_Assisted_Bicycle.html

EVsRock!

[markswagan]

Wattage: 251 - 350w Voltage: 36V Power Supply: Lithium Battery
Wheel Size: Other Motor: Brushless Certification: CE
Frame Material: Aluminum Alloy Foldable: Yes Max Speed: 30-50km/h
Range per Power: > 60 km
Packaging & Delivery
Packaging Detail: CTNS
Delivery Detail ONE WEEK
Specifications
electric bicycle conversion kit
12-28''wheel
350-1000w
CCC, CE, ROHS, ISO9001, EN15194
Let's make things better!
electric bicycle conversion kit
FOR EURPEAN MARKET
BATTERY MOTOR WHEEL WEIGHT
24v-10AH LIMN FRONT gear motor 100MM 150w-250w 12"-28"700C 13KG
24v-10AH LIMN FRONT gear motor (100MMwith DISK BREAK ADAPTER) 150w-250w 12"-28"700C 13KG
24v-10AH LIMN REAR gear motor 135mm+6 CLUSER 150w-250w 12"-28"700C 13KG
24v-10AH LIMN REAR gear motor (135mm+6 CLUSER with DISK BREAK ADAPTER) 150w-250w 12"-28"700C 13KG
36v-10AH LIMN FRONT gear motor 100MM 150w-350w 12"-28"700C 16KG
36v-10AH LIMN FRONT gear motor (100MMwith DISK BREAK ADAPTER) 150w-350w 12"-28"700C 16KG
36v-10AH LIMN REAR gear motor 135mm+6 CLUSER 150w-350w 12"-28"700C 16KG
36v-10AH LIMN REAR gear motor (135mm+6 CLUSER with DISK BREAK ADAPTER) 150w-350w 12"-28"700C 16KG
FOR USA MARKET
BATTERY MOTOR WHEEL
24v-10AH LIMN FRONT direct motor 100MM 200-350w 12"-28"700C 15KG
24v-10AH LIMN FRONT direct motor (100MMwith DISK BREAK ADAPTER) 200-350w 12"-28"700C 15KG
24v-10AH LIMN REAR direct motor 135mm+6 CLUSER 200-350w 12"-28"700C 15KG
24v-10AH LIMN REAR direct motor (135mm+6 CLUSER with DISK BREAK ADAPTER) 200-350w 12"-28"700C 15KG
36v-10AH LIMN FRONT direct motor 100MM 250w-500w 12"-28"700C 18KG
36v-10AH LIMN FRONT direct motor (100MMwith DISK BREAK ADAPTER) 250w-500w 12"-28"700C 18KG
36v-10AH LIMN REAR direct motor 135mm+6 CLUSER 250w-500w 12"-28"700C 18KG
36v-10AH LIMN REAR direct motor (135mm+6 CLUSER with DISK BREAK ADAPTER) 250w-500w 12"-28"700C 18KG
LEAD ACID SYSTEM
24v-10AH system OTHER PARTS SAME CHOICE AI LI SYSTEM


Http://www.electricbicycle-conversionkit.com

[pedalmonkey]

Hey, nice 'ible. Quick question(s): What's the wheel diameter and spoke count? I have an Xtracycle that I built a bout a year ago and want to electrify it, but I must make sure that the hub motor/wheel assy will bear the intended weight. Right now I have a 26"/40 spoke tandem wheel. I would also like to know what the final (required?) distance is between your dropouts. Thanks, j

[gcruik]

I put together a cruiser, a "free radical," (name of the Xtracycle extension), and an e-bike kit. about 5 months ago. Put it on the rear. Works fine. I used their standard 26' kit. It now comes with the capability to use disc brakes. Have about 700 miles on it. No problems. I can haul a lot of stuff, and have done so. Suggest full scale xtracycle kickstand.

[EVsRoll]

Thx for the kickstand tip! I am finding out just how heavy these bikes can be when parking them. I'm up to about 250 miles and am totally sold on e bikes. There are soooo many advantages you would not even think of like being able to hit the throttle just in time to scoot of the way of an aggressive or inattentive driver. EVsRock!

[EVsRoll]

The wheel with the motor is 26" with a killer deep V alloy rim, and 32, 10 gauge spokes laced 1 cross! That gives you an idea of the strength, it is built almost like a small scooter. Distance from inside dropout to dropout is about 5.7 inches after shimming. The added shims are about 0.4" thick all together. As for required...I found that I needed two shims for sure on the cluster side to keep away from the seat stays. Maybe there is another way, but that worked for me. Opposite the cluster, I needed an additional 0.25" just to center the wheel. The thing is that the motor axles are keyed (flat on 2 sides) to fit tightly in the dropouts to help prevent axle spin from motor torque. This means very little side to side wiggle in centering the wheel like on most bikes.

[pedalmonkey]

Groovey. $950 is still a little steep for me right now...however, I was at a small appliance repair shop last week and asked the owner if he ever came across any used DC motors. He gave me two on the spot. Both work and look to be sufficiently beefy for my project, though I will need to buy/scrounge controllers, batteries, etc., for the build. Fortunately, my brother-in-law is a large-scale rep for a major high-end tool manufacturer and will supply me with batteries and chargers for very little money. I just have to find the rest of the components. Gearing and mounting are relatively easy for me as I have a background in (and several spare parts and materials from) aircraft maintenance. The controller looks to be the most expensive thing. Are there any schematics available to home build a controller? I promise to document the build but I'm going to need all the advice and assistance from more educated/experienced individuals that I can find.

[EVsRoll]

PedalMonkey: Here may be what you are looking for: http://endless-sphere.com/forums/viewtopic.php?f=2&t=14798 Custom boards for the DIY controller..........

[pedalmonkey]

Hey, thanks. I haven't even messed with the motors yet-other projects are underway at present which are even more important. ( mainly the ones my wife sez I have to complete. )

[EVsRoll]

Hey Pedal Monkey: Sounds like you have quite the project going. Although I have seen plans for Controllers, I can not remember where....sorry amigo. I would probably shop ebay, they have quite a range on there right now, mostly $25-$50. If I remember right, there was also a guy who used the controller off of a forklift. Another option might be a golf cart since I think a lot of them use a 36 volt set up...lead acid though. Anyway, keep us posted!

[ailgup]

ebikes are okay but they -cost more (900 vs 150) -are less green than (battery disposal, something has to make the electricity probably coal vs. 100+mpg) -travel less distance (can only go a limited number of miles) -are slower (few can go faster than 30mph) -and weigh a heck of alot more than motorized bikes while the noise and need not to register the bike (in some states) are pluses i would not say that is $750 better and then in a few years when the battery goes even more money. I am not trying to start an argument but just show people that bikes can be alternatively powered other ways which for them may or may not be better. I have even seen some people combine the two into a super emotorized bike which used the electric motor on starts then moves over to the motor.

[EVsRoll]

Sir or Madam: Thanks for the comments. However it is difficult to follow your argument given the broken English. I will try to reply as much as possible. The E Bikes featured top out at about 20 mph not pedaling, and 25-30 mph with pedal assist. You may notice that the motors on these bikes are not however built for speed, but climbing and pulling ability. Even if I wanted to exceed 20 mph, it is not legal to do so. The motor is regulated at 750 watts, and speed on an e bike to 20 mph. These are still Bicycles, mountain bikes at that. They are NOT designed to travel at road speeds for any appreciable distance except downhill once and awhile. If you have ever crashed a bike at over 20 mph you know they tend to break up real fast. I have had 1100 cc motorcycles that could travel over 100 mph easily, but they were designed to do that. The e bike is probably one of the most efficient machines on the planet today, so the argument I think you are making about coal power does not wash at all. One gallon of gasoline has the energy equivalent of about 36 kWh. These e bikes have the energy equivalent of about 1/2 kWh. An average car or truck can travel say 20 miles on that one gallon. The e bike battery can then be recharged 72 times for the same amount of energy as a car or truck. Each battery charge is good for 20 miles or more. So, you are getting 72 times as many miles from the e bike as the car or truck. This is just theory, real life is different. Since I pedal as I ride and only use the power when needed, I actually get more than 72 times the car or truck. Note also that my e bike can (and will soon be) charged from a wind turbine or solar panel array. We have lived off grid using solar before, it is entirely possible. Coal fired power is the main utility today, but it is not the only energy source by far. See my site for more information regarding energy sources: http://www.evsroll.com. As far as the distance argument, it is mostly a bluff. For example, I routinely travel the 3-5 miles to a number of stores top get parts for things like e bikes and other DIY projects. I only need my bike to do this, the e bike is great especially to help cut time and haul stuff. I get to the store as fast or faster than people around me with minor exception. Even if I am 5 minutes slower, so what, big deal, what am I missing, 5 minutes of TV? On an e bike I am out of doors which in the good weather is a pleasure. I do not want to be cramped up in a car in traffic anyway. Look around you at people in their rigs sometimes, are they happy looking at the stop light? They don't look like it to me most of the time. It is a fact that most people drive their cars and trucks on short, local trips. My e bike does this just fine. I almost always have battery power left over as a matter of fact. If I need to venture further, then I drive my 1/2 ton pickup truck, but I do that a lot less these days, and hope the trend continues. Take a look sometime at the average cost of vehicle ownership. It is many thousands of dollars every year, up to about $8,000 for a lot of people, especially with a new vehicle. If these bikes last one year, they have paid for themselves up to 4 times over from that point of view. As for the motorized hybrid bike you propose, not for me. One of the coolest things about and EV is the quiet but powerful whir of that electric motor delivering pure torque to the driving wheel or wheels. I do not want to hear any clattering pony motor thank you, burn my leg on the exhaust, or mix oil and gas for some little snarling 2 stroke. I'll save that for my Husky chain saw. By the way, I doubt if these e bikes weigh much if any more than a gas powered bike.

[ailgup]

I do agree with most of the points you make nearer to the end of the comment and yes it is a bike not a car. I guess that you can have a different view about what you want to do with it. For some it can serve as an assistance to pedaling while others want do go much longer distances use it as a sort of moped. I am not trying to argue with you because I still believe that ebikes are awesome and am partially jealous because I don't currently have the funds to purchase one. The point of my comment was merely to show some people who were looking into powering a bike that there is more than one way to do it and let them make a decision based on what their needs/desires are.

[ac1D]

Ebike system is both heavy and expensive. You can achieve a better result for cheaper, using your own part.

[EVsRoll]

I somewhat agree. You can build your own, only it will probably be heavier if you desire much of a range. It is a fact that Li-Ion batteries only weigh about 1/3 as much as lead acid batteries. If you go cheap, you are going to go lead acid. Also, lead acid only gets about 1/3 the number of charge cycles as Li-Ion. This means that you will be replacing them 3 times as often. Since they cost 1/3 as much as L-Ion, you save nothing on batteries. I had this experience with my electric car conversion (http://www.evsroll.com/Convert_your_car_to_electric.html) in 2002. The lead acid is cheaper upfront, but you need a lot of them, they are heavy, and the replacement cost adds up. As for the motor kit, the kit installed on this instructable is pretty much state of the art. You get what you pay for. As the Tappet Brothers (NPR Saturday AM) say "It is the cheap man that pays the most." While not always true, in this case it applies.

[ac1D]

I agree and understand what you mean, but is not lithium-ion battery really sensitive? Would it really be a nice idea to install these on an electric bike? They will lose their ability to hold their charge even when you are not using them, and depending on your charger, they(even if claimed 2000+) will only hold 750-1000 charges. If you are really going to put money on a battery, should not you go with an Phylion battery? They are almost the same price as li-ion battery. What I am saying may be rubbish, I have no experience in electric bike conversion. But I just want to try to understand everything before I decide if I want to try and achieve this project.

[EVsRoll]

Good point: Yes they (Li-Ion) are VERY sensitive. A couple of things to watch out for: 1. Get a good BMS - battery management system - board with the batts. 2. Get a good charger. 3. Condition the batts when new - I found this out the hard way. The entire pack will only give as much power output as the lowest cell in the pack. It is important to condition your pack to prevent this...let me know if you need more info on this... 4. Li-Ion packs do hold a charge pretty well as compared to Ni-MH...at least mine have not lost much charge just sitting there (LiFePO4) 5. Make SURE that your controller has a low current cut-off. Mine are at 31.5 volts. If you pull the pack below the cutoff voltage, it WILL damage the pack. This is one thing that these batts do not like. When you purchase your pack, I recommend you pay attention to the manufacturers recommendations. 6. I do not know much about the Phylion battery - it sounds like some Li-Ion variant? I went with the LiFePO4 since they do have many advantages over other packs, and some car manufacturers are using this chemistry now days along with Li-Mn (Nissan) and other Lithium packs.

[jimenezlee]

if available, an air compressor will remove them even faster and easier. Plug the opposite end of handlebar grip with palm of your hand. Then pump air into the grip you are trying to remove. The air will unstick the grip and push it out. This is how bike shops do it.

[EVsRoll]

Thanks for the tip.

[jimenezlee]

Thanks for posting this article, makes me want to go out and convert mine! If I could only find a spare 1k... :)

[EVsRoll]

Yeah, the cost is most definitely a big factor. We decided to try this instead of another car. So far, we have only started our pickup once in 3 weeks thanks to the e bikes. Hey, you might try an SLA kit, they are out there for about 65% or so of the cost of the L-Ion kits. Check Crystalyte: http://www.eco-wheelz.com/catalog/crystalyte-roadrunner-408-kit-p-154.php - the SLA batts run about $50 each or so and the shipping varies of course.

[jimenezlee]

these wires should be protected against cutting on the metal box. Electricians do this at a wire installation to the junction box. So a round hole to fit a plastic plug used in home junction box installations, sold at any hardware store may be better than this slot to protect the cable's insulation against cuts from rubbing the metal, specially because of all the vibration.

[EVsRoll]

Hi: Good point. I neglected to show how I protected the wires. First I insulated the slots with Epoxy coating. Then I just took a piece of tubing, slit it , stuffed the 3 wires in, wrapped a bit of electrical tape around it, and fit it into the box. This works great to seal, protect, and is easy to remove in case of a flat when you need to remove the wires! The photo shows the wires in the tubing.

[pteranosaur]

To remove grips-slip a thin or pointed tool between the grip and bar,pour in a little water,and twist. Not good enuff? Do again,go deeper,add some water in opening,and twist grip...

[Dream Dragon]

I just want to make the point that different parts of the world have different rules for "Electric Bikes". If you buy a "kit" make sure it adheres to all local laws and guidelines, and follow the instructions that come with it to the letter. Modifying the kit in any way (like leaving out the kill switches), may make your vehicle illegal in some areas.

[EVsRoll]

Thank you for the information. In this area the concern seems to be that the power of the motor does not exceed 750 watts, and that you do not exceed 20 mph under battery power alone. As far as instructions, I should have mentioned that our kits came with NONE. Luckily I had built up an electric car before and knew which general direction to head. As for riding an e bike, it is very similar to riding a scooter or motorcycle and uses the same logic. Power on with throttle spring, power off with spring released. Motorcycles do not come with brake engine cut off switches. However, it safety regulations in your area require brake cut off switches, by all means use them.

[frollard]

Seconded - in a real vehicle, when posed with a dire last second emergent road condition, I slammed my feet on the 'brakes" -- turns out I had one foot on the brake and one on the gas. Regardless I crashed...(years ago). Grabbing at a brake when you're surprised by something -- "intuitive" doesnt cut it for white-knuckle situations where your hands seize up.

[EVsRoll]

Wow, sorry about the crash. I have been hit by cars before, and it is a bad day. Regarding the brakes, Sorry to lead people in the unsafe zone. The thumb throttles on our little rigs snap back the second you change position since they are under the gears and you need to make an effort to hold the throttle open. I must be getting old because my brake response with this setup is no faster than letting go of the thumb lever...in fact I think is slower to manipulate my hand over the brakes while still holding onto the throttle...you can not easily do both at once. It is either throttle, or brakes. Anyway, that is the reason for the comment. Sorry again to cause any safety errors...ride safe and ride far...just ride!

[frollard]

Agreed -- it seems it might be physically designed that you cant do both, but how about the other brake handle? :)

[EVsRoll]

Right...you could use the (left) front brake cutoff (assuming you are RH) as a backup if you think you need it. Remember too that the front brake is 70% of braking power, so don't just grab the front, or it's header time!

[EVsRoll]

Wow, sorry about the crash. I have been hit by cars before, and it is a bad day. Regarding the brakes, Sorry to lead people in the unsafe zone. The thumb throttles on our little rigs snap back the second you change position since they are under the gears and you need to make an effort to hold the throttle open. As with the reply above, these throttles are operate along the lines of a motorcycle or scooter, the logic is exactly the same. I have the experience of riding motorcycles coast to coast and points in between, so intuitive means "like a motorcycle." If the rider feels challenged, I recommend a highway patrol sponsored motorcycle safety course. They will teach you how to let go of the throttle. In any case, Safety First, and ride, ride, ride, whatever. The main point here is to get out and ride!

[jkoznek]

Cool but unfortunately ebikes are heavy... really heavy, so if you live upstairs or have stuff to lug around be mindful that these kits add 60 - 80lb to your bike. Keep that in mind when your battery dies. When that happens ebike just turns into a bike with a lot of weight and you have to pedal. I had an ebike for a little while and it turned out to be more hassle than just a regular bike.

[EVsRoll]

Yes, the conversion is heavy at 60 lbs as you say. However, in my experience, the power of the motor more than compensates. Yesterday when the battery cut out, I just pedaled home. I just weighed my old Schwinn Cruiser 7-speed which I converted to a 15 speed. It weighs in at 40 pounds! It by the way is no fun to lug around either. The e bike allows us to pull a 65 pound dog in a trailer at 20 mph plus on the flats, and 12-15 mph up 6% hills however. I would agree that lugging the e bike up stairs would be no fun. You might try one of the following makes if weight is an issue: Powabyke Lynx 40 lbs claimed Powabyke Puma 40 lbs claimed Urban Mover All models under 50 lbs claimed Whisper 806fe 42 pounds claimed Bionix Montague Folding MTB 43 pounds claimed Finally, the weight champion so far: Karbon Kinetics Go Cycle at 28.4 pounds! I bet it cost a few pounds too however. Anyway, there are lighter e bikes out there if you need one. Happy Cycling no matter how you go!