Endless Sphere

That jack could be used for a charger input, if your signal tracing is correct.

Where the part in the video where you press the center button on the three button handlebar switch? That turns on that model of LCD.

I made that mistake on my first ebike kit. Turned on the battery, no power til I pressed the on/off switch built into the LED display, Seen others make same mistake.

If you only paid the going rate of $398 per bike in walmart.com, it's a heck of a deal. Anyway, I think it's a good start. Your next build can be a monster bike if you want. In 2015, I paid $280 for a 36V10AH pack and $200 for a 500W rear kit. It's got the same 810LED as your Hyper, and I had to sup...

I'd have no qualms converting to a 20A KT 6 FET dual voltage converter with one of their displays. Mine will push 500-600 watts into similar size motor at 36V.

Nice display. Metal case. http://www.bigstone-nj.com/node/12 If they are ignoring your emails, I guess you're screwed. Replace with a KT controller/LCD. You can buy a complete waterproof kit from PSWpower for about $120 shipped, Replace all the cables, sensors, etc. If your motor has a 9 pin cable, ...

BBS02 kits should come with throttle. Some sellers may nickel and dime you, by making it an extra cost option. It is a stand alone part that plugs in, so they can do that.

Lots of hats.

The expensive Euro bikes are one thing, with their proprietary systems and need for diagnostic gear, but the cheap junkers are easy to get running with replacement controllers/motors. It's a question of whether he can get them to pay enough for his time, and whether he can get in a supply of inexpen...

If the packs are going to be separated. I'd do two separate packs each with their own BMS. Then series pack connections add a extra level of circuit complexity, in that if one pack shuts off, the BMS MOSFETS on the other pack has to withstand 84V rather than 42V. I'm sure they can, but parallel has ...

My SW900 looks completely different. Must be different variants in Europe.

I think you're fine with that. Make sure you switch the +5, or the signal, and not ground. Most ebike controllers take off if the throttle ground is interrupted.

You bypass the overvoltage circuits behind the charging port when you come in via the output port. The hoverboard makers were doing that in 2017. With 100K units out in homes, all you needed were a few dozen chargers to go over voltage and cause a rash of exploding batteries. I believe they fixed it...

Only 8 or 9 wires.
1. Ground
2. Battery voltage to display
3. Ignition (which is battery voltage from display)
4. Display serial data in
5. Display serial data out
6, Throttle 5 volt
7. Throttle signal
8. Brake switch
9. Headlights

In the worst case, you cut the connector off your old controller and splice it to the new one. Make the splices inside the controller box for a cleaner look. Without a wire diagram, you'll be doing a lot of wire tracing, Here's one for the display connector. I figure a KT LCD fits the IT4. https://s...

I do agree about only 1-2 mph difference between 13S and 14S in my BBS02.

Hasn't Hailong been a troubled design. Seems to me the contacts would get wet and corrode. Some vendors sold redesigned contacts to fix this. And didn't the packs sometimes fall out too?

In my opinion, the make vs buy choice favors buy when looking at the lower end of the ebike world. There are lots of decent ebikes I can buy for under $800 that I cannot build for that kind of money. You can get bikes with integrated batteries for less than that at Walmart's online outlet, with WMT ...

Is the SW900 one of yours?

I could deal with a 250W motor and small battery. I have ebikes like that, although they're fitted with 20A controllers, so they can do some hill climbing, And I can fit a larger battery when needed. I couldn't deal with just a single speed. Get it out of here.

ERD is difficult to measure on a built wheel. because you need a straight path from opposite faces, and the axle/motor gets in the way. You also have to twice add the extra length of the top of the nipple of the nipple from the edge of the rim. The latter is usually 2-3mm. Probably best to always me...

Depending on what cells they have, those 10S-2P 4AH packs can be pretty good. I have four made with Samsung 22F cells that have been used since 2017. I did have a fifth pack that failed this year. Two cell groups were at zero, probably due to a failed BMS. I had replaced the BMS in two of these pack...

It's not a clear pic, but do your display, throttle, and brakes feed into a single harness? If so, trace the cable from the display til you get to a round connector. Unconnect it, and reseat it. First ebike we ever owned, had a dead display at the dealer. Tech called the importer, and was told to re...

Displays that I've seen are pretty simple. If they get battery power on the power/ground leads they can be turned on. If your display uses a flat 5pin JST plug, you can disconnect it and probe the connector pins from the controller. There's almost always a black wire and that's ground. Probe the oth...

Don't think you will find an 8 speed freewheel that goes down to 11T. DNP makes freewheels that have 11T small gears, but I believe they're all 7 speed.

I had been riding hub motor bikes and one midmotor Bafang BBS02 for two years when I finally got to do some demo rides on mid drive torque sensor bikes at a Chicago bike expo. It was in a parking lot with a track, but they did have a simulated hill to show off the motors. You could get up to a good ...

You're the only one that can tell, but is there a slight dent under the "LB"? You could loosen the spokes 1/4 turn there amd tighten the opposite ones, It won't remove the dent, but the wheel might spin more rounded.