50+ Mph E-Bike

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Introduction: 50+ Mph E-Bike

About: Hi! I'm Luke and I run a small business building vehicle conversions, hand-making furniture, and doing out-of-the-ordinary projects. I have a formal background in mechanical engineering but also enjoy just w...

Hi! My name is Luke and I built a really fast electric bicycle that I also use as a replacement for my car! Don't worry if you don't know much about bikes or electronics...I don't either. I'll do my best to make this Instructable readable for everyone that's interested.

What is an E-bike, you ask? It's a regular pedal bicycle that has been converted to be driven by an electric motor. The motor can either supplement pedaling or drive the bike by itself (like an electric motorcycle that happens to have pedals). This will be discussed in more detail in the following steps.

Here are some quick stats on this project before we get into the details.

  • 50+ mph top speed
  • 8-speed transmission
  • Ludicrous acceleration
    • I don't have any numbers on this yet, but full throttle in a low gear will easily pick up the front wheel (i.e. it does wheelies)
    • I haven't found any local cars or motorcycles yet that can beat me in a 0-30mph drag race.
  • 45-55 mile cruising range
  • Battery fully charges in ~4 hours with a standard 120v wall outlet
  • Custom-built bike
    • Super light weight, around 55 lb (with motor, battery, etc)
    • 700c x 40c tubeless cyclocross tires
    • Rockshox air suspension
    • 180mm mechanical disc brakes
  • ~$2,200 material cost, broken down into:
    • $800 Battery
    • $550 Bike parts
    • $400 Motor
    • $300 Motor Accessories + Upgrades
    • $150 Misc Parts
    • Detailed parts list

Step 1: Motivation

So, why build an E-bike? Brace yourself, this is the boring section. Feel free to skip it and move on! If you're here for the long haul, here are the main reasons that I decided to pursue this project.

  1. Ease of commute
    • I have the pleasure of living in the beautiful town of Fort Collins, CO.
    • Almost every single street has a bike lane, and tons of people bike for pleasure as well as to commute.
    • Roads can get pretty crowded, and parking is always tough to find.
    • An E-bike presents "the best of both worlds"
      • I can commute anywhere within a fairly large radius around town, usually faster than a car.
      • I can park at bike racks (which are absolutely everywhere and in less demand than parking spots).
  2. Gas Savings
    • My only car is a big truck that gets 17mpg on a good day (and 13mpg on not-so-good days).
    • An electric bike is suitable for 95% of my transportation and is essentially free - I can charge it anywhere there's an outlet.
      • For the nerds out there, I get the energy equivalent of ~80mpg on the bike.
    • I carry large panniers (bags) on a rear rack so I can go grocery shopping, carry around big boxes, etc on my bike.
  3. No Tired Legs
    • I'm currently training for some elite 5 and 10k's (running races), so I'm running anywhere from 90 to 120 miles per week (13 - 17 miles per day).
    • Oh, you're a distance runner, don't you have plenty of energy?? Contrary to popular belief, us runners actually have less energy because we spend it all running!
    • So, sure I could just ride a normal bike around, but most of the time I'm just really tired out.
  4. Exploration
    • I love exploring, but there are some places you just can't get with a car, even a 4WD truck.
    • I've been living in my tiny house (see instructable here) for 8 months now, and it has a bike rack on the back.
    • With this bike, I can now drive my house way out into the moutains, desert, etc, then hop on the bike and explore to those really remote places!
  5. Fun
    • Nothing like zipping past other people while slowly pedaling backwards.
    • The acceleration is REALLY a lot. Like, drop you off the seat if you're not holding on tight.
  6. Sustainability / Environmental
    • As a mechanical engineer, this is a big topic for me.
    • Electricity is not necessarily 100% "free" or "clean", but riding around a light electric bike instead of driving a large truck is obviously an improvement in terms of energy use and emissions.

Step 2: Design and Options

Time to build a bike. Where to start? This step will outline the design process and some options I considered before finalizing a design. Then the next steps will go into detail about choosing parts and putting it all together.

What kind of bike?

Before you can convert a bike to an electric bike, you need the bike. The two main choices are mountain bike or road bike. Consider where you will be riding, the size of motor you're interested in, and how much pedaling you want to do. In general, mountain bikes are more stable due to wider wheels and heavier frames. Road bikes also generally don't have a suspension system, which means you'll feel every little bump. This goes from being slightly uncomfortable to painful and/or dangerous as you get up to faster speeds. So, I personally think the safer bet is a mountain bike, and you still have tons of options for getting exactly what you want out of the bike.

Buy, Modify, or Build?

For those on a tight budget, pulling the dusty old mountain bike out of your garage might be the best bet. Craigslist is also a great source for cheap used bikes of decent quality. For new bikes, sites like BikesDirect have some really good deals because they cut out the middle-man retailer. If you find something that's almost what you want, it may make sense to purchase that complete bike and swap out any components you want to upgrade (that's what I did). Finally, if you're feeling ambitious, you can always just collect all of the parts that make up a bike and assemble them all yourself.

Depending on the size and power of your motor, it's important to make sure that your bike of choice can handle the extra stress and weight of your conversion.

One last thing to mention is that building a bike up from parts is not necessarily less expensive. In fact, it's often more expensive. The tradeoff is that you get exactly what you want and don't pay for anything else.

Motor - Hub motor, mid-drive, or chainsaw?

Hub Motor

A hub motor is one that replaces either the front or rear wheel hub (the middle part) and occasionally both wheel hubs. They are generally the lowest cost option, most discrete, and lowest powered. They are commonly sold in power ratings of 250 to 1,000 Watts.

Mid-Drive Motor

Mid-drive motors go - you guessed it - roughly in the middle of the bike. They generally have an extra chain that drives the front crankset, which then drives the rear wheel. One of the coolest advantages of mid-drives is that they let you shift through your rear gears as you could on a normal pedal bike. This gives you a good range of speed and torque for everything from climbing steep dirt hills to cruising along your commute to work.

I've seen mid-drive motors in powers from 750 to 10,000 Watts. There is a practical limit to power here. At some point (I'd like to say it's around 3,000 W), the amount of torque and speed is just too dangerous for a bicycle. Additionally, bicycle components are usually not designed to handle super-human amounts of torque. At the very least, your components will wear faster than normal; at worst, components will break as you ride (think wheel getting bent out of shape, chain snapping, chainring bending, etc). If you really want that much power, I'd suggest a small dirt bike or motorcycle. The motor I got is the "Cyclone 3000" which is rated at 3,000 W. So far that's more than enough speed and torque for me.

Chainsaw

Mostly kidding about this one. You certainly can take apart a chainsaw and strap the motor onto your bike to make it go, but it's probably a gas motor (not electric), so it doesn't belong in this Instructable.

Step 3: Bike Tools

First, let’s take a look at tools. The number of tools you will need depends on how much you plan to build a bike up from parts as opposed to buying an off-the-shelf assembled bike. Unfortunately, bike tools are fairly specialized, so in many cases you can’t just “make do” with the tools you have already. Here is what I'd consider the bare minimum toolset for this project:

  • Metric allen wrench set
  • Adjustable wrench
  • Chain breaker
  • Bottom bracket tool
  • Crank puller
  • Socket wrench with metric sockets

If you’re someone like me and bikes aren’t your lifelong passion, I’d suggest getting an inexpensive set of bike tools that covers most of what you need. I got this kit from Luna Cycles for $40. Nothing in it is high quality, but the tools do the job. Compare this to a comparable ~$200 kit from a high quality company like Park Tools, and the value of the cheap kit becomes apparent.

Step 4: Bike Parts

If you’ve decided to buy an off-the-shelf bike and convert it to an e-bike, you can probably skip this step. On the other extreme, you can buy all the parts you need individually and assemble your own bike. There’s also the middle ground of buying a complete bike and upgrading particular components that are important to you.

This last option is most nearly what I did. I bought a decent, like-new mountain bike on Craigslist for $100, then upgraded the fork, brake calipers, brake rotors, wheels, and tires. The complete list of parts and pricing I used can be found here.

If you choose to build your bike up from parts and it’s your first time, it can be a bit intimidating. To help you get started, here’s a complete list of parts needed for a typical mountain bike build:

  • Frame
  • Bottom Bracket
  • Front Crankset
  • Cranks
  • Pedals
  • Fork
  • Headset
  • Stem
  • Handlebar
  • Handlebar grips
  • Brake levers
  • Derauiller levers
  • Front Derailleur
  • Rear Derailleur
  • Brake calipers
  • Brake rotors
  • Cables
  • Cable housing
  • Rear cassette
  • Front wheel
  • Rear wheel
  • Wheel axles
  • Tires
  • Tubes (unless tires are tubeless)
  • Seat post
  • Saddle

So, this is a long and intimidating list. Some things are definitely worth upgrading and getting right (like brake calipers and rotors). On the other hand, I didn't feel the need to spend time and money on many parts, like nice handlebars or a stem. This brings us to the next (optional) step: finding a donor parts bike.

Step 5: (Optional) Parts Bike Teardown

If you bought a mostly or fully complete bike but want to replace some parts, start ripping it apart! Well, use your bike tools and do it carefully. Rather than write an essay here on how to remove every component, I'm going to suggest you learn what you need as you need it. I used Park Tool's Videos on YouTube a lot to learn some basic bike stuff. If that doesn't work, try some google searching. Finally, your local bike shop is always good for advice and, if you're really stuck, you can pay them to just do something for you.

Step 6: Electronic Parts and Tools

Tools

I don’t think you need any additional electrical tools/parts for this project, but here are some that I found useful :

  • Soldering iron and solder
  • Wire strippers
  • Heat shrink
  • Wire (10 AWG)
  • XT90 connectors
  • Zip ties
  • Multimeter

Parts

There are a couple essential electronic parts needed for this build. They are:

  • Motor
  • Battery
  • Motor controller
  • Throttle

You can certainly add complexity with more components, but that's all you really need.

Motor

Motor types were discussed a little bit in Step 2. The size and type of motor you get will determine how fast you can go and how quickly you can accelerate. Bigger motors come at the expense of more weight, more power consumption, faster wear on chains/sprockets, and more danger to the rider.

Battery

The most common battery chemistry used on E-bikes is Lithium-Ion. I won't go into battery chemistry, so do some googling if you're interested. Most E-bikes use a pack of many 18650 cells wired together to effectively make one big battery. A 18650 cell is just a specific lithium-ion battery that's a little bigger than a household AA battery. You can make your own battery pack, but that would be a whole separate Instructable.

Battery packs are sold with a voltage (in Volts) and capacity (in Amp-hours or Watt-hours) rating. Common battery voltages are 24, 36, 48, 52, 60, and 72 volts. A higher voltage battery generally translates to a faster and stronger response from the motor. More capacity means the battery can store more energy, so it can power the motor for a longer time before needing recharging. Here's an example: I got a 60 V (Volt), 24.5 Ah (Amp-hour) battery. If you multiply those together, you get 1470 Wh (Watt-hours). If I go out for a ride and my motor uses an average of 735 Watts of power while riding, then I can ride for 2 hours before my battery is completed discharged. Higher voltage and bigger capacity batteries are heavier and bigger.

Motor controller

This component is the interface between all of the other components. It controls signals and power to make your motor function as you want it, without damaging anything. Some controllers are programmable, so they have some options you can change. For example, there is an adjustable low-voltage cutoff that will automatically turn off the motor if the battery gets below a certain charge to prevent damage from over-discharging. Controllers are usually rated by the amount of current they can handle. For example, I have a 60 Amp controller. With my 60 volt battery, that means the maximum power the controller can handle is 60 Amps x 60 Volts = 3,600 Watts. This is good for my 3,000 Watt motor because it means that the controller will never be pushed beyond its limits.

Throttle

The throttle lets you control the motor while riding. The most common types are twist throttles (like on a motorcycle) and thumb throttles (which you press with your thumb). This is largely a matter of preference, although thumb throttles are generally considered safer. More on this in the "Safety" step near the end.

Whew. Thanks for reading all that. On to the fun stuff!

Step 7: Assembly Part 1: Tubeless Tires

This was my first experience with tubeless tires. Tubeless tires are exactly what they sound like: they have a similar outer, tough rubber to standard (tubed) tires, but the exterior tire is actually airtight. Tubeless tires require a sealant that kind of looks like watery vanilla pudding to fill any tiny gaps where air might escape.

Some advantages are:

  • The sealant allows the tires to be self-healing: if you ride over a thorn, for example, the sealant will quickly fill up the hole and cure, preventing air from escaping.
  • Tubeless tires are immune to “pinch flats”, where the inner tube gets crushed between the rim and tire, making a long gash in it and causing your tire to rapidly go flat.
  • Tubeless tires can be run at lower pressures (the ones in this project are rated at 35-55 psi, as opposed to some cyclocross tires I have that run 60-80 psi and road tires that can go up to around 120 psi). The low pressure allows the tire to flatten out more on the road/trail, giving you more traction.

I talked to my local bike shop guys, read about it online and then experienced first-hand: getting them set up for the first time is tough, but then they’re a blast. Here’s the process:

  1. Wrap the rims with a heavy tape. I used double-adhesive gorilla tape and it’s worked well so far. Make sure to overlap the tape by a few inches, and press the tape down on the edges very well. It will save you a lot of time if you do it carefully the first time.
  2. Make a small, circular hole in the tape where the valve stem will go.
  3. Push the tubeless valve stem through the hole and secure it with a rubber o-ring and nut on the inside of the rim.
  4. Mount one side of the tire inside the rim, making sure to align the tire and rim so that the “direction” arrows go in the same direction.
  5. Mount about 3/4 of the other side of the tire inside the rim.
  6. Pour ~100 mL of tire sealant into the opening left in the tire. Turn the wheel so that the sealant flows into a “closed” section.
  7. Use tire levers to finishing mounting the tire inside the rim.
  8. Use an air compressor to very quickly inflate the tire. You should hear some “pops” as the tire seats against the rim. You can do this with a floor pump (I tried and failed), but it's infinitely easier with even a small air compressor.
  9. Spin and flip the wheel around to spread the sealant inside the tire.
  10. Repeat steps 8-9 as needed until the tire consistently holds air pressure. It may take a couple tries.
  11. If you absolutely can't get a tire to hold air, it's likely that the tape from step 1 got messed up. Use tire levers to remove the tire completely, pull the old tape off, dry all of the sealant off the wheel, and start over from step 1. Avoiding this is the time saving I mentioned in step 1.

Park Tools has a super helpful video on this process. I highly recommend all of their bike videos. I learned a lot for this project just by watching those.

Step 8: Assembly Part 2: Fork, Stem, and Handlebars

There are a couple different types of fork tubes (the part that goes up through the frame), so make sure you get the one that's compatible with your frame. There are fancy tools for installing forks, but I found a soft rubber mallet, a flat head screwdriver, and some patience were sufficient. This is another one of those steps where I could write a mildly helpful essay of text explaining the installation process, or you could watch a short video and get it immediately.

Here's a decent video from Global Cycling Network to get you started.

Step 9: Assembly Part 3: Wheels to Frame

Once the tires are assembled to the wheels, putting the wheels on is pretty easy! If you don't have a bike stand, just flip the bike upside down so it's sitting on the saddle (seat) and handlebars.

The front wheel (the one without the cassette) goes in between the stanchions (legs) on the fork. Insert a quick-release axle, and you're done! The rear wheel can be installed before or after the chain.

Step 10: Assembly Part 4: Brakes and Derailleurs

I'm not going to reinvent the wheel here (ha!). Here are some guys that do a great job explaining what to do with your brakes and derailleurs. If you do end up getting new brake calipers, I recommend the Avid BB7 calipers that I got. They're high-quality and especially easy to set up because you can adjust them in both directions (on the inside and outside of the rotor).

Install Disc Brakes and Rotors

Adjust a Rear Derailleur

Adjust a Front Derailleur

Adjust BB7 Brake Calipers

Step 11: Assembly Part 5: Motor, Cranks, and Chains

This part took a little bit of figuring out, but it isn't that bad. The main challenge is that the Cyclone 3000 motor is a Chinese import, so there's no official video or datasheet that shows you how it goes together.

Here's a simple video showing the first part of the installation from the folks at Luna Cycles.

Here's one showing how to remove or install a crankset from Park Tool. I installed a 3-sprocket 44/44/32 (number of teeth on each ring) crankset, but the short length of the chain from motor to crankset makes it impractical to shift while riding. I leave the drive chain on the 44 tooth ring, which provides less torque but faster top speed. I find this still gives me more than enough torque. Having the geometry of 3 sprockets instead of 2 helps to straighten the path of the chain from motor to crankset, reducing wear and preventing the chain from jumping off while riding.

After the motor and front crankset are mounted, it's time to install the chains. Using a chain breaker tool, get each chain to the right length so that it has just a little bit of slack when in the most stretched position (but not yet tensioned). For the longer chain going back to the rear cassette (on the rear wheel), the rear derailleur keeps the chain properly tensioned. For the shorter chain coming from the motor, there is a small idler gear with a spring that adds tension.

Step 12: Assembly Part 6: Connect Those Wires!

AHHHHHHH! Is the sound I made when I unpacked the 60A programmable motor controller. Wires everywhere. Don't worry, this looks crazy, but it's actually not that bad. Let's go through this a little more systematically.

  • Most if not all of the wires coming out of the controller are labeled. Ok, we can do this.
  • A lot of the connectors are not going to be used. Manual cruise control, automatic pedal assist, e-brake sensors....these are all non-essential things that you can worry about later (or not).
  • Most of the connectors are unique (in other words, fool-proof). You can try to connect things that don't go together, but the connectors won't fit.

Here is a well-written guide on the bare minimum wiring needed to get the bike up and running.

Side note: sorry for the lack of good pictures in this step. See the above "well-written guide" for some nice pictures.

Step 13: Safety

This project is essentially building a high-power, low-weight electric motorcycle. It can definitely be dangerous to the rider and others. Here are some things I did to make it safer:

  • Wear a helmet.
    • Pretty self explanatory.
  • Upgrade to larger (180mm) disc brakes.
    • Larger diameter disc brakes means more stopping power, so you can come to a stop faster. This is necessary because of the faster speeds (up to ~50 mph) and heavier weight (~55 lb) of the bike.
    • Hydraulic brake calipers offer even better stopping power, but I stuck with mechanical calipers here to reduce cost and complexity.
  • Install lights.
    • Often bike lights are there so other people (and cars) can see you at night. I installed a small, flashing red light on the rear of the bike that lets people see you from behind. On the front, I mounted a large 15 Watt LED headlight that makes it easier to be seen but also illuminates the road/trail in front of the bike.
  • Install E-brake sensors.
    • These can sense if you’re applying the brakes. If the brakes are on at all, they cut off power to the motor. This prevents the scenario where you’re accidentally applying throttle and brakes at the same time, intend to stop, but the motor keeps propelling you forwards.
  • Opt for a thumb throttle over a twist throttle.
    • Twist throttles can be dangerous. If the bike starts to get out of control, your first reaction is usually to hold onto the handlebars tight….pulling on the throttle more. This can turn a slight mistake into a serious crash. This doesn’t usually happen with a thumb throttle just because of its location.
  • Use acceleration ramping on your motor controller (if available).
    • This makes the motor spin up gradually in response to the throttle, making it less “jumpy”. With a large, high-torque motor like the one I installed, it’s very easy for the bike to get out of your control if it accelerates suddenly.

Step 14: Future Mini-Project 1: Battery Box

I originally planned to make a box for the battery and controller as part of the build, but it turned into a more challenging project than I had anticipated. So, for now the battery is in a vinyl bag that came with it and the controller is zip-tied to the bike frame.

Why a box for the battery and controller?

  • Prevent theft.
    • The battery was the most expensive part at $800. Putting it in a locking metal box would hopefully deter potential thieves.
  • It's nicer looking.
    • As you saw in some of the previous pictures, that controller has dozens of wires coming out of it, many of them unused. Putting them inside the box with just a port or two makes for a much cleaner looking bike.
  • Protect electronics.
    • In the case of a drop or crash, the battery and controller will stay protected within the box (with some padding). The box will be bolted to the frame with the "water bottle holder" bolts. This still isn't perfect, but it's much better than the setup I have now.
    • Ideally this box will also be watertight, so it will protect the sensitive electronics from moisture.

How are you going to make it?

I started out on the design with some 0.063" thick sheet aluminum I had left over from a different project. As you can see from the pictures, I luckily have access to some sheet metal tools (a large shear and brake) where I work. I made a triangle-ish shape with the edges bent in, then attached separate panels for the sides. This was my first experience with aluminum brazing and I found it frustrating. It was very difficult to stay on the fine line between getting the metal hot enough to melt the brazing rod and getting it too hot to the point that the metal warped. After some failed attempts, I switched over to a combination of rivets and brazing. I think that I will chalk this up as a failed attempt and start over on the box with my learned lessons.

Step 15: Future Mini-Project 2: Cycle Analyst

The Cycle Analyst is an electronic device that allows you to monitor and control all sorts of fun things on an electric bike. I read some great things about it, poked through the manual, and decided to get one. As I finished up the bike and motor assembly (just about a week ago), I was anxious to get riding, so I skipped the Cycle Analyst installation for now. It has been added to my ever-growing projects list =)

Here's the Cycle Analyst 3.0 product page if you want to learn more.

Step 16: Resources

As with most good projects, I couldn't have done it without a bunch of help from the internet. Here are some sites I relied heavily upon:

  • Luna Cycles - reputable, U.S. based supplier of electric parts.
  • ElectricBike.com - partner site to Luna with lots of great information.
  • Amazon - good place to look for parts and get 'em fast!
  • Local Bike Shop - I went to a few different local bike shops throughout this project, and the people there were generally very friendly and knowledgeable!

I also created a google spreadsheet to share:

  • Comprehensive list of online resources I used
  • Final bill of materials for everything used in the build

Well, that's it! Thanks for reading! If you enjoyed this, please consider voting for it in the Instructables Wheels contest. To see some more of my work and learn about starting your own project through my company, check out Thunderstruck Studios.

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3 Questions

how can you drive 50mph with 44-sprocket?
assume you pedal 120/minute = 2/sec, you will reach 16meters/s with 44:11
this is 36mph

Good question, and good math to back it up! You're right, I would have to pedal unreasonably fast to get up that speed. At faster speeds, probably around 30+ mph, I'm not pedaling any more. The motor is providing all of the torque and the pedals are free wheeling (not turning).

So if this is capable of these speeds do you need a licence to ride one? In the Netherlands any motor that is capable of 25km/h requires a scooter licence, not so sure about the E bikes though.

I think that is probably true if you want to ride it on the roads, the same way you would register and get licensed for a small motorcycle. If you stay on trails, I don't think you need a license.

0

Here's the way it works. u plug the charger into the wall power outlet. yours is 240VAC so u need to buy a charger with an AC input of 240 Volts. the battery charger output is DC volts. this DC voltage must be high enough to fully charge your battery. he is using a "60V" battery which actually needs 67.2 Volts from the charger to fully charge the battery. so it is not exactly 60 Volts. Then it depends on how big a battery you are charging; i.e. how many amp hours. The Battery charger is also rated for amps... most simple car battery chargers are 12V and about 10 Amps or 20 Amps. So the next step is: what is your battery capacity? how many amp hours is it capable of? lets say 30 A-H battery. This is written on the battery. its like a bucket with a tap in the bottom. u empty it out and then it takes time to fill it. that's the water u put in the bucket or the charge u put into the battery. it takes time to fill the battery to fully charge it. so if ure using a 10 Amp charger and a 30 Amp-Hour (A-H) battery u need at least 3 hours to charge the battery. actually due to internal chemical inefficiencies it takes about 20% more time to charge it. maybe 3.5 to 4 hours. a good battery charger will stop the charge when the battery is fully charged. This is a must.
So there you have the full explanation. I hope it helps.

Thanks! You can use 240 VAC instead of 120 VAC, but you have to make sure to find a charger that can handle the 240 VAC input. These chargers all have AC-DC converters in them and charge using DC power.

For example, I have this charger:
https://lunacycle.com/luna-charger-60v-450w-5-amp-ebike-charger/
that outputs power at 67.2 VDC to charge my 60 V battery. However, this charger is only rated for 120 VAC input (it says 110 VAC but that's just the nominal term).

You could do the same, you just need a charger that can handle 240 VAC input and still output the 67.2 VDC (or whatever you need for your battery). Alternatively, you could buy a transformer that steps down from 240 VAC to 120 VAC, like this:
https://www.amazon.com/Voltage-Converter-Universal-Adapter-MacBook/dp/B075YQC98J/ref=sr_1_5?ie=UTF8&qid=1516814770&sr=8-5&keywords=240+to+120+voltage+converter

Hi, great article! Thanks for sharing your experience. The gorilla tape on rims. What’s the reason you do this? And, in your photos I didn’t see the tape on the rims. Again, to much!

Thanks! You can see photos of the gorilla tape in pictures 3 - 6 in Step 7: Assembly Part 1: Tubeless Tires. It's a little bit hard to see because both the rims and tape are black.

The tape is necessary to create an airtight seal on the inside of the rim. So, imagine your tubeless tire like a long skinny balloon, except the cross section isn't a full circle - it's more of a semi-circle. You need the other half of the circle (the rim) to be airtight as well.

You can see in Picture 3 of that same step that there are holes in the rim where the spokes attach. All of those holes will leak air unless they're covered up. The tape covers those holes and allows the rim to hold air. You can buy "rim tape" online or at bike shops, but my local bike shop gave me the tip to use gorilla tape because it's cheaper and stronger.

Thanks! You can use 240 VAC instead of 120 VAC, but you have to make sure to find a charger that can handle the 240 VAC input. These chargers all have AC-DC converters in them and charge using DC power.

For example, I have this charger:
https://lunacycle.com/luna-charger-60v-450w-5-amp-ebike-charger/
that outputs power at 67.2 VDC to charge my 60 V battery. However, this charger is only rated for 120 VAC input (it says 110 VAC but that's just the nominal term).

You could do the same, you just need a charger that can handle 240 VAC input and still output the 67.2 VDC (or whatever you need for your battery). Alternatively, you could buy a transformer that steps down from 240 VAC to 120 VAC, like this:
https://www.amazon.com/Voltage-Converter-Universal-Adapter-MacBook/dp/B075YQC98J/ref=sr_1_5?ie=UTF8&qid=1516814770&sr=8-5&keywords=240+to+120+voltage+converter

40 Comments

Thankfully you can't actually get to 50+ mph, because that would be a pretty good way to win yourself a Darwin Award. Looks fun though, I'm definitely gonna take a few reads through it and give it a shot.

Nice project.

Of course it should be pointed out that anyone building, buying, or modifying an e-bike should have a good read of the federal, state, and municipal laws governing them. Many jurisdictions have fairly detailed and strict regulations dictating such things as motor power ratings, top speed, lighting, driver age, licensing, etc. and for example your bike would not be legal in my jurisdiction for at least two reasons. Best to know the rules first and design and build with them in mind.

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Thanks! That is a good point and several other commenters have expressed similar ideas. In hindsight, I should have included a step on legality and explained everything there.

This is crazy fast! I used to sell electric bike convertion kits for a while and always wanted to make my own one. This is really cool :)

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Thanks! What brought you into (and out of) that business?

Small Frame/Wheels is because BMX Frames are very versatile, and otherwise I would've used a Ladies Frame. This (yellow) bike is the Type 10, a.k.a. Fiberglass Shark Bicycle.
My Daughter deserves most of the credit, she designed the Type 9 , a.k.a. Fiberglass Ladies Bicycle, which had 24 inch wheels , but was stolen in 1999. Let me dig up a few photos...
The Type 9 Fairing Design is based on the Rooftop Aerodynamic Spoilers, which are common in the Trucking Industry. The Type 9 Fairing took 300 hours to build, and it's loss was quite a blow on account that I hadn't had a chance to make a Mold from it. The iMac, however was pre-flat screen, it contained a CRT , or Vacuum Tube, and the Plastic Case we know to be certified to meet certain Engineering Standards to prevent the Picture Tube from imploding if struck with a ten pound hammer. I don't want to lecture you on the history of Apple Computers , LOL... But that particular iMac made a good Aerodynamic Spoiler, and the dimensions were very close 15"x15"x15" (height, length, width) versus 16"x16"x16" for the Type 9 .

25268841352_af05808ee0_k.jpg25268831432_2fdc5d3b91_k.jpg25268835652_4d19b24735_k.jpg25398985_1609324912466933_550065486937706437_n.jpg
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That's really cool! I'd definitely be interested to learn more about your fiberglass forming process/method. 300 hours seems like quite a lot for that fairing. Was there one part in particular that took a lot of time? Was there a lot of redesign?

They are called Type Nine and Type Ten for a reason, yes, the design was redesigned 9 times... I can't write an entire instructable about fiberglass, I don't do it anymore, and when I built these, the digital camera hadn't been invented yet (It was , but I didn't have one).
I did have an 8mm Camcorder, so there are a couple of Youtube Videos that I made:
https://www.youtube.com/watch?v=X0akAccfjv4

I watched that video. That's some pretty neat custom shaping you did there.

I've done a few gas motor powered bikes and would like to add a couple things I didn't see mentioned in your instructable.

First, repack every bearing assembly on your bike. They were not designed for the speeds or stress these modifications introduce. The last thing anyone wants is for a wheel bearing, etc to fail at speed because oh overheating or wear.

Also please check with your state motor vehicle laws about motorized bicycles. Some states have age, equipment and maximum speed regulations that can get you a costly ticket.

This can be fun to build and use and a conversation starter when you rids them. But they are still a motor vehicle and need to be safe and legal.

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That's a good idea about the bearings. I've seen a boat trailer fail on the highway and it's not pretty. Have you personally had a bearing fail on you? I built a gas motor bike using a bike that was already ~8 years old and probably rode it over 1,000mi over 2-3 years with no bearings issues.

I just got another comment similar to yours and the laws governing motorized bikes. I do most of my riding on trails, so there isn't much of an issue of riding on public roads. And then, I can program the controller to limit power and/or pedal to fall within the legal limits.

I've never had a bearing fail on my own builds and in the event of a bearing failing I don't mean to imply that it would result in a crash. It could but it's more probable that it might leave you sitting miles from home with a bike that you can't ride home. In many cases the people trying to do their own builds overlook things like bearings chains nuts and bolts. From what I've seen a lot of first time builders start with a used bike or one from a chain store. So the base in those cases should be gone through. I encourage everyone to repack bearings, check chains for wear and adjustment and re tighten bolts and nuts before attempting to ride. Routine maintenance is important too as you are riding something at two to three times it'd designed speeds and for distances greater than normal.
As for legal requirements, check first. In California you must wear a bike helmet at any age for motorized bikes, speeds are limited to 30mph or less, cannot ride a motorized bike on bike trails, etc. Anything might get you ticketed and potentially get your bike impounded depending on the officer involved. Here they will also impound a bike if it isn't licensed. My only intent was to try to give everyone a heads up on things I've learned about potential safety and legal concerns. I included a picture of a $100.00 Schwinn with an import 50cc kit my son and I did years ago as our first conversion. I think there are a lot of these that are first attempts at motorizing bikes for many. Have a good time and keep building (and posting)

Schwinn Right Front.jpg

That's a good point. It's easy to get really focused on the conversion and overlook the details holding the bike together. I'm a mechanical engineer so I'm always thinking about stuff like bearing life and chain wear, but I appreciate the reminder nonetheless =)

I have had quite a few comments on legality - I'll leave my other comments to answer that rather than repeat myself.

I did a very similar gas conversion a couple years ago. Loads of fun and way less expensive! Plus it's still running strong after about 4 years.

Great instructable! small note here, If you operate motorcycles, the problem of panic twist doesn't exist as you are trained not to.

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Haha! Apparently you don't spend much time on YouTube. Twist throttles are the cause of a lot of low speed motorcycle, scooter, and moped accidents. It's a stupid design that only really still exists for historical reasons. IE "we've always done it that way".
The author is wise to advise against them.

That's a good point. I've ridden a gas bicycle conversion with a twist throttle for a few years, but never a "real" motorcycle.

However, I think there's still some safety concern here because the motor is so powerful relative to the weight of the bike. I can't do it justice in words, but the throttle is extremely sensitive and the acceleration will throw you right off the seat if you're not careful.

This is an excellent Instructables writeup and I commend you for the extremely detailed instructions with many photos. I went the easy way and purchased an e-Bike which cost double of what yours cost to make. Mine is limited to about 25MPH and here comes my point. You clearly state that your ebike is capable of doing close to 50MPH. Great. But, that is against the law because you have entered the motorbike world and this would require you to register the bike, have insurance and all sorts of things. You would not be covered for anything in the case of an accident, either. You would also expose yourself to huge liability claims. Besides, I think doing 35-40-45 MPH on a bicycle is just crazy and asking for trouble. But, that is youa and this is me. I enjoyed your article and hope that anyone contemplating to follow in your steps will think carefully about the consequences. Cheers!

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Thanks for your comment! Would you mind sharing which e-bike you have? I'm interested in its capacity, motor size, etc.

I appreciate your safety and legal concerns. I should have made clear in the Instructable that, just because it CAN do 50 mph, doesn't mean I will go that fast, aside from testing it for documentation's sake. I'd say I do the majority of my riding in the 15-25 mph range. I think I mentioned this in a couple other comments as well, but I can program the controller to limit the motor's power and/or the top speed. I totally agree that this can be very dangerous and should be treated as such. I think that riding conservatively, wearing a helmet, and keeping the speed on the low end greatly mitigates the risk.