Comments by "Two-Row Euro" (@fun_ghoul) on "Are 4-Stroke Bike Kits better than 2-Stroke Kits? Let's find out!" video.
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@stevewilliamson8526 I do my shopping, go home, plug the bike in and it's ready the next time I need it. Oh, and I can charge my battery from empty for US$0.12. How much does your tank cost to fill, Sparky? And how soon do you need to run back to your master, the gas station?
I used to work at a gas station, so let's not pretend that you've never left there with hands reeking of STALE GAS. Maybe you've even had a pump nozzle fail and spray you from head to toe! That happened to about 2 customers a month where I worked, because paying people to shut up was cheaper than proper preventative maintenance (e.g. replacing nozzles after a certain period of time, better means to de-water fuel, etc.).
In short, kid, you're dumb. You didn't merit this reply, but hopefully, the next "you" will see this and think before they pop off.
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@BB-1990 That was a typo, arsehole. My point still remains: For the $420 cost difference, you'd be lucky to get 9000 miles. And again, this is based on the other idiot's fantasy price of $80 for a complete kit. That's literally not gonna happen unless it's stolen.
As for efficiency, my dear dino troll, it will drop to no less than 80% @ 1000 cycles for my li-ion pack, and 90% for my LiFePO^4 pack. These are very conservative estimates, designed to replicate what a "normal" user might get from a poorly matched battery pack, charger and motor controller, which is often what's supplied with a fully-built ebike.
My setup, OTOH, is well-matched, with the motor controller cutting off at 3.3V/cell, rather than the more deleterious 2.5V/cell that Sony tested the VTC6 cells in my pack to. I also charge to a mere 4.08V instead of 4.2V for the same reason. If you search any number of forums where people use li-ion cells (ebike, vape, flashlight, drone, RC, etc.), you'll see that people are getting 1000+ cycles to *90%* capacity with reasonable charging and discharging.
Capacity also drops more when a cell is pushed closer to its power (current) limits, but the VTC6 cell is good for 30A continuous, my pack is 6P (so, 180A total) and I never draw more than around 50A in short bursts (e.g. 5 seconds, taking off from a dead stop).
Oh, and my other pack is a 16S Headway 40152S. Those are good for 150A continuous which, again, I never come close to. Those ones can literally start a car, and will in all likelihood be what I use to power the kWeld I'm buying next month (reconfigured to 4P4S).
How's my math now, bitch? You got the flavour yet???
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@chadingram6390 Sorry for not replying sooner, but I must have said a no-no word to someone because Pootoob blocked me from commenting for 12 hours. I know, you're shocked! (Also, it took hours to type this, between doing other things.) Anyway, that did give me some time to drill down on this.
Can you turn a wrench? Can you operate a zip tie? Great! That's pretty much all you need to install the motor wheel and wiring on your bike. Depending on how ghetto you can deal with your bike looking, you might well use zip ties to mount the controller as well, like I do. Otherwise, there are frame bags that velcro onto your top tube and have a hole for the wires to come out; they make for a cleaner install, but I'm wary of the shoddy manufacture of the bags. Even so, you could use the bag and zip ties to be super secure.
The wiring seems complicated at first, but it's actually pretty easy. There are 5 fatter wires on the typical "aluminum box" controller: red (+) and black (-) go to your battery, and 3 go to your motor (blue, yellow and green; these are called "phase wires"). Along with the phase wires, there will also be 5 thin wires for the Hall sensors (red and black to power the sensors, and blue, yellow and green for the sensor signals, one for each "phase"...notice the colours are the same). There are "sensorless" controllers that don't even need those last 5 wires, but the cheapest ones usually do, and "sensorless" is usually not as smooth and has trouble starting from a dead stop. There are usually a shitload of other wires, but all you really need is the throttle, which will be a 3-wire connector (red=positive, black=negative, white=0 to 5 volt throttle signal). If you want to be super fancy about it, you can also hook up a pedal assist sensor to give you motor power when you pedal, and "ebrakes" to cut motor power when you brake (also for regen, if your controller is capable...this is not recommended for front-wheel drive!)
You don't even need to know any of this wiring stuff if you buy a complete kit with motor, controller, battery and throttle, because it'll have foolproof connectors that can only go one way...but that's more expensive. You said "cheap as possible", right? I grew up in the projects, and my grampa was Italian from the WWII generation, so I know cheap! lol
The battery is generally the most expensive part, but a few things work to your advantage here:
1. You're not a fat pig like me, which is to say, you have less "frontal area" (actual weight isn't as much of a concern as wind resistance).
2. Your desired range is fairly modest.
3. People are pretty fucked for money nowadays, so used things sell for cheap as balls.
Even so, it's better to overshoot a bit on battery capacity because of things like headwinds, hills, added cargo (again, frontal area matter more than weight), and declining battery capacity with use. On that last point, tho, you can help this a lot by keeping your charging and discharging within certain parameters. Namely, for a "normal" lithium-ion battery (so, not lithium iron phosphate, a.k.a. LiFePO4), you would ideally charge no higher than 4.08-4.13 volts per cell, and discharge no lower than 3.0-3.3V/cell. The discharging is usually easy enough to tackle, by using a controller with a low-voltage cutoff that works out to around 3.3V/cell for the pack you have (e.g. an LVC of 33V for a 36V nominal pack, whose fully-charged voltage will actually be 40.8-41.3V). When you hit the LVC, the controller will cut out. Of course, if you plan this right for your proposed range goals, this will happen rarely or never! And, if/when it does, you won't be kicking the shit out of the battery's cell life.
For the charging, it basically depends on what you end up with for a battery and charger. Some will not be adjustable, but those are often fixed at 4.1 volts per cell...that's what we want! If instead you opt for a "real" ebike battery, you'll often end up with a charger that has a knob (potentiometer) inside that you can twiddle to tune the voltage to exactly what you want. Test it first tho, because it might already be in the happy range.
Now, you might still wondering "But what do I buy, asshole?" The answer is...well, it depends! The controller will have a maximum voltage (go over this and you'll blow it) and a minimum voltage (below which it will turn off; that's the "low-voltage cutoff" or LVC I mentioned above), so your battery needs to fall within this range. IOW, you can't decide on a controller until you figure out what you're doing for a battery. You can buy controllers that have adjustable LVC, but these will typically cost more.
To give a proper, thoughtful recommendation, it would help me a lot to know a few things. How familiar are you with electricity? Have you done some soldering? Used a digital multimeter? How low you can go on cost, or rather how much you get for your money, depends a lot on these things. They're not hard to learn, but the consequences of getting it wrong can be dire...like burning down your house! That's no different than gasoline, it's just...different. If you're not comfortable with this stuff, you can defo buy a factory-built battery pack, it's just gonna cost more.
For that matter, if you can put a dollar figure on your budget, that would help a lot! I told the CHUD above that I spent $500, but again, this is with me assembling a battery pack. OTOH, pre-made battery pack prices are dropping fast. It's a bit of a crap shoot because you don't know what cells you're getting unless/until you open it up and look inside; your range goal is quite reasonable, but if you want decent speed, you need cells that can put out high power over and over again.
P.S. At anything over 20 MPH, the condition of the road matters a lot. I presume they're pretty good where you're at, but that's just a guess. Up here, we get potholes every spring, some of which are large enough for a large racoon to crawl into. If you have rough roads, you'll want fat tires (not necessarily "fat bike" size; I run Schwalbe Crazy Bobs, 26x2.3"), suspension or both. With the li'l fatties on a fully rigid bike, it's a rough ride on Ottawa roads at 30+ MPH! If you're already used to the idea of riding "loose" like you would on a motorcycle, which is to say not white-knuckling it, you'll be fine. And again, if your roads are smooth, this will be a non-issue.
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@chadingram6390 "I grew up in automotive so i could re-wire a car with enough time and cussing, but i rarely have to deal with anything more complicated than a simple circuit anymore so i always need to brush up on the info."
This is a great start! In terms of getting wired up, this is a fuck of a lot easier than most automotive stuff. If you can wield a multimeter, soldering iron and/or crimpers, you're golden.
"When you talk about sensorless controllers does this relate to internally geared hubs?"
No. Sensorless controllers can be used with both geared and gearless motors (gearless is also called "direct drive"). Sensorless-only can be jittery, but some sensored controllers will fall back to sensorless mode if one of your Hall sensors takes a shit; this saves your ass if it happens far from home.
Geared motors are basically small electric motors that run their power into a planetary gearset, like in an automatic tranny. They're lighter and have better torque off the line at a given current level (amps), at the expense of more moving parts. The smaller motor also limits the top end, and because all this stuff is in the same housing, it's hard for the motor to shed heat.
Not many geared motors are reliable at 30 MPH, and the ones that are (BMC, MAC, eZee) are the heavier, more expensive ones. If you push lesser ones, you can end up with "peanut butter gear" (melted nylon planet gears). That said, if you insist on the lightest possible setup, geared is the way to go. You'd probably be fine with a Bafang BPM, especially if you can live with 25 MPH instead of 30.
Direct drive is just what it sounds like: An electric motor with no moving parts, so the only things that can go wrong are the Hall sensors and the bearings. They're heavier tho, so handling can suffer a bit (esp. front-wheel drive), and God help you if you have to carry the thing up stairs regularly! OTOH, if you ever want to hot rod it, direct drive is what you need. You can get these to go as well off the line as geared, if you feed them more amps. That means a more powerful controller and battery, of course.
Oh, and direct drive is quieter. With a sine wave controller, it's basically dead silent. My controller is square wave, which I like specifically because there's a bit of a growl when I crack it. This serves as a warning to people on shared-use pathways! In this vein, you really have to be ready to yell at cars on a fast ebike, because they don't expect you to do the speed you are, and will cut out in front of you like a MFer! I'll be adding an air horn soon.
"After looking i really like the value to performance from the 48v 1000w systems available. I also see there are 48v 1500w systems for basically the same price around $250, is this a different motor hub or is it just the higher 26A controller allowing more power?"
Defo the controller. Motor wattage ratings are mostly bullshit. In a perfect world, sellers would just say how the motor is wound (how many times the copper wire is turned around each motor pole), so you can do the math yourself. Or, if you're like me, just plug the stats into the Grin Motor Simulator (https://ebikes.ca/tools/simulator.html). The average motor in the cheap Chinese kits like the one I run are 6 turns or 7 turns, particularly on a 26" rim. In the Grin motor sim, you're looking for 9C+ 2706 (6T) or 2707 (7T) in the motor list; fewer turns = higher top speed at a given voltage. 9C stands for Nine Continents, which is a brand name; most of the Chinese kits are 9C clones.
Controller wattage ratings are also bullshit. The main things to focus on are:
-amps (determines your torque)
-maximum volts (determines your top speed), and
-minimum volts (usually called low-voltage cutoff or "LVC", below which the controller turns off the motor)
"I figured if i'm making the battery pack myself i might as well do a 52v with at least 17.5ah or more."
This is more than enough for your stated 10 miles of range, and 52V should get you right around 30 MPH on the flats. In short, this is good.
"I found some decent LG and Samsung cells on ali express, can get 84 for around $200..."
Aliexpress is fine for a motor kit and mayyyybe built battery packs, but I wouldn't trust sellers to send genuine 18650 cells. Scams are commonplace, where they get any old cell (emphasis on "old"), slap fake name brand shrink wrap on 'em and sell them for what seems like a good price. Not only are you unlikely to get the capacity they advertise, but mistreated lithium-ion batteries can form copper shunts inside. This leads to fire. Fire is bad.
My first battery pack was 4 Ryobi 18V 9Ah packs -- Home Depot was blowing them out for $100 Canadian apiece -- onto which I soldered a few wires. I had them hooked up 2P2S: Two pairs of packs in parallel, then connected in series, which gave me a 36V 18Ah pack. The cells are Sony VTC6, and I was running them without a BMS (which is bad! don't do this!), and I was getting around 25 MPH and 30 miles of range with pedalling on my 9C clone motor (not sure how many turns; I bought it used on fleabay). No regen either, so there's potentially 6 to 8% additional range there if/when I get a controller with regen. That said, my motor is on the front, and regen is a bad idea on the front.
Did I mention I'm not running a torque arm? Again, don't do this! I've been relying on my fork being chromoly, not using regen (which reverses the torque on the dropouts) and tightening the Christ out of the axle nuts. Don't be like me! Even a rear-drive motor on a steel frame is best with a torque arm, and on aluminum, not using one at the speeds we're talking about is suicidal. I'll be making or buying one before the winter is done, and counting my blessings.
"...plus $60ish for nice BMS."
I'm not too up on BMS prices right now, but this seems a little high.
"Do you own a spot welder? I need to find a way to rent or borrow one."
I don't, but I'm considering buying a KWeld to maybe repair packs locally. There are Chinese ones for a lot cheaper, but reviews are hit and miss, and good cells ain't cheap! Thankfully, my current pack has Headway 40152S lithium iron phosphate (a.k.a. LiFePO4) cells, which have screw terminals and bus bars. They're great, but also heavier than I'd like at around 20 lbs. for a 52V 15Ah pack. The flipside is that LiFePO4 has the best cycle life, does higher-amp charging and discharging AND won't spontaneously light on fire no matter what. They will, however, turn a 5mm hex key into a glowing red stove element if you fuck up...ask me how I know! Eesh.
"Is it cheaper to piece out the hub and controller and throttle/brake levers? Do you have any good sources with good prices?"
I'd say this depends on how soon you want to be riding. I presume sooner is better in your neck of the woods, but if you're not in a rush (or need to wait to get your money together), you might look at used stuff on ebay. I looked on there last week after your first message, and there were defo some deals on used batteries. The prices of the motors I saw weren't great with shipping factored in, but similar to Ali with a shorter wait. Also, you never know what deal might pop up! Kits are not bad in the sense that you get all the bits you need (and some you may not, like PAS and ebrake handles), but the controller will probably be wimpy. That said, if you buy a more powerful controller on top of that, you might be able to sell the wimpy one locally to offset the cost.
There are also places like Battery Hookup, Battery Clearing House, etc. who sell used batteries for cheap. Some of their stuff is shagged, but some looks good. I haven't bought from them yet, but only because shipping to Canada is expensive. You'll do better on your end, I think.
https://www.batteryclearinghouse.com/
https://batteryhookup.com/
https://www.ebay.com/itm/48V-12-5Ah-Hailong-Lithium-ion-Ebike-Battery-750W-1000W-Electric-Bike-Motor-US/284152684678 (used battery and charger; seller is in Mesa, AZ..."Best Offer")
https://phoenix.craigslist.org/evl/tls/d/mesa-greenworks-82volt-50-ah-lithium/7242976862.html (also in Mesa; could be good as-is or for rebuilding)
Hope that helps. Oh, and be sure to check out https://endless-sphere.com/forums/ for tons more stuff. Frankly, I probably should have recommended that in the first place, but I didn't want to seem like I was sloughing you off! Cheers.
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