How to repair an E-bike
Hello, I haven't written anything for a while, as it turned out to be a busy days. A few weeks ago I managed to buy a cheap, scattered E-bike to repair. It was a Chinese brand, an E-code, and as for a good Chinese product, it worked, when it was new. I picked up the bicycle from a guy on a social network site. In one box there were screws, some parts, frame separately, and wheels separately. I was worried, only that there would be nothing missing, because as the mechanics can be bought, but the plastics are very difficult to get. So I checked if everything was quite right and packed everything into the car. I managed to buy it for two hundred zlotys, I simply took it blind for such money. The plan was to restore it, if possible, it's going to be something to ride in the forest, but if not possible, then it's going to be a part donor, for another bike that I'm planning to redo.
Luckily, I have enough space in my garage to put this bike together. I will tell you, my dears, that stripping off the chain without a puller is a miracle. After a long murdering hours I went to the store and bought the tool, because it was a waste of time without it. Do you have any ways to unlock a chain without a puller ? The frame had to be cleaned well, with sandpaper, first with a wire brush I removed the rust, because, the frame from the bottom in the suport area started to rust. Yes, this is a Chinese steel, so you practically have to be able to lift yourself well. After the wire brush, it was time for the sandpaper, I started with 400, and finished with 800. I did the same with plastics, of course without a wire brush :) Unfortunately I don't have any pictures from the process of preparation and painting. I don't know, somehow it came out of my head to commemorate this activity. Getting the right paint to paint your E-bike is not easy either. I thought, I will go to a building market, yes, there are paints, but none of them have the right hardness. The car paint store turned out to be the best option, but expensive. I decided to paint my E-bike in black matt, the same plastics. First I painted the whole thing with primer, two layers, on the second day I painted the frame with black math, four layers. When the frame dried up, I thought it was enough, but I was wrong. When the frame falled down on the concrete floor of the garage, the lacquer was not strong enough. I corrected the scratches and went to the paint store to get something right. We deduced that it should add durability to it the clear coatings. Ha, but it wasn't that simple, in three stores I couldn't get a matt clear coat. Next days on the hold. I understand the situation, pandemic and everything closed. The paint came on the third day, I applied three coats, I'll tell you that it fixed the matter. It is a pity that lacquers with hardener are not so available in Poland. In England, when I was painting the frame, I bought such a two-component spray paint in a store. It was easy, just to press from underneath, mix and the paint was like from the factory, for a few years nothing was scratched, here my Chinese-made frame became heavier by additional kilogram of paint:) Assembling this kind of electric bicycle wasn't easy at all, it's different how you assemble your own E-bike when you remember where everything it was. Here I had a box of parts and you can do it yourself :) In total, assembling took me about a full day. Most of the fun with these plastics was to fit them well enough to not break anything and most of all to not shake while riding. The chain came new, all the hubs were washed and greased, 36 volt engine with planetary gearbox, oh worth its weight, these old engines are unbreakable, one thing is that they quietly handle 48 volts, they hardly heat up. Greased, it started to spin even better. The time has come for a saport. Oh, it is not easy to choose a saport for your E-bike when you do not have the old one. Standard nuts, wreaths too, but the length of the muff is only 80 mm. How long I searched for it, how many internet sites I was browsing, how many calls I made.It was worth the effort. Support from fat-bike costs 200 to 300 PLN, so it would suit me, but it costs more than a E-bike. Finally, I found the same E-bike on eBay, called the manufacturer and asked about the size of the saport, and he offered to send it to me, because I won't buy it anywhere anyway. I guess he was right, but for those who will be tired of it in the future it is a 185mm long axis for a 73-92mm muff, bowls are standard BSA 34mm, bowls and garlands in the bicycle store cost 16zl, and the support all 60zl with the delivery. This is how I had a bicycle, which even had a gas handle and was moving from place to place. However, its drawback was a gel battery, or more precisely three of them. Heavy and inefficient :) Since I've already made more than one battery, I decided to go crazy, there is so much space that it's hard to fill it, after three such 12ah gel cells. What's more, I went crazy and made a 10s 10p package. I used all 18650 in capacities from 1600mah to 1950mah. If you would like a cool page to calculate packets, I suggest a "repackr". It calculated me 17mah difference between the packets. I've already written about the 18650 acquisition and testing. As for building the battery itself, I will write a separate article, and there will be an opportunity to do so soon. I want to convert two bicycles in my own way, one is an old Polish Jubilate, which I want to leave for myself and my wife's bike is Kross Diamond. Both bikes have three gears in the rear wheel hub and I will want to use a Hoveroard engine to drive them. So I will have to make two batteries that it will still be 36 volts. It is still a matter of figuring out where to mount them. I do not use BMS in the battery, what I have used is only to protect the battery from excessive discharge, which is the cheapest Chinese BMS. All in all, they are only suitable for this purpose, I checked it disconnects the power supply at 28 volts, but this is still not a problem for me, because I check the voltage and decide when to charge the battery. Having such a reserve of power, I could not discharge it to this state while driving. A few days ago I made such a small trip, about 50 km, on slightly rough terrain, practically not helping pedaling, from 41.5V lasted to 36.02V. Probably I could do one more such trip. Now they predict that the weather will improve, so I'll do some more tests, I'll also want to check how the individual cells behave after a few times charging the battery. I ordered such a clever device, which is called active balancer, for this I decided not to invest with a good BMS. All I have to do is connect it overnight, every few months and everything should be all right.
When I'll check the battery and I'll have it disconnected I'll attach some photos :)
And in this time I greet everyone warmly.
1 Comments
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