Opinions on these ebike kits.

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#1
I'm a.returning member, haven't posted in a long time, with life and 30+ other websites. I'm at a point where I need affordable transportation other than the city bus and regular bike. I'm trying.to save up to fix the transmission in my car thus I don't really want a gas kit that needs...gas...and more fiddling than a chinese scooter, plus the initial purchase cost(yeah, I'm being super miserly, gotta fix my dream car) So I'm looking at these 48v 1K watt wheel motors on Wish. Would they be worth it to get? Sorry, the site won't let me use the link imbed feature, every time I tried to paste the link, the blasted thing closed on me.

https://www.wish.com/c/5a0434daa5419b1746b09f1c
 


bakaneko

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#2
The cheap ebike kits that do not have a display only the throttle led do not have an useful peddle assist sensor (PAS). On these kits, the PAS is set to max amps which is impractical, dangerous, and will drain your battery in minutes. You could of course only use the throttle but part of having an ebike is experiencing the PAS. Also, an ebike setup is more expensive than gas due to the battery needed. It all depends on the purpose of your ebike. If it is to workout and have a little assist than a small battery might be sufficient but if it is to replace a car or function as a gas motorized bike than you will need a lot of expensive batteries.
 

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#3
I don't need pedal assist and I don't think it's neccesary. I'm a beast on a bike. I don't even think those have PAS unless that's what that "hall effect' thing is, it mentions. Think of a moped; pedals or motor, but in this case a hub motor versus a stressed out 50cc 2t. I can always get better batteries. I just need the motor for going 20+ miles. Otherwise It'll just be pedaled.
 

bakaneko

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#4
They do have PAS; it is just set on MAX amps. I say this because I have the same kit (36V 500W) and using the throttle for an extensive period of time hurts your hands. I like to bike far distances 100 miles+ and its not comfortable. PAS avoids this by using your pedal cadence along with the power setting as a throttle. These motors are almost bullet proof but there is some cogging (resistance) from the magnets when you don't use any juice; you will feel it more with the 1000W motor. I like my ebike but it ain't the same as my 4stroke gas bike unless I double/triple my 600Wh battery. Just make sure you know the cost investment needed to achieve what you want. Definitely, you can do more pedaling and slowly build up until you get there.
 

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#5
I used to own a scooter, the throttle won't be an issue. I will head that info about the magnetic resistance. I'm glad to hear the motors are decent and if the controllers are crap, I could probably attain something better. I'm seeing the investment thing and quite frankly I've never been a fan of EVs, I prefer gasoline, diesel... steam. But I've always been intrigued by them and try to think of ways to improve them, I have designed some and have a few I want to build. I am decent with electrical work.

I wonder about the top speed, too. It seems the batteries and controller has a hand in that. Also the kits on wish seem to lean toward the use of rim brakes, not knowing top speed, I had the forsight to plan front and rear dual caliper setup and that is with the consideration of how much "engine braking," these may have. Which is also why I've considered suspensionsion for the bike I want to use. I'm thinking my Schwinn Link will be a good choice and I'll be using the Rock Shox Judy off my GF Kaitai. I'm hoping for about 35-40 mph. I have a set of tires that may work too, but I may look in to something like Thickbricks or Slickbricks.
 

bakaneko

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#6
Listen, I am not picking on ebikes. I am a clear adopter and supporter on many, many levels. But, to do what you want to do you have to be realistic about the cost requirements. Here are a few points.

- The cheapest eBike kit throttle is not like a moped/motorcycle/gas bike throttle it is awkwardly oval shaped with round protrusions that gets irritating and slightly discomforting after a long time. The kits with the PAS display is only like $30-50 more. It is worth getting that so you can avoid this throttle if you need

- Lithium batteries (don't even consider other chemistry) come in two grade normal and high discharge. The normal ones are cheap but have a nasty reverse log negative discharge (A) and capacity curve (Wh); meaning the more amps that you draw the lower the real world capacity. The high discharge batteries (rated to 20A) do not have this problem (only 5-10% decrease in capacity) but are of course pricey

- To hit 35-40 top speed, 1000W is not enough. I am a twig (super light rider) and when I had my 1000W I only hit 30. Guys on YouTube with the speed you are looking for are at 1500W minimum and they do not cruise at 35-40. That is a top speed. To do that at cruise, you will need much much more.

- The good thing about eBike especially a hub motor is that you can put it on almost any bike

- I like to minimize tire weight and get the lightest tires for eBikes since there is not that much power and tire weight to rotational force is to the second power I believe.
 

FurryOnTheInside

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#7
I have been looking at a 48v 1000W hub motor too. The cheap softpack 13Ah battery (624Wh?) I was looking at costs £220 (+£7 delivery) and (especially because you can't drain the battery to 0% or charge to 100% without shortening its life) would power the motor at its full output for.. Ooh less than 30 minutes! :D
So, yeah, that's why I haven't got an electric hub motor. :rolleyes:
 

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#8
Listen, I am not picking on ebikes. I am a clear adopter and supporter on many, many levels. But, to do what you want to do you have to be realistic about the cost requirements. Here are a few points.

- The cheapest eBike kit throttle is not like a moped/motorcycle/gas bike throttle it is awkwardly oval shaped with round protrusions that gets irritating and slightly discomforting after a long time. The kits with the PAS display is only like $30-50 more. It is worth getting that so you can avoid this throttle if you need

- Lithium batteries (don't even consider other chemistry) come in two grade normal and high discharge. The normal ones are cheap but have a nasty reverse log negative discharge (A) and capacity curve (Wh); meaning the more amps that you draw the lower the real world capacity. The high discharge batteries (rated to 20A) do not have this problem (only 5-10% decrease in capacity) but are of course pricey

- To hit 35-40 top speed, 1000W is not enough. I am a twig (super light rider) and when I had my 1000W I only hit 30. Guys on YouTube with the speed you are looking for are at 1500W minimum and they do not cruise at 35-40. That is a top speed. To do that at cruise, you will need much much more.

- The good thing about eBike especially a hub motor is that you can put it on almost any bike

- I like to minimize tire weight and get the lightest tires for eBikes since there is not that much power and tire weight to rotational force is to the second power I believe.
I do thank you on your insight. So like NiCad or LiCad batteries would be out of the question? I'm guessing hitting speeds like that would be more emotorcycle territory, than ebike, or something of the sort. Maybe either hub motors aren't what I'm looking for if they aren't for long distance and high speed. I was thinking more about high durability tires, than weight. If 30-40mph was possible, I didn't want them tearing up, or wearing out in two months.
 

bakaneko

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#9
Yeah, those battery chemistry are too low energy density. I believe these two are the latest and best lithium cells. Note, their discharge rate to capacity curve. I would seriously take a look at 1500W+ ebike videos on YouTube to get a sense what is needed. Yes, with the higher power better and tougher tires are needed. Off the top of my head, I think you need a 2000W+ and 60V+ 20aH battery at least. You can figure out the price from that.

https://cdn.shopify.com/s/files/1/0...18650-30Q-spec-sheet.pdf?13304021761413850609
https://www.orbtronic.com/content/Datasheet-specs-Sanyo-Panasonic-NCR18650GA-3500mah.pdf

 

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#10
So the big plan is actually running two of these hub motors a front and rear. They are DC, so they mainly just need enough battery for the power and range. I saw a video where this kid used different batteries and his does like 44 top speed, but has a 16mile range. I'm looking about same speed but roughly 30mi range as a safty measure if the outcome of not being allowed to put it on a bus, or too heavy.

I look at this as an introduction because in the future I'd like to build an electric motorcycle and car.
 

bakaneko

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#11
yes, this is a great way to get your feet wet. i think you need higher volts for the build. there are other experienced ebikers here too so post your plans before buying so we can confirm.
 

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#12
yes, this is a great way to get your feet wet. i think you need higher volts for the build. there are other experienced ebikers here too so post your plans before buying so we can confirm.
From what I just recently found out; two 18650 cells gives you about a mile of fully charged travel. Somebody told me, or I read that one amp hour is about the same. Most of my knowledge of electricity comes from what I can remember from computer tech class in high school and automotive electric in college. Now Tesla uses these cells; about 73/4 in each battery pack for their cars. I saw a youtube video where an ePorsche had I *think* 16 of them and used I believe two forklift motors. Wieght is not an issue with me, I'm not really looking at running 55/60mph consistantly. Just trying to figure out what roughly would yield about a 20mile.range at about 35mph cruising speed and maybe 40 or so flat out. I started looking at a youtuber called ebikeschool, he made a 2wd ebike and said both controllers had to be used and something about making sure the motors sync up by using a device that conmects rhem to the throttle and one sorta piggybacks off the other.
 

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#13
Just trying to figure out how much battery(and cells within) I would need, I came up with this.
-A single 18650 is 3.7v with 3400 mAh

-1000milliamps equals 1 amp

-Supposedly 1aH gives one mile of fully charged travel.

A single battery composed of 10 of these celks should be about 37v with 34,000 mAh.

Two of them working together is 74v giving 68,000 mAh's or 68aH's. Keeping it simple 68aH should be, by what I can figure is 68mi of travel at a consistant Xmph. This is what I have so far. I don't math.

The batteries will be powering(unless one controller could truely suffice) two 1000w controllers running 48v/1000w motors. If I'm right; tbese two motors will be seeing 68amps which I have no clue how many volts that is, since every calculator wants volts amps and watts, whivh is stupid.If I knew all that, I wouldn't need a calculator tobtell me how many watts make a volt or whatever.
 

bakaneko

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#14
- Better to think of batteries in term of watt-hour or Wh
- Two 36V 3.4Ah battery packs in series is 72V 3.4Ah not 6.8Ah but both are 122 Wh of energy
- Look up YT videos on how to properly make a battery pack. I would recommend buying one first, setup the bike, ride it for a while and after you learn more about batteries then make a pack. At this moment, I don't think you should make your own pack
- Use this calculator to determine your minimal voltage and power motor requirements. Note, this is minimal and you should get the next power level to be safe.
http://www.electricbikesimulator.com/calculator.php?language=en#
- To go a top speed of 35 mph, you will need 1500W. To be safe you should plan for a 2000W motor.
- Using same parameters above, for a 20 mile range you will need 830 Wh battery pack but you should plan for 1000 Wh+
- Depending on the battery grade, you might have a negative amp draw to capacity curve. Meaning if you draw high amps, you capacity goes down say 25-35% of rated. This is why you should try to get a higher voltage system or very good batteries
- I do not like duo 1000W motors. It is unnecessarily complicated especially with two controllers you will have so many wires your brain will explode. Get a single rear hub or mid drive motor based on the calculator determinations (remember to go next level up)
 

bakaneko

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#15
I know ebikeschool from YT. He is good and great instructor, but to do what you want you need to be on another level. His videos are good for introduction and LEGAL ebike builders (<= 750W). Your needs is on the level of the 2000W to 30000W ebike builders.

I like watching those high power ebike builders videos but I won't be building one any time soon. I am more looking to build and innovate in the legal (<= 750W) ebike space. But, of course everyone loves to see that 20kW speed burst and riders cursing and having their brains blown off assuming they don't fry their controllers.
 

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#16
I don't think we have ebike restrictions, and I can keep it at a slow pace and hit it if need be. I'm okay with wiring stuff up like two motors, it's pretty easy. Starting with one is a good idea, though.
 

bakaneko

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#17
Take a look at the high power ebikes on YouTube. Like they are pretty much all one big rear hub 1500W+. Unless you cannot get one of these 1500W+ kits then I would start working with a 1000W and overvolt it. But, if you can get one of the 1500W+ I would get a 2000W or something. Take a closer look on YouTube for high speed ebikes.
 


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