nfsfanat
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Hello. I am from Ukraine . I have experience with electric bicycles and service repair, and I am also writing in hopes of finding someone as a potential sponsor who is as passionate about bicycles as I am and is in the US to help me fill out the I-134 form for the United for Ukraine program.
if anyone wants to help me, my info and email address to contact me will be at the bottom of the post, thank you.
Now let's get to the topic at hand.
For starters, why not buy a pre-made bike?
A ready-made bike is a limitation. Limited in speed, a ready-made bike has a motor built into the frame, and if it breaks, it will require expensive repairs or a complete replacement. Each state has its own electric bike laws. But I originally planned the bike for the woods, desert or rugged terrain, although it's great for the city and will save you from falling on a pothole, bump or bad asphalt, unlike a kick scooter, for example, where any fall can be fatal with more probability.
My last bike I finished already during the war on the basis of the motor BAFANG 750W 48V converted non-native controller 64v 35a and a battery 60v 15a (67.2v), it was an experiment in engine life. I will say right away that with prolonged use, the motor heated up and had to be monitored. But overall it was a viable build that was good fun to ride below will be a video.
It was based on a used dual suspension bike.
Wheelset 27" Kellys
(I don't recommend using a bike without suspension, with a mid-motor engine layout you lose a lot of riding fun)
Part one: the battery.
Why are you so hard to buy?
One of the biggest problems and challenges, I will give as much information as possible, perhaps some of the information will seem boring, but I will tell you why I chose these particular elements.
The task was to create the most compact and efficient battery. As a basis I chose rare 26800 cans with a real capacity of 7000+ mah.
The situation with these elements is very strange, you can't buy them anywhere, I heard that China uses them for the domestic market, I managed to order 48 pieces from China after a long search. They came in blocks of 12pcs that were obviously separated from something, you can't find these cans without spot welding marks. But people I know had already tested them and they performed well. So I decided to take them. Tests are attached.
Test of one 26800 cell with a claimed 6800mah
Link to a battery capacity meter of any type (litokala) on Amazon here.
(China writes that they are made of LI-NMC and resource they have 2000 cycles, but China is China, do not believe every word, I was not able to check and draw my conclusions from the war).
0:00
0:04
We have a 60v battery rated assembly of 16s2p (16 cells in series of two parallels) comes out a total of 32pcs batteries
1pc = 7000mah 4.2v,
16pcs = 7000mah 67.2v * 2 parallels = 14000mah(approximately) 67.2v (maximum charge)
Test check. Everything fits, and there's still space for a charging slot.
For spot-welded elements, we later had to use larger ribbons when further tests with more powerful controllers caused the ribbon to heat up and create losses.
I chose a simple BMC, good quality. I wanted to buy bluetooth. But it was out of stock in Ukraine and I would have had to wait a long time. BMS - DALY 60v 40a
Link to the hi-end BMS manufacturer on Ali here.
This is the holder for the charger connector, which was printed on a 3D printer (not me)
It practically turned out to be 14a. At the claimed 6800mah and actually more.
Part Two: Central Motor
The most important thing is that the engine is powered by the throttle handle, you do not need to twist the pedals, it has an overrunning clutch. Pedals stand all the time
I have worked with several types of motors. Gear motors and direct drive motors too, but not about them yet. The former are the ones that integrate into the frame and are designed for a specific frame.
The latter are those that can be put on almost any bike. I'm leaning toward the second option because one type of motor fits many bikes and has the same parts, which are easier to find.
I chose the bafang 750w because it is common, it has adapters for any BCD, and you can put your own stars. You can also buy parts for it almost everywhere, I agree that these motors are not for 60 mph, but you can get hurt on one of them too.
(By the way maybe in my next post, I'll tell you about the 90v single gear bafang).
MID 250w
An attentive person will see that the motors in the photo are 250w. They differ internally in the size of the motor winding, the number of magnets, have small differences in design depending on the year of manufacture and generation, a different controller that will show an error if you connect 48v. But few people know that most of the parts are suitable for 750w. They were imported to Ukraine in large quantities from Europe. They have been used but are like new inside. We have done various experiments with them.
Link to BAFANG 750w on Amazon here.
By the way, when I got to Europe after the war, I saw very familiar motors, on local rental bikes.))
Advantage of the motor and the ability to purchase an adapter to fit any size or type of star. By the way, this bike also has a non-native controller. BAFANG 250w
Link to the adapter for 104/130 bcd on Amazon Here.
I had a standard Bafang sprocket with 48 teeth. And even with it, several people rolled over on their backs and my dad broke his finger. If the sprocket had been smaller, like the red one in the photo, the bike would have started moving even faster.
New cassette
About transmissions. One of the main advantages is the ability to use gears. You can go up any hill. You can shift in a straight line. Also, using gears is very good for battery consumption. You can get very good results just by shifting gears. I also have a lot of thoughts on the planetary hub, but maybe about that another time.
In addition, the shifter on the handlebar is located on the right, but I already have the throttle grip there, solved the problem simply, turned the shifter and moved it to the other side of the handlebar. I did not feel any discomfort. It was only then that I realized that I had to buy a Grip shift)
Part three: electrical components.
The throttle handle with voltmeter and off button. The headlight of the bicycle is also switched on from this button.
Link to the gas handle with a voltmeter and a key on Amazon here.
The first thing was to disconnect everything in the motor from the bafang, leaving only the motor, and the outputs to the hall sensor. A new throttle knob was chosen, there are such with a key, but for me it is enough just a button, the main thing that would display the value of volts, that would know how much way left.
67.2v full charge
48-50v full discharge
Second, I wanted to solve the light issue and have a phone charger.
I decided to buy such a converter, where one usb input was used for lighting, and the second was always free for the phone or other devices. It is also convenient to have a button with which you can turn off the flashlight during the day. Works from 9v to 90v
Link to 2USB hubs 9-90v on Amazon here.
The controller was chosen sine wave type, universal at 48-64v nominal, 35а 1000w (this is even a lot, it is better to take 30 amps or even a little less).
Charging
Bought the charger 60v 16s 10a, battery is not heated at all, full charge in an hour and a half.
Minus one large size
Conclusions
The bike turned out to be lightweight, fast charging, a lot of fun with a reasonable approach and a budget of less than $1000 (). A great option for the city or for small trips, my dad kept it for himself. Fuel is very expensive right now, and it's practically free on electricity. The bike was planned for fun, but it turns out you need it every day out of town now.
Trying to run up the stairs. Only then did I realize that the wheels were deflated. By the way, after this video, a rocket struck nearby.
A short video about the bike's capabilities.
Cruising range 50-70 km\30-40 miles, you can save on the go by changing gears, then the mileage will be more.
Of the minuses - the motor can get warm if the gear ratio is 11-48 stars, but if you use it, for example, not in the heaviest gear, but in the penultimate gear, the consumption decreases and the motor does not get warm. In general, you can remove the sprocket at 11, since it's going 50 km/h anyway. (31,1 mph)
Link to a battery capacity meter of any type (litokala) on Amazon here.
Link to the hi-end BMS manufacturer on Ali here.
Link to BAFANG 750w on Amazon here.
Link to the adapter for 104/130 bcd on Amazon Here.
Link to the gas handle with a voltmeter and a key on Amazon here.
Link to 2USB hubs 9-90v on Amazon here.
My other bikes equipped by me
Again, for those who would like to help me fill out form I-134 for the United for Ukraine program and are in the US. Or other suggestions.
A little bit about me if anyone wants to help. I'm 24 years old, unmarried (I got my master's degree in electrical engineering, electrical and electrical mechanics two months before Russia started invading Ukraine) I really love bicycles and would like to develop my skills and work in this field in the future.
(This form is required in order for someone with Ukrainian citizenship to be allowed to live and work in the US. Without this form I cannot even apply for consideration as a candidate.)
Please respond to email artmikh12@gmail.com
Thank you for your attention to this post.
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