A few questions for a new e bike builder

[PowerSet]

Hey everyone, newbie to e bikes here, but a big diyer of most things, and I just have a few questions I can't find specific information on.

The plan is to build my e bike in two stages, a front wheel/motor and existing batteries is stage one for cheap and immediate use without expecting good performance, and then in 6 months or so I'd like to add a separately powered mid drive and upgrade the rear wheel and brakes at that time, making it a much more useful bike.

For right now though, to get me less than a mile back and forth to work, and to keep this cheap enough to justify doing in the next week or two, at this point is looks like I will be going for a 12" scooter/bike wheel/motor, I see them everywhere "brushless gearless hub" with a green ring around the rim, it looks like they are 350w max, and capable of running on 36v.

My bigger concern at this point, is that the existing batteries I have are definitely a poor choice for an ebike because of their low capacity, but I only need them to be enough to assist me about 1 mile a day, I expect to be pedaling to start and just using the motor to cruise most of the way which is not a steep incline, but also not level.

The batteries I have are 36v, I have three batteries, a 2mah, the best I have is a 4mah from the manufacturer, which seems to last longer than the cheap eBay 6mah battery I also have.

Does anyone with a little more experience think a good 4mah 36v battery is capable of doing regular trips under 2 miles? If not, I can get more fairly cheap, and can justify getting them since they also run my lawn equipment, and although they aren't great I could get 2 more of the 6mah knockoff batteries, and maybe run the 2 or 3 6mah batteries in parallel for hopefully 10+ mah realistic capacity, and hope that's more than enough.

I'm open to any suggestions, I do plan on going with a higher voltage and much higher wattage when I upgrade the rear, but for right now I'm hoping to spend around 200 between a 12" scooter wheel ($85), and either a kit for under 100 from Amazon that appears to have everything needed for a 36v setup except for batteries, motor, or a bike, or I may try to spend half that, and hand pick a very cheap speed controller, throttle, and display.


When it comes to the different kits, motors, etc. Is everything fairly standard, or will I be hacking things up to mate the many pinned plug from a scooter wheel, to a speed controller for a bike? And other than the motor chain and sprockets vs a hub motor, are the kits for a mid drive setup the same as kits for a hub motor setup (is there any reason not to buy a complete kit for a mid mount chain drive motor, and use the controls and electronics to power a wheel hub motor(assuming the controller is for a brushless motor and the motor being used is brushless)


Thanks for any input.
PowerSet

[73Eldo]

Scooter wheel was what I was thinking for your other post, small and cheap.

I'm no expert on this sort of build but it seems to me like an area you are going to have to or want to spend some money is on the controller. Something like the Frankenrunner that can pretty much be programmed for anything. I think many of the no name controllers sort of have a programming or learning mode but not with an interface that lets you really dive in and the bigger problem is lack of often any documentation.

https://ebikes.ca/shop/electric-bicycle-parts/controllers.html

I like the idea of trying the lawn batteries especially since you own them already. It would seem like they could work.

[PowerSet]

Scooter wheel was what I was thinking for your other post, small and cheap.

I'm no expert on this sort of build but it seems to me like an area you are going to have to or want to spend some money is on the controller. Something like the Frankenrunner that can pretty much be programmed for anything. I think many of the no name controllers sort of have a programming or learning mode but not with an interface that lets you really dive in and the bigger problem is lack of often any documentation.

https://ebikes.ca/shop/electric-bicy...ntrollers.html

I like the idea of trying the lawn batteries especially since you own them already. It would seem like they could work.

That stuff is probably real good, but a bit pricier than what I was planning. Is there a major consensus that the Amazon and eBay kits are really that bad? I can deal with poor documentation and trial and error, I'm fairly familiar with ripping apart and working on small electronics, including power supplies so I'm not too scared of the electronics or wiring side of things, but obviously if an eBay kit is junk and will break in a few months it's not worth it. However if the kits are "junk" because they're underpowered for most applications, and there is no documentation or support, I'm fine with that.

The particular kit I was leaning towards is the one I've attached a picture of, unless I'm missing something(besides questionable Chinese quality) I should be able to pair that with 36v batteries, and a scooter wheel, and have a complete system.

If mixing a kit and wheel is really that problematic, I would probably go for a better complete kit as I see those for around 2-300 with a wheel motor and I imagine a complete kit would be the easiest route for now(bearing in mind that a good proper speed control and batteries is a planned upgrade either way, and I'm not too worried about "wasting" the 300 on the initial build as I see them as reusable project parts anyway to play with.

[PowerSet]

[73Eldo]

I am for sure no expert on these things and have no hands on experience but from what I have read it takes a bit of luck to get a working motor controller combo because there are so many variables. Even if it does turn will you be getting anywhere near full efficiency and performance? I have watched a lot of videos where people have failed trying to get things to work because the controller is expecting a different number of poles or hall sensors. Some say they can run sensorless but its my impression that that is about the least efficient way to do a motor and you won't get anywhere near the output you could if it was properly matched to the controller.

[PowerSet]

I am for sure no expert on these things and have no hands on experience but from what I have read it takes a bit of luck to get a working motor controller combo because there are so many variables. Even if it does turn will you be getting anywhere near full efficiency and performance? I have watched a lot of videos where people have failed trying to get things to work because the controller is expecting a different number of poles or hall sensors. Some say they can run sensorless but its my impression that that is about the least efficient way to do a motor and you won't get anywhere near the output you could if it was properly matched to the controller.

That all doesn’t sound like too big of a concern since I’m not looking for power or efficiency at all. I’m pretty sure all the components I have found have been brushless theee phase and included hall sensors, but i don’t expect it to be quite as easy as bolt on plug and play.

[73Eldo]

Yes but how many poles does the motor have and how many hall sensors? And how many of each is the controller expecting? I'm not talking about trying to get 2 more mph and 3% range, if things are mismatched bad enough you maybe would only get 10% performance.

I could be wrong and you have a better chance of it working then not working but when I was considering such a project and reading forums and watching videos it seemed like with the cheap no name stuff you never really knew what you were getting as far as the configuration which added to the fun since you also didn't know if your motor worked or the controller. Some of the people that had a big pile of parts and experience were able to recognize certain styles and make better guesses as to what may work and not but many times they just tried different parts till they got a combo that worked.

Like I said I could be wrong since I have not actually tried. Give it a shot and let us know how it goes, if it goes good you can become the sites resident expert on $79 systems.

[PowerSet]

Yes but how many poles does the motor have and how many hall sensors? And how many of each is the controller expecting? I'm not talking about trying to get 2 more mph and 3% range, if things are mismatched bad enough you maybe would only get 10% performance.

I could be wrong and you have a better chance of it working then not working but when I was considering such a project and reading forums and watching videos it seemed like with the cheap no name stuff you never really knew what you were getting as far as the configuration which added to the fun since you also didn't know if your motor worked or the controller. Some of the people that had a big pile of parts and experience were able to recognize certain styles and make better guesses as to what may work and not but many times they just tried different parts till they got a combo that worked.

Like I said I could be wrong since I have not actually tried. Give it a shot and let us know how it goes, if it goes good you can become the sites resident expert on $79 systems.

That’s pretty much the plan, I’ve found very little info other than a lot of people have used them without issues. I’ve got two complete kits and spare parts coming, largely because I mentioned wanting to know how compatible different generic kits are.

[Diggs Ut]

I've built several bikes from the inexpensive ($200-$300) 1,000 watt rear hub motor kits from Amazon and they are still running great. No waste about it. Personally I think that's the economical sweet spot in DYI bike conversions right now. Good power and performance at low prices. (I did have one controller failure and the seller replaced it quickly.) I do build my own batteries as battery packs cost more than the kits and BMSs are cheap. I think you may get frustrated by your lack of battery capacity but let us know how it goes.

[PowerSet]

I've built several bikes from the inexpensive ($200-$300) 1,000 watt rear hub motor kits from Amazon and they are still running great. No waste about it. Personally I think that's the economical sweet spot in DYI bike conversions right now. Good power and performance at low prices. (I did have one controller failure and the seller replaced it quickly.) I do build my own batteries as battery packs cost more than the kits and BMSs are cheap. I think you may get frustrated by your lack of battery capacity but let us know how it goes.

I would love to get one of the kits closer to what you've gotten, unfortunately since I'm sticking with a bike I already have that isn't a good candidate, I think I'm pretty limited in options.


The bike is small enough to comfortably bring up and down the narrow stairs into my apartment, it has a 16" front wheel and has a 20" coaster brake single speed rear wheel(I'm sure my terminology is wrong, cars and electronics are more my area than bicycles)

I believe most of the rear kits I saw were for multi gear bikes, and I am not familiar with, and haven't got much time to learn to and properly re spoke any rims, swap any cassettes, change axles or anything serious when it comes to the bike, so I wanted to stick with finding a front motorized wheel, and keep everything in the back normal. I also had quite a bit of trouble finding anything I considered inexpensive for front wheels under 20", and although I have the room and could probably go up to near 30", I would not like the look much, so scooter wheels seemed to be what I found to fit my odd requirements.

I ended up getting a lot more than I initially intended, as the price was too good to not try a cheap chain drive kit in tandem or on it's own for comparison.(separate power/controller etc. I will probably try pas on one system)
I handpicked a few odd things that would be suitable for my build, were fairly inexpensive, and we're able to be here asap(everything will arrive tonight)

I don't expect much of any power out of this, if after ive gotten it moving, the bike can cruise at like 7mph for 5 miles, I will consider this a massive success. I am not expecting a 25+mph bike that I can ride long distances. That will be either the second bike, or if/when I upgrade everything on this bike.

[Retrorockit]

A one mile commute should be doable while you wait for parts for a proper conversion. I would just wait and do it right the first time. Put the extra money into the battery.

[PowerSet]

A one mile commute should be doable while you wait for parts for a proper conversion. I would just wait and do it right the first time. Put the extra money into the battery.

Unfortunately I’m really just not one of those do it right the first time and be done types. I love to tinker and experiment, and I love to see what really can be accomplished with small budgets. I’ve got a $7 mp3 decoder for a car stereo, and build 12v high amp workbench power supplies from dell server power supplies, so this is as much for a new hobby playing with electronics than it is about having an electric bike.

[Retrorockit]

I'm not one and done either. I'm always trying and upgrading stuff. But buying cheap stuff and playing around can be educational. I've learned a lot that way.
Doing it right the first time costs less is one of the things I learned.

[PowerSet]

I suppose it's worth mentioning(if I didn't already) that I don't expect this to be a practical route. It's to answer my own questions about the cheap kits and getting solid answers and comparisons, to get a cheap toy to get back and forth to work the next month or so while the weather is brutal, and one somewhat key part of this endeavor is to be left with extra parts for future projects. I have a two year old son who would probably get a lot of joy out of a ride on car bike or trike sometime in the upcoming years, and I definitely won't be giving him a 1000w motor with lots of range. But something low power I already have in a box somewhere will be perfect for something he rides, or even a power assisted wagon or something similar.

[PowerSet]

Yeah, but I don't expect a lot of thrill from 350 watts and under. I'm too fat for it to be thrilling lol

[Retrorockit]

Which takes me straight back to the 1500W BBSHD with 24Ah battery concept.All roads lead there eventually.

[PowerSet]

I don't disagree about that. When I've got space to keep a bigger bike, I think a beach cruiser or something similar with 26"+ wheels will be the way to go. For now I'm impressed with the 24v 250w chain drive, so I think it'll do for the last month or so of summer for my tiny commute

[stts]

waste of time

[PowerSet]

I can make anything work. But others getting brushless motors to work is like predicting the roll of a dice. Brush motors are easy for anybody. Plug and play. So if you need easy and cheap, Get a brushed gear motor kit. Hook all the parts on, plug in all the plugs, and off you go. Its just a mechanical job when going that route. Theres no funny electrical sensors or calibration or controller learning.

Good to know. I've actually got a brushed chain drive kit on it now, and still waiting for a couple things to ideally do a brushless front wheel on a separate kit. I am fairly familiar and comfortable with electronics so I don't foresee any big problems with brushless other than maybe the wires from a motor being different colors than the esc, but that's easy enough to trial and error.