Choosing a motor

Hello,

I am planning my next ebike with my Merida big 7 40 with 27.5" wheel and I dont know what motor to choose
I will ride mostly in the city and maybe also off road trails. I want speed up to 45 km/h and because I ride in the city I have a lot of stops so I need fast acceleration.
I thought about Bafang BPM2 48v 500w geard motor but I dont know if it have enough speed and power.
What do you think about this gearless motor ?https://www.aliexpress.com/item/E-b...32322994192.html?spm=a2g0s.8937460.0.0.UxYqWc It will have enough torque ?
I forgot to say but I want to use 13s (48.1v) 13ah Li-ion battery.

Thank you,
Ofek

The motor you linked is direct drive, are you sure you want to go away from a geared motor w/ lot's of stop and go riding?
The sim. @ Ebikes CA shows the BPM CST(Cassette) just reaching 45 Km under it's own power on a bike w/ the parameters you specified. I didn't ck the climbing performance, but it should be ok for everything but the steepest hills.
Put any $$$ you save by going w/ the BPM vs., say, the MAC, into the battery. Panasonic cells, for example. The controller should be in the 25 to 35 Amp range and the type(sine wave or square wave, which display)would be your next big choice.
You could buy everything from BMS Battery or possibly elifebikes(PWS Power) and consoladate shipping costs.

motomech said:

The motor you linked is direct drive, are you sure you want to go away from a geared motor w/ lot's of stop and go riding?
The sim. @ Ebikes CA shows the BPM CST(Cassette) just reaching 45 Km under it's own power on a bike w/ the parameters you specified. I didn't ck the climbing performance, but it should be ok for everything but the steepest hills.
Put any $$$ you save by going w/ the BPM vs., say, the MAC, into the battery. Panasonic cells, for example. The controller should be in the 25 to 35 Amp range and the type(sine wave or square wave, which display)would be your next big choice.
You could buy everything from BMS Battery or possibly elifebikes(PWS Power) and consoladate shipping costs.

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So I think I will buy the BPM motor from here: https://bmsbattery.com/ebike-kit/35...-rear-driving-e-bike-hub-motor-ebike-kit.html
What rpm should I choose ?
And I also saw that if I buy 36v RPM motor with 48v battery it will be faster that 48v RPM motor. this is correct ?
thank you

Just do the math. The DD motor is a 12.5Kv motor. At 48V it will have a top speed of 49 mph unloaded speed. Depending on which rpm you get with the geared motor, top unloaded speed will be 16.5mph with the 201 rpm, 21 with the 260 rpm. and 26.8 mph with the 328 rpm motor. The DD motor can withstand 5KW easily for short periods of time. The geared motor would break in minutes if not seconds at such power levels. A DD motor is always a better choice for most people. Given enough power it will also produce plenty of torque. A dd motor is many times more reliable for the simple fact it's simple with no gears or clutches to fail and it will take much more power than the 500W geared motor.

wesnewell said:

Just do the math. The DD motor is a 12.5Kv motor. At 48V it will have a top speed of 49 mph unloaded speed. Depending on which rpm you get with the geared motor, top unloaded speed will be 16.5mph with the 201 rpm, 21 with the 260 rpm. and 26.8 mph with the 328 rpm motor. The DD motor can withstand 5KW easily for short periods of time. The geared motor would break in minutes if not seconds at such power levels. A DD motor is always a better choice for most people. Given enough power it will also produce plenty of torque. A dd motor is many times more reliable for the simple fact it's simple with no gears or clutches to fail and it will take much more power than the 500W geared motor.

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My only problem with the direct drive motor is that I dont know if the acceleration will be fast enough. Does 1500w 48v DD motors have enough torque ?
On my old 24" bike I have 36v 250w motor with 350w controller and it doesnt ride good on hills but on flat surface I can get up to 36 km/h. Does the 1500w DD motor will be good on hills ?
thank you

White_Ferret said:

motomech said:

The motor you linked is direct drive, are you sure you want to go away from a geared motor w/ lot's of stop and go riding?
The sim. @ Ebikes CA shows the BPM CST(Cassette) just reaching 45 Km under it's own power on a bike w/ the parameters you specified. I didn't ck the climbing performance, but it should be ok for everything but the steepest hills.
Put any $$$ you save by going w/ the BPM vs., say, the MAC, into the battery. Panasonic cells, for example. The controller should be in the 25 to 35 Amp range and the type(sine wave or square wave, which display)would be your next big choice.
You could buy everything from BMS Battery or possibly elifebikes(PWS Power) and consoladate shipping costs.

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So I think I will buy the BPM motor from here: https://bmsbattery.com/ebike-kit/35...-rear-driving-e-bike-hub-motor-ebike-kit.html
What rpm should I choose ?
And I also saw that if I buy 36v RPM motor with 48v battery it will be faster that 48v RPM motor. this is correct ?
thank you

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You could use a 36V rated motor on 48V, but you don't need to because there are lot's of versions of the BPM. According to
Ebike CA sim., a mountain bike w/ 27.5 whl.s and w/ a 48 V batt. and the 48V motor you linked will top out @ 44.5 Kph. It's a 260 rpm @ 36V speed motor vs the BPM CST, which is a 270 rpm @ 36V speed motor, which explains the slight top speed difference.

White_Ferret said:

wesnewell said:

Just do the math. The DD motor is a 12.5Kv motor. At 48V it will have a top speed of 49 mph unloaded speed. Depending on which rpm you get with the geared motor, top unloaded speed will be 16.5mph with the 201 rpm, 21 with the 260 rpm. and 26.8 mph with the 328 rpm motor. The DD motor can withstand 5KW easily for short periods of time. The geared motor would break in minutes if not seconds at such power levels. A DD motor is always a better choice for most people. Given enough power it will also produce plenty of torque. A dd motor is many times more reliable for the simple fact it's simple with no gears or clutches to fail and it will take much more power than the 500W geared motor.

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My only problem with the direct drive motor is that I dont know if the acceleration will be fast enough. Does 1500w 48v DD motors have enough torque ?
On my old 24" bike I have 36v 250w motor with 350w controller and it doesnt ride good on hills but on flat surface I can get up to 36 km/h. Does the 1500w DD motor will be good on hills ?
thank you

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How do people quantify acceleration with ebikes? Is there some kind of standard like the automotive 0-60mph or timed quarter mile or one eighth mile timed runs?

I've been testing my first build that uses a 1000 watt geared hub motor. The most it gets fed is about 1250 watts at around 50v - maybe a bit less. I weigh about 165 lbs. The bike probably weighs close to 70 lbs. It easily goes up moderate 5-6% grade hills at over 20mph (32kph). It has no problem getting up steeper 10-12% grades at probably around 15mph (24 kph). I think I hit some inclines that are even steeper (but shorter) and it still manages to get up them - though it does require some pedal assist. We have an 18% grade about a mile from my house. I suppose I should test the bike out on that. I doubt I get up it without pedal assist. But I wonder how much assist I'll have to add in to the effort.

If you feed a gearless hub motor more wattage, then it will surely accelerate faster and go up hills more easily than my setup. But I have no idea how to quantify that in a way that would help you know if it is fast enough to meet your needs/desires. FWIW, I get through intersections from a stop at about the same speed as the typical car.

The 48v 500w BPM has massive torque compared with a DD motor. For city riding, the 260 rpm one would probably be the best. They normally go about 22 mph (35 km/h). I think BMSB give the code 10 as the 328 rpm, which is actually, 310 rpm, but that's the 36v version. I don't know how the speed codes relate to speed with the 48v versions. I built a bike with one about 3 years ago and ordered the 260 rpm 48v version, and it had a top speed of about 24 mph (38km/h). These motors go really well with the S12S controller and LCD. You need the speed sensor too. If you're not too heavy and you want to pedal, you can save a lot of weight band have a bike that's more like a bicycle than an electric motorcycle by getting one of their batteries with the included 20 amp controller. That'll give you a kit weight of about 8kg. A 1500w DD motor, battery and controller would add about14kg

I think I will go for the geard motor
I checked the max speed of BPM and 1000w DD motor and on flat surface its almost the same (41, 43 km/h) but on hills the BPM is a lot more better.
Also the bpm is a lot more lighter (2.3kg difference).
Whats the diffrent between Bafang and Mxus motor ? Mxus also have good motors ? this is the Musus "BPM" motor: https://www.aliexpress.com/item/48V...32730646447.html?spm=a2g0s.8937460.0.0.H24fc9

how to upload a photo on internet
Thank you

Well, adding 10kg to the gearless motor is going to skew that results a bit isn't it? Would adding 5kg or the 2.3kg be more appropriate? I don't think a hub motor is going to add 10kg is it?

If i run that calculator with just the added 2.3kg you mentioned and not the 10kg, the difference in performance isn't anything close to what I'd call "a lot." Even with a 6% grade the differences are pretty small. For instance, on a 6% grade at full throttle, the geared motor will be 1.8 kph faster. I don't think you can even perceive that difference without looking at your speedo. It would certainly matter in a race, but for most ordinary purposes?

As the inclines get steeper the geared motor's advantage increases. I input your values, adjusted the weight to only 2.3 kg greater for the non-geared, and then ran the simulator so the black curve shows % Grade. The graph to show that the geared motor crosses the line from minor disadvantage in full throttle speed to gaining a minor advantage starting at about a 3% incline. That advantage increases as the grade increases. But there really doesn't seem to be much of a gap between the two until you get to about a 10% grade. But even then, the difference is only about 3 kph. That's about a 15% edge. But lets face it, that's slow on either bike.

So if you have a lot of hills around that have 10% grades and larger, then the performance difference might be noticeable. You'll do a bit less pedaling with a bit less effort going up hills (assuming your inclined to help out). So there is a benefit. But benefit seems pretty marginal to me.

wturber said:

Well, adding 10kg to the gearless motor is going to skew that results a bit isn't it? Would adding 5kg or the 2.3kg be more appropriate? I don't think a hub motor is going to add 10kg is it?

If i run that calculator with just the added 2.3kg you mentioned and not the 10kg, the difference in performance isn't anything close to what I'd call "a lot." Even with a 6% grade the differences are pretty small. For instance, on a 6% grade at full throttle, the geared motor will be 1.8 kph faster. I don't think you can even perceive that difference without looking at your speedo. It would certainly matter in a race, but for most ordinary purposes?

As the inclines get steeper the geared motor's advantage increases. I input your values, adjusted the weight to only 2.3 kg greater for the non-geared, and then ran the simulator so the black curve shows % Grade. The graph to show that the geared motor crosses the line from minor disadvantage in full throttle speed to gaining a minor advantage starting at about a 3% incline. That advantage increases as the grade increases. But there really doesn't seem to be much of a gap between the two until you get to about a 10% grade. But even then, the difference is only about 3 kph. That's about a 15% edge. But lets face it, that's slow on either bike.

So if you have a lot of hills around that have 10% grades and larger, then the performance difference might be noticeable. You'll do a bit less pedaling with a bit less effort going up hills (assuming your inclined to help out). So there is a benefit. But benefit seems pretty marginal to me.

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Sorry its my mistake the 10kg different.
So I understand there is not a lot of difference in the performance. I will ride usualy in the city in 35-40km/h with small hills. What do you think is better for my project ? 1000w DD or 500w geared ? (48v)
I prefer the geared because of its weight but I have no idea which one to choose
Thank you very much

Sent from my ONE A2003 using Tapatalk

Don't let people lead you around, or you will be stuck in this "what should I use" thread forever.
For "in town" riding, the geared motor is the only way to go. For one thing, the DD is as big as a Frisbee, so there goes any stealth that can be built into the Ebike. Also, any unsprung weight, even an once extra, is to be avoided. A couple of years ago, I went from a Q100 mini to an Ezee(same size as the BPM) on my full susp. 2 WD and didn't really feel any difference in handling on the street or lite trail riding. Any larger and I think I would deffinately feel it.
But perhaps the best reason to go w/ geared in town is it's free-wheeling. A lot of my riding is what is called "point and shoot". From the light or stop sign, I'll zip up to speed, enjoying the smooth and effortless acceleration of an elect. motor, and then chop the throttle and coast up to the next lite. Maybe not the most efficient way to get around, but it's fun. DD motor tend to "cog"(elect. interference)and although it can be minimal, it's still there. Lastly, clutch and gear prob.s w/ geared motors are way over-blown, the vast majority of riders here haven't had those problems.
My very first motor was a MXUS geared mini and it was a great motor, but you don't need anything more than the BPM and you certainly don't need to spend any more than you have to on the basics because you will find the little stuff you will need, like better tires, bigger gears on your pedal drive, lights, etc. will add up quickly. In the same vein, you want to get everything from the same vendor to ease to ordering process and to save on shipping costs. Keep your first build as simple as possible while you are learning and you can get fancy later.
So that really means BMS Battery or Elife Bikes(PSW Power), where you can get a whl. assy(motor built w/ whl.), the battery, controller, extra throttles, spoke wrench, torque arms, etc., from one place.
Like I said before, you really need to focus on the type of controller you want to use. The intergrated "bottle battery" w/ 20 A controller, while a little under-rated for the BPM, makes for a less complicated and cleaner install.

Please fill out your profile.

White_Ferret said:

So I understand there is not a lot of difference in the performance. I will ride usualy in the city in 35-40km/h with small hills. What do you think is better for my project ? 1000w DD or 500w geared ? (48v)
I prefer the geared because of its weight but I have no idea which one to choose
Thank you very much

Sent from my ONE A2003 using Tapatalk

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I mostly wanted to make sure you were looking at the simulator with a reasonable perspective. I'm not trying to talk you out of the geared hub. I just hope to help you not make a decision on poor data.

My personal take after reading lots of info is that while geared motors have a torque and efficiency advantage, it isn't as big of an advantage as one might initially think. The reasons bikes today have a gazillion gears (other than marketing) is because human beans typically aren't very powerful, our legs are pretty low RPM motors, and we can't maintain our near best and best power output for very long. So just the right gear ratio can be a big deal. Electric motors, OTOH, have these really nice and relatively flat torque curves.

Personally, I went with a gearless hub motor because I preferred the simplicity, lower noise, and reliability of the non-geared - and I'm commuting, not racing. Personally, I'm thrilled with the acceleration I have. I can keep up with the typical car going through an intersections. That's all I need. I have no desire to pop wheelies and such.

If I were really concerned about high performance, I'd probably just get something like the 3000 watt Cyclone mid-drive and skip hub motors altogether. In fact, I almost did just that. It's easy to get caught up in the idea of higher performance. But given time to reflect, I realized that I wanted something closer to a "regular" biking experience. My main goal was to merely "flatten" the hills where I live so that I don't have to kill myself climbing hills and so I can commute out of town and travel extended distances comfortably. If I can maintain a cruising speed of 20 mph over most terrain with the option to maybe go 25 mph on flat ground if I'm in a hurry, then I'm happy.

Here's a link to a GPS tracking of my commute home last night. The dips are mostly stoplights and/or stop signs. Some of the slower sections are due to lighting or other route conditions that make me a bit more cautious. Note that I can maintain my near 20 mph pace mostly without regard to the inclines. There are, I think, two short steep hills on my route where I actually need to give pedal assist - though I do pedal assist through most of the ride. I think they are approaching 15% grades. Click on the "Map" tab for if you want more detail on speed at specific streets.

http://www.sportstracklive.com/track/detail/wturber/Cycling/Commute-Airpark/ebike-/2351493

If you can do it, I think the best thing would be to seek out people with e-bikes similar to what you are considering and see if they'll let you take them for a test ride. That way you can judge more directly things like how much acceleration is enough.

BTW, if you take the simulator and change the battery from 48v to 52v for just the direct drive hub, you'll see that the direct drive outperforms the geared hub up to about a 10% grade. Just four more volts shifts the performance differential that much. That's how marginal the differences really are in most situations. And look what happens when you feed the direct drive 52 volts and more amps. This leads to the question of which of the two is more likely to survive being fed 1500 watts or more on a regular basis? My guess is that it would be the direct drive.

wturber said:

Well, adding 10kg to the gearless motor is going to skew that results a bit isn't it? Would adding 5kg or the 2.3kg be more appropriate? I don't think a hub motor is going to add 10kg is it?

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You have to allow for the bigger battery too. You need 35 amps to get those motors going, so you need a battery capable of giving that, and then your consumption will be higher, so you need more capacity for that too.

I decided to buy the BPM motor. I saw that BMSBATTERY have 201, 260, 328 rpm motors
I need the 328 option right ? it will give me max speed of 42 km/h
https://bmsbattery.com/ebike-kit/35...-rear-driving-e-bike-hub-motor-ebike-kit.html

wturber said:

Here's a link to a GPS tracking of my commute home last night. The dips are mostly stoplights and/or stop signs. Some of the slower sections are due to lighting or other route conditions that make me a bit more cautious. Note that I can maintain my near 20 mph pace mostly without regard to the inclines. There are, I think, two short steep hills on my route where I actually need to give pedal assist - though I do pedal assist through most of the ride. I think they are approaching 15% grades. Click on the "Map" tab for if you want more detail on speed at specific streets.

http://www.sportstracklive.com/track/detail/wturber/Cycling/Commute-Airpark/ebike-/2351493

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How much does your bike weigh? can we see a photo of it?

d8veh said:

wturber said:

Here's a link to a GPS tracking of my commute home last night. The dips are mostly stoplights and/or stop signs. Some of the slower sections are due to lighting or other route conditions that make me a bit more cautious. Note that I can maintain my near 20 mph pace mostly without regard to the inclines. There are, I think, two short steep hills on my route where I actually need to give pedal assist - though I do pedal assist through most of the ride. I think they are approaching 15% grades. Click on the "Map" tab for if you want more detail on speed at specific streets.

http://www.sportstracklive.com/track/detail/wturber/Cycling/Commute-Airpark/ebike-/2351493

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How much does your bike weigh? can we see a photo of it?

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Funny you ask. I just weighed it last night. It's 66lbs with the battery pack. I weigh about 165 lbs. I might have 10 lbs of stuff in my backpack while commuting. So let's call it 240 lbs rolling on a commute.

Here's an early photo sans lights and water bottle. It's pretty messy right now. Everything is currently in a trial configuration. I plan on tidying things up and coming up with a better battery case in the next few weeks as well as camouflaging the booster somehow.



The battery is currently about 12 pounds of five 36v (10s x 2p 18650s) packs that are charged to 41v for about 20 aH or about 750 wH capacity.

This describes the booster and my thoughts behind using it. The topic needs updating though. Riding tests show that the booster is delivering right around 1200 watts at its peak and that my watt-hours per mile estimates are probably way off (too high).

https://endless-sphere.com/forums/viewtopic.php?f=2&t=90369&p=1318604#p1318604

Personally, I went with a gearless hub motor because I preferred the simplicity, lower noise, and reliability of the non-geared

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I'm not contradicting anyone, except that my MAC 12T (similar to this geared hub motor in question, though maybe the next slower wind) is super-quiet.

I read a lot of talk about geared motor noise. I made plenty of mistakes in my first build, but the thing I think I was most pleased or relieved about was how quiet my motor was. (And I agree now, a first build should be seen more as an experiment--one of my biggest lessons--but isn't all of life an experiment.) I watched Neptronix's MAC videos with close attention for sound, and now think his camera/mic was either closer to the motor than I realized, or that the recording is somehow compressing the sound to a degree where it gives a wrong impression.

I just demonstrated my bike to 2 masculine adult males who knew nothing about ebikes. They both own Harleys. One owns a backhoe type tractor. The other owns a 4-wheeler. Starting right beside them, going away, then coming back, neither could hear my motor noise. In truth, they could, but they did not discern it as motor noise until I helped point it out. They thought it was tire noise (I was on grass/gravel), and the motor noise is about the same as the tire noise--that is, 'almost nothing'. And I don't even have a sine wave controller. I also own a very cheapo mass-produced 500-750W DD ebike, and that's extremely quiet too, but it also makes noise--again, nothing significant. This is coming from a person who is mostly drawn to ebikes for the quiet.

These 2 men also could not figure out where the motor was. They both gave up. They had a hard time believing it even after I pointed it out, especially after seeing the performance. My mac is about the diameter of my disk brake. They just saw a bike hub. Having all black in there helps. To our eyes, that seems laughable now--but they are savvier than the average person who'll be riding on the road. They were blown away. And although I don't base self-worth on others' opinions, I do see them as more 'manly' men than myself, and was curious and admittedl a little gratified to see how these 2 Harley owners would react (and did react) to this piece of kit. They knew my top speed and I think they, like me, would be left wanting more like I was.

If it had been a DD, they would've easily been able to figure it out. A female neighbor also was able to figure out that my cheapo DD ebike was powered, and proactively asked me if it was, despite not seeing me ride it (though not a great leap of logic).

I think people tend to think that what they have, is the best thing. Why? Because ALLLLLL eeeebiiiikes are sooo much freakin' fun! Lol!

Even if I had built the exact right bike for what I (thought I) wanted at the time (which I actually did, somehow), I think building the perfect ebike the first time is impossible almost, because... my priorities changed (which I wasn't expecting). I thought I'd never want to go a faster than low 20s MPH (less than 40Km/h). I wasn't expecting that I'd become a better rider, and be less afraid of the speed. I wasn't anticipating wanting to ride on paved open roads more. I wasn't anticipating not having access to as much off-road areas as I thought I'd have.

Geared reliability/maintenance (outside of motor overheating) itself is not a concern; Ozzz's (hope I got the nick right) great journey on a mac 12T fatbike from Canada to Mexico on that huge bike trail through the Rockies, proved that. If you're gonna put on thousands of miles in just a few years, needing it for real-life transport, yeah maybe a concern, but replacing the clutch/gears is also not that big of a deal at that point. I think if you're a commuter, that's where you gotta get real serious. Especially WATER (especially controller, wires, bearings). BUT, I think if you're already a bike commuter, you'll have a much better idea of what you need/want (much more challenging workload/importance).

The problem for me with a geared is being afraid of wantonly abusing it, even if briefly/accidentally. Under certain watts, this is not a huge concern. Also I understand Cycle Analyst and also I believe programmable controllers can be programmed for ramping accelleration, so again, there are solutions. DD can be wantonly abused briefly with little concern. I saw CA readings of DD riders going into the thousands of watts, frequently maxing out whatever their controller could do, and just to get started. 2500, 5000W (Neptronix Leafbike videos). I remember early videos of Neptronix on [abusing] his mac, going up those horrendous long, sloping mountainous roads of Utah terrain. He melted the 1st gen set of gears, but replaced them with 2nd gen, and was somehow fine after that, and few will treat that motor like he did.

I am still intrigued with DD, but I doubt I could pick up my bike w/a strong DD. Not that that's a dealbreaker. But if you commute and have to carry your bike somewhere, consider that. I can w/my current setup, but it's not fun.

I love the stealth and quiet. Cows don't hear me coming and I frequently surprise aninmals (dogs are more sight-aware, and go apoplectic over my bike, if they see me, but often I sneak up on them too). Some people don't care. It's all priorities. People see me fake-pedal, and they don't even look at me anymore. I'm just a bike now, not interested--even being a fatbike somehow. As someone who unintentionally attracted attention his whole life, I love that.

I didn't want a mid-drive because I PERSONALLY didn't want to be shifting all the time, and having throttle basically be a 2-handed affair. Plus I lacked the skill or learning curve motivation to install it. For many though, it's perfect, especially for riders with good knees.

There are tons of downsides to a hub motor too. Torque arms, fearing flats, curse-worthy chore of taking your rear wheel off, the necessity of bringing a surprisingly heavy toolkit with me (including a big old 21mm wrench--ugh!), worried about spinning dropouts, breaking spokes.. tons of stuff. But, in the end, my only regret ended up being that I wished I could go faster. Which might be solved with higher voltage (reducing amperage to keep the same watts) vs a new motor w/faster wind.

The latest thing I've been thinking about (kinda forced into it), is the possibility of slow/'torque' winds combined with higher voltages. To get both the power and the speed. If I limit the amps to equal same watts as before, I'm not sure if this is bad or even good/better for a MAC 12T. Maybe I should start my own thread on that, but feel free to reply, as I think that strategy is germaine to the OP. (or PM.) And I'm not all-knowing, but if I were going to do direct drive, I'd be looking at that kind of formula, using voltage as a gauge of speed. That (plus oil cooling) is basically how an ES member (sorry, I forge his name) won 1st place for 2-wheeled EBikes at Pike's Peak [websearch it]. I think the trend on our forum will be to voltages above 48V, and you can see this already on battery vendors like LunaCycle. I don't consider myself an expert, but I am now experienced.

There is tons of good advice on here, plus some well-intended bad advice, which I've probably been guilty of too. The latter I think mostly coming from (and this is not aimed at any individual, honest):
-People telling you what's the best for THEM, not you
-People with agendas/unsuspected loyalties (more in being inappropriately defending of a product/vendor/type/____ when someone experiences or raises a legitimate issue)
-People commenting on stuff they haven't used, or just being mistaken or remembering something incorrectly
-Stuff that is true, but should not be a big issue to you (hard to know)

The truth is, you'll probably change your arrangement later, which can make the hobby seem like a small money pit at some times (compared to a used motorcycle or $700-1200 used dirtbike for instance, where you mostly just do oil, air, and fuel). I say: go with what your heart wants! The only person who has to be happy with it is you! You'll make mistakes, but in the end it'll be okay. Hope that helps someone.

SprocketLocket said:

The truth is, you'll probably change your arrangement later, which can make the hobby seem like a small money pit at some times (compared to a used motorcycle or $700-1200 used dirtbike for instance, where you mostly just do oil, air, and fuel). I say: go with what your heart wants! The only person who has to be happy with it is you! You'll make mistakes, but in the end it'll be okay. Hope that helps someone.

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Your post makes a lot of good points and provides a nice perspective. The situation with ebikes reminds me a lot about the situation with mirrorless and digital SLR cameras. It is generally kinda hard to make a truly bad choice. There's no need to wring ones hands "worrying" about the matter. So I agree. Do some basic checking so you aren't making any obvious gross errors - then just do what feels right. These things are all compromises. There is no perfection.

wturber said:

Funny you ask. I just weighed it last night. It's 66lbs with the battery pack. I weigh about 165 lbs. I might have 10 lbs of stuff in my backpack while commuting. So let's call it 240 lbs rolling on a commute.

Here's an early photo sans lights and water bottle. It's pretty messy right now. Everything is currently in a trial configuration. I plan on tidying things up and coming up with a better battery case in the next few weeks as well as camouflaging the booster somehow.

The battery is currently about 12 pounds of five 36v (10s x 2p 18650s) packs that are charged to 41v for about 20 aH or about 750 wH capacity.

Click to expand...

Here's my bike. It easily averages 20 mph with my 85 kg on board. It weighs 21 kg and is nicely balanced, so has nice handling. It also has air suspension for ultimate comfort:

Whats about MAC 10T geard motor ? Is it better than the Bafang bpm motor ?

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I can't tell you which is better, I'll leave that to others, but owning a 12T, I agree with the 10T wind (or equivalent in Bafang). 12T has crazy [strike]almost[/strike] actually scary torque when running at a healthy dose of wattage. It was actually more than I expected. Pulls like a freakin' mule at low speeds. It's like a Porsche stuck in 2nd gear. But then left wanting more once you get used to riding faster. With these tall fat tires (like 29-inch equivalent), I max out at 23-24mph at 50V. So, the question: higher voltage, or bite the bullet and get a 10T? Right now I could configure 72V with no extra cost than a new controller. Controllers are a lot cheaper than new motors. Maybe at higher voltages, you could get the best of both worlds, mistake turns into dumb luck? Kicking myself I got the 3077 (60V limit) vs the 4110 (90V limit!, and still 48V-compatible!). Yeah 3077 is more efficient, so what, my controller hardly even gets perceptibly warm (ventilated). 4110 is so much more flexible, argh. "What was I thinking" moment. (One of those mistakes I referenced.) Learn.. from.. me.. aauugggh...

BTW that SportrTrackLive thing is pretty nifty..

I recieved the BPM from bmsbattery, I ordered the 48v 500w 328rpm rear version
Now I need to order a 650b 36h rim, I found this rim: https://lunacycle.com/alex-tubeless-ready-rim-dp21-27-5/ and after I will recieved it and measure I will order the right spokes. What spokes thickness should I buy ? 2.0/2.3/2.6mm ? the motor spoke holes are 3.2mm.
I also need to choose a controller. I can buy this sine wave controller https://bmsbattery.com/ebike-kit/72...imulation-sine-wave-controller-ebike-kit.html, do you think that 1000w is too much to this motor ? they also have 500w version.
Thank you

I always use 14g (2.0) spokes. If you want a to spend a bit more 13g/14g butted spokes might be better. definitely don't use anything thicker than 13g.

20A at 48v is normally more than enough for an electric bicycle. I'm 82kg and find that 14A is enough for me and our very steep hills. If you want something more like an electric motorbike, get the S12S. The controller you linked is way too much for a bicycle, and at 40A, you'd need a high discharge rate or very big battery.

Whichever one you get, you need an LCD and a wheel-speed sensor. You should get a PAS too.

At risk of re opening a can of worms,, comparing the 500w rated geared motor with a 1500w rated DD is like comparing a ford focus motor with a one ton trucks 450 cubic inch V8.

You betcha the V8 can accelerate fast, and it would be crazy fast if you crammed it into a focus.

But here is the real difference, if you power up that DD nicely, meaning 2000 watts or more, it WILL blast off the line much faster than the geared motor, that you feed approximately 1000w. Twice the power, after all, or if you wish, 4x the power.

But,,, it will also eat power at 2x the rate, till you reach the cruise speed you want of 45 kph. And it will require a much stronger battery in the max amps rate. Big motor needs the big gas tank.

Choose which one you want, decent acceleration close to same as the cars for the first 50 feet, and less need for a very expensive high amps rate battery. Or, you want to spend more on the battery, and wheelie across that intersection.

Both bikes will be fun to ride, but the very fast, very powerful one will be more fun. So ask yourself if you want to get around efficient, or have fun at any cost.