EBike Conversion - Coffee Hauler

I was interested in eBikes and have seen the kits on Amazon and eBay for a while now. My favorite Starbucks closed and the next closest one was downtown. Close to home but not easy to park. I decided to build an eBike that I could use to go get coffee in the morning quickly.

I picked up a suitable cruiser bike on CraigsList for $65 bucks to get started.

I've seen so many eBike conversions where people just pile the battery and controller on a rack in the back and tie wrap the heck out of the cables. I wanted something clean and streamlined as part of my finished project so I know I had to hide everything in the frames center.

Step 1: Supplies, Parts & Tools

I ordered what looked to be a good kit from Amazon. I decided to go with 48V from what I read on the web. WATTS=POWER the higher the voltage, the more power your going to have. Also the more the battery is going to cost. So I went with a 56v Battery.

I decided on a 17ah capacity. Expensive and Ah=$.

Since this was a cruiser it only had a coaster brake. The kit allows for a front disc so I ordered an inexpensive front disc brake. The motor kit came with brake handles so I already had that.

I hate poorly ran cables so ordered all the necessary braze-ons for the frame as well as the front disc brake bracket.

I also HATE kick stands. I don't like the crappy bolt on ones and I tried (and returned) two leg motorcycle kick stand. I wanted a Schwinn kick stand - which is welded to Schwinn frames so I decided to make my own. I bought a mini-bike kick stand and figured I would use that.

Step 2: Adding the Braze-ons for the Frame

I ordered all of the braze ons from:

https://framebuildersupply.com/collections/braze-o...

Great place - can recommend.

I have a torch and know how to braze/silver solder so I was able to go this route.

Added cable guides for the brake cable and power cable for the motor on the front forks.

Added multiple cable guides on the inside of the downtube to route the cables to the controller.

And I added a rack mount on the left chain stay for a side bracket that I didn't end up using.

Step 3: Making the Bracket for the Battery & Controller

By far this was the hardest/tedious part.

My first fail here was trying to braze/silver solder the parts in. I should of welded them. Not the cleanest looking at all, does look better when painted and hid behind the aluminum side covers though~

I used various gauges of sheet steel for this.

My one suggestion to anyone reading this:

Don't worry about trying to save weight on these brackets. Go for a thicker gauge of steel that is easier to weld into the frame. The total weight of the bike won't be affected that much - the battery and motor weigh WAY MORE than everything else.

Step 4: Making the Side Covers & Fitting the Battery

I used some good foam for another project to protect the battery. Originally I wanted foam on the left and right side of the battery but that would make the overall width of everything wider than the frame. I was trying to stay as close to the width of the frame as I could. My ride to Starbucks is short and smooth so I figure I have enough padding.

For the side covers i used aluminum since these pieces could be removed.

For the controller mount it was a simple matter of using some flat steel welded to the top tube to be able to attache the controller to.

Since I was going to have side covers in aluminum i need to be able to attach and remove them. I figured out after taking a month break on the project how I wanted to do this. I decided rivet-nuts would be the way to go. I created some 'fingers' from the side panels with rivet nuts in them that I could use to bolt on the outer side covers. I had thought about drilling/tapping into the frame at various points but came up with this idea instead.

Step 5: Aluminum Side Covers

I mocked up with poster board what the covers should look like - multiple times.

Once I had the shape I was able to exactly find where the rivet nut holes where and was able to poke a pencil through them on cardboard to EXACTLY know where I needed to drill.

I traced the side cover templates on to the aluminum pieces. Measure 10 times cut once :-)

I had to buy a Harbor Freight crappy band saw to cut the aluminum side pieces. Use tin snips or a jig saw would of made the piece look crappy. The band saw was the perfect tool to do this. Actually the two pieces of aluminum cost almost as much as the band saw.

Step 6: Kick Stand

Man... this took WAY more time than I wanted.

After futzing around with getting the mini bike kick stand bracket brazed to the frame (again, should of welded it) I started to figure out how long, what shape it should be. I had a piece of ornamental 1/2" square stock laying around that I figured I would use. I drilled a hole it it to match the pivot pin on the kick stand and started to figure things out. Ended up I needed to put a bend in the stand to keep it along the chain stay line and not stuck in the wheel. Then I cut it too short and had to butt-weld a new piece of 1/2" stock on it in the process as well.

I wanted to make sure that the stand would keep the bike upright if the forks where turned all the way either to the left or the right without tipping the bike over (Important!)

Then the original spring and mount weren't sufficient to keep the stand up and I add another spring at a different mounting location to keep the stand up and not dropping down when riding.

To finish it off, I added a pad at the bottom of the stand for some extra area on the bottom - AND - so I could 'kick' the stand out with my foot when I wanted to park.

Step 7: Shortening the Wiring and Routing It

If you look at the picture on the left, that's what the original wiring looks like when it's just hooked up. What a frigging mess!

If you look at the picture on the right. The wires tied up all together on the left are the ones I DIDN'T use. The ones on the right are what I ended up using.

Also the manual was crappy at best but it turns out wiring it up is pretty easy.

I used:

Battery wires from battery to controller: (Yellow connector).

Left brake connector: (purple black). The brake handle along with using a cable to the disc brake has a micro switch in it that will interrupt any power driving the motor. So you could be at full throttle and put on the brake and it will cut the power from the controller to the motor. Good feature.

Wires from the controller to the hub motor: (Blue/Yellow/Green wires Black/Red connector - motor power) White connector - additional wires to the hub motor.

Wires to the Throttle: Black connector

So I had to shorten EVERY wire so that they fit nicely and properly into the frame. I also didn't like the twist throttle that came with the kit so I ordered a thumb throttle. Turns out these kits are all the same so the wires on the thumb throttle matched my original twist throttle.

Step 8: Painting

I didn't want a rattle-can paint job on this so I spent the extra time and money to step things up a bit.

I paid to have the frame,fork & chain guard bead blasted. I actually had to. The flux from the brazing/soldering doesn't clean up easy so the only way to remove it is to bead blast.

I went with Hot Rod Flatz paint since I've used it in the past and it is easy to mix and use. It's a two part paint/activator that comes with the kit. I actually paid more for the paint than the doner bike.

I primered it with Rustoleum automotive primer which I've used over the years with great success. I've got some bikes I've painted 10/20 years ago that the paint is still sticking when I used this primer.

I picked up a 20 buck Harbor Freight paint gun (I already have a compressor). Mixed the paint - 50/50 paint/activator and went to town.

I found everything around the house I wanted to turn purple, hung it out on a line and painted it.

NOTE: Don't forget to:

Tape the races for head seat at the bottom of the fork and threads at the top

Where the bottom bracket races set

Inside the seat tube.

The extra paint can make putting the races on a challenge. I actually broke/split a bottom head set race because I had painted the area once. Lesson learned.

Step 9: Coffee Cup Toter

Ok, the sole purpose of this bike was to go get coffee from my down town Starbucks. I needed a coffee cup container to do this. Since me and the wife order the same thing every time I decided to make a dedicated cup holder for our cups.

Picture on the left - Phase one. I consider this a proof of concept. Ugly, hated it. No bueno.

So after taking yet another month off thinking about this problem, I decided I didn't want the cup holder on the top of the rack and figure it would look better on the side. Make or buy? I found some good looking motorcycle side bags for a reasonable price on Amazon and decided to move in that direction. The first bags I bought were too small. I knew that but I have free returns at Amazon and I liked their look. The 2nd bags - the ones shown here were just big enough (with some stretch on my part).

Fired up Rhino Cad and Correl draw, dusted off my eBay laser cutter and went to work.

Since the bags hanging from the rack are flapping around and can bounce off the spokes, I made some side pieces for the rack out of 1/2" tubing. Smushed one end and put a hole it it to mount to the rack mounts on drop outs. On the top I cut a piece of 1/2" tubing and brazed it at 90' to the strut. I used a hose clamp to mount it to the rack. Not the most elegant but you can't see it when the bags are on it.

After wasting a tremendous amount of ply board working on different designs and wrong directions - and taking a break from the project - I ended up with what you see now.

Step 10: Summary

I'm happy with the results. It does what I made it to do - be able to carry coffee from Starbucks. I didn't need such a large Ah battery for a 1 mile a day coffee toter, but I have plans for a 2nd eBike that needs to be able to travel some distance so it will come in handy later.

Comments

[JayGee59]

SO, you didn't say anything about how you start with this. Do you use the pedals to start? Do you keep your feet on them all the time? IF you don't use the pedals - why keep them?

And, YES, nice job!

[etriker]

Federal bicycle laws require that a motorized bike have operable peddles so as to avoid being classified as a moped which requires insurance and a license plate.

[cormack1189]

If it is over 50cc, 49cc only requires, a driver's license, and registration ($75) your sticker is good for 2 years. You can always bore it out later on and no one would be the wiser.
At least in Massachusetts.

[chimewizard]

In Australia the maximum permitted power* (most States/Territories) is 200W without pedal activated control, 250W with. At those low powers you usually need the pedals at some point. Also, if you run the battery flat or there is some other electrical failure, pedaling is still better than pushing! [*Doesn't stop some people fitting two stroke engines that I reckon deliver 1kW+, judging by the way they whizz along (noisily!)]

[r570sv]

I will pull forward from a dead start. I was surprised on how powerful the motor really is. Although you might not want to do that. You might not be balanced yet.

One thing in the kit I didn't use is the 'pedal assist sensor'. I guess some countries require this piece. It's a hall effect device that connect to one of the crank arms and will detect if the crank is turning (you pedaling the bike) and won't let the motor run until it sees that. So basically you have to be pedaling under your own power for the bike to move. If you don't connect it, the controller just ignores it - thank goodness.

Also, It's ugly and required a gizmo around the crank with more wires ran up the frame to the controller so I tossed it out.

One down side to not using it is that if you leave the bike on (on off switch on the throttle) and bump the throttle or thumb it by accident the bike will move forward.

Why keep the pedals? Because I know there will be that time when I get someplace and the battery will be dead, a connector will come lose, the controller will fail and I will need to pedal back.
But you could remove the crank, chain, etc. and put some foot pegs or something in place. And if you add more capacity you can travel farther.

[MiroslavS21]

I way a passenger in a car yesterday and even though i wasnt using my legs, i decided to keep them in case we run out of petrol... ;)

[EagleeyeGamer]

Is this a front wheeled bike? bc like why not make it assist the back wheel thro the chain like I've had i deas, but its always been powering the back wheel, i also had it being gas powered tho, so it rly wouldn't be a "E-Bike" u know?

[r570sv]

It's a coaster brake bike so it wasn't setup for a rear derailleur or brakes. I could of added a rear hanger and post for brakes but I didn't want to - or set it up for a single speed. The gearing is good and I like the simplicity of the coaster brake - no cables/adjustments.

[Overlord_Laharl]

first off its a good guide.
but one thing i have noticed
step 1 "WATTS=POWER the higher the voltage, the more power your going to have" is a very fuzzy statement, and has no real meaning cause by power means nothing in electricity. i think you mean torque.
higher voltage = higher torque (and slower)
and higher amps = faster
so both are important
oh and 1 more important equation Volts*Amps=Watts (thats the simple version that dosent use Ohms)
watts is actual Electricity used or lost (your electric bill is billed is kW (or kilowatts, aka 1000 watts).
heres a couple of things you may want to read
electricity water anology (its a great example of how electricity works) https://learn.sparkfun.com/tutorials/voltage-current-resistance-and-ohms-law/voltage
and this article on motors https://www.jameco.com/Jameco/workshop/ProductNews/motor-buyers-guide.html

[TJLee089]

1. WATTS=POWER is correct. It is not at all fuzzy. Power is the rate at which energy is transferred. Watts is the rate at which electrical energy is transferred.
2. Higher voltage delivers more power through smaller wires, which could result in higher torque, depending on what the power is used for.
3. Higher amps at same voltage means more power. Could be used to go faster or to climb steeper hills.
4. Electricity is NOT billed in kilowatts (which is power). It is billed in kilowatt-hours, which is energy used.

The OP got it right!

[chimewizard]

TJLee089 - all correct. To be pedantic, the SI unit for energy is Joule. Energy per unit time is power. 1 Joule per second is 1 Watt - which is also equivalent to 1 Volt x 1 Amp = 1 Watt, for electrical power. kWh converts back to energy by multiplying power by time - one kWh = 1 kW for 1 hour = 3,600,000 Joule. For an electric motor, crudely speaking, what you get out of it is a function of current in the windings. The volts 'push' the current through, so to speak.

[TJLee089]

Nicely summarized. I see similar misstatements frequently on various forums I participate in. Voltage pushes amps through a wire with resistance like pressure pushes flow through a pipe with friction (or head).

[Sterculius]

I was always taught the voltage hurts but amps kill!

[uche_jonah]

Nice project,but I thought the battery cover should have been painted as well,that will make the bike look more awesome.

[auto13142828]

Why not put some sort of grocery carrier on the back so you can avoid car trips? I sure you could carry coffee in it too.

[charlessenf-gm]

A masterful build, lots of worthwhile information.
" I decided to build an eBike ... to .... get coffee ... quickly."
Your rationalization, however, laves much to be desired.
Get a French Press and some decent grounds, save time, money and get the best coffee you can afford consistently.

[r570sv]

Well, I needed an actual reason, even if it was just that small to justify the build to my wife! Since I get 'our' coffee now she doesn't have to take turns trying driving over and trying to park when it's her turn it was a benefit for her not to do it anymore!

[charlessenf-gm]

"... she doesn't have to take turns trying driving over..."
Please say you weren't driving to a store to pay too much for two cups of coffee every morning!
Before I turn out the lights and go to bed, I put fresh grounds in the SS French press and set the container of water in the microwave before I go to bed. By the time I wake, my wife has heated the water to boiling, poured it over the grounds, stirred the mix gently and put the strainer and lid in place - ready for my first cup ;)
Different strokes!

[MrHermito]

That's what I try to do every time... no, I need to build a standup arcade cabinet so that you can use the TV. Oh don't worry about the holes on the wall, it's an intercom system to wake up the kids easier in the mornings lol

[FredinBoise]

Awesome effort.
Am jealouse of your abilities.
So what's your range with this bike?
How much does the grade of the street effect it?