Noobie planning an Electric bike with >30 mph

macribs

macribs

10 MW
Joined
Jul 22, 2014
Messages
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Hello to you all. I am first time poster here at ES. I've been hanging here for a couple of weeks now to gather info from all your experiences.

I am about to start building a ebike.
I got a 15 km commute each way for work. But can charge at work if needed.
I am a heavy rider, approx 110 kilo, 17.3 stones or 250 lbs. My place is littered with steep hills and that goes for the road to work as well.

So I am going to make some adjustment to the very first post in this thread, because as I collected info things have become a little more clear for me and I now have a better understanding of what I will needing to accomplish my goals for an electric bike.




My goals for this build is as follow:

1: Range must be > 15 km. Everything above that is a bonus.

2: Top speed preferable >30 mph. If I reach 40 mph I will be even more happy.

3: A combination of motor and batteries that will let me do some steep hill climbing on my commute as well as giving me > 30 mph. .

4: Rim, hub and spoke combination that will handle my rather heavy body without braking down commuting to work on paved roads.

5: As an added feature I would like to be able to joy ride the bike hooligan style if I feel the need. That means durable and well build.

6: I would prefer to loose the derailure and the cassette and use a single speed setup and enclose both sprocket and chain.


If have as of today no full clue as to how I will be able to meet these criteria's. That means I am not sure what motor to choose, how to modify said motor to avoid over heating and I also green as to which is the best controller to choose. Same goes for the batteries. So I need help guiding me to make good decisions on what hardware to get in order to be able to make an electric bike that meets my need.



I got to say I am inspired by a certain bike at kickstarter, and that I would be so excited if I could do a similar thing for my electric bike. Have the whole chain and sprockets enclosed. Not only will it look the part, but I will never have to worry about oily pants etc.

I mean look at this beauty isn't she nice?

cf3e5a906aa3c16aa00c6b6abf319350_large.png
 
Welcome to the forum.

The Nuseti does look like a great bike. But it's not an enclosed belt, it uses a chain. Belts don't come apart, so they can only be used on frames with a removable seat stay or chain stay.

The main draw back of a belt is you give up ~5% efficiency over a chain by using one. And you give up another 5-10% efficacy by going with an internal transmission like the Nuvinci.

1. Nope. Most all crank transmissions are sold only to frame manufacturers, and aren't available to general public.
2. Sure, you can run a front motor with a mid drive, or rear, or all 3 together.
3. Nope. Gates makes the only good belt drive, but they aren't really compatible with mid drives or most bike frames. And giving up efficiency means they have no benefit for an ebike.
4. Doesn't exist. Yet. Could be built, but other than weight savings, it would be inferior to a good chain drive in almost every way.
5. Sure. However, it doesn't save battery. It takes roughly 350 watts to do 30kph. It doesn't matter how you make that 350 watts. Running 2 motors, each will consume 175 watts to make that 350 watt total. If you shut one motor off but keep moving at 30kph, the other motor will have to make the full 350 watts, so no power savings.
6. Yes. Each brushless motor needs it's own controller. You can use 1 battery and 1 throttle, though. However, the battery needs to be able to handle the output needs of 2 motors.
7. Yes, welding on aluminum anneals it. after welding, it must be heat treated to regain it's strength. that involves stripping the paint and baking it in a kiln. An alternative is to build so heavy duty that the new parts are as strong as the old even without the heat treating. however, that often means the frame will be heavier than an steel frame of a similar design would have been. Steel doesn't lose strength when welded.
 
Thx Drunkskunk. So a reply to your answers:

1: OK so then I will drop that crank transmission.
2:OK so any configuration will do well together even using 3 motors. :D Guess Crank motor and front hub is the way to go then.
3: So belt drive is just a waste of energy and efficiency. Guess that means using chain.
4: Well if I am stuck with chain at least I will loose the derailleur and the cassette. And then I should be able to build chain and sprockets enclosed.
5: Did not know that, I thought using 1 out of 2 motors would save battery. Cos now that you explained it that makes sense. Well that makes for easier build then.
6: 2 controllers means twice the cabling and more clutter. I saw one of the forum member that build controller for sale, you think he would build a box containing two controllers?
7: Yeah was afraid of that. But the good thing is that baking the frame will hardening the frame.


Well then. If I drop the drive belt I can then use internal gear either Nuvinci or Shimano Alfine. Some efficiency loss is acceptable due to a cleaner look. And if I get the whole chain and sprocket enclosed I will not have to worry about dirty pants, fold up right pant leg, waring long tube socks or any of that crap.

There are so many motors, producers and price ranges that it is hard to know what is a good motor and what is not. I read about Pie, golden motor, Hi power, GNG, Cyclone and what not. Let's say I will go for a total of 3.000 Watt of power.


5 more questions for now:

1: What would be the best 1500 watt hub motor to put in my front wheel?

2: Do any of the hub motors come with enclosed controllers?

3: Of all the hub motors I have found only one that have 1.500 watt. The OZ from Aussie. Is this a durable motor that is worth buying or is it a cheap "home made" motor of a used "start engine" from a scrap yard?

4: I've read about motors overheating. When fitting a crank motor I could make a one off heat sink with a large outer area. Will that air cooling prolong the lifespan of motor?

5: I read about geared motors and gearless motors. What are the difference and which is the better choice? Brush less motor is a given..
 
Ok so I did some more reading on this great forum and it seems I've been going about this all wrong.
From what I read it seems geared hubs are the way to go because the motor spins faster then the wheels. And it seems that those geared hub motors when oil-cooled will withstand almost any and all abuse, as well as deliver far more power then their spec sheets suggest. Also I see people implement temp controllers so they can manage the heat from racking the motors. So rather then spending extra money on crank motor I am now leaning towards a plain and simple 2WD using geared motors and modify those motors with oil cooling. But if I somehow can find a reliable 3.000 Watt geared brushless motor I might as well go for rear wheel drive only. Less weight and less stress on the fork.

What do you think is the best option, push all power for high speed from a single motor or let 2 motors work together letting them both work little easier and therby prolong the life span of motors?

If I then use some special epoxy from 3M it also looks like I might not need to do any welding at all according to Keyne's DH Comp Build thread. I believe that those torque arms/drop outs where actually glued to the frame rather then welded, is that correct?

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So if I still am a little hooked on the whole easy to maintain thing and clean look I guess I can do a one-gear conversion using sprockets/gearing that will be like a little on the heavy side, like in a low gear/small sprocket on the cassette? That way I will still be able to box in the chain and the sprockets.

Are that motor used by Keyne still rated as one of the toughest motors around? Seems the thread is 3 years old so lot of things could have been out since then.
Did any of the motor manufacturers pick up on the idea of oil-cooling the hub motor?
 
I can only offer you a small CVT that can tuck in.

http://www.aliexpress.com/item/High-Quality-HUASHENG-Brand-49cc-2-stroke-Engine-or-37cc-4-stroke-Engine-Gearbox/1314048097.html
 
The Nuvinci N360 will slip if you put too much torque through it. It'll just about be OK with a 750w Bafang crank drive if you're careful in the lower gears. The GNG at 36v and 25 amps is about the limit. The 60v GNG will probably rip it to shreds.
 
OK, so I drop the plans for nuvinci or anything else like that.

For the sake of prolonged life for the motor will I benefit from using 2 motors and make a 2WD or should I just go the obvious route with single motor rear wheel drive?


How is the quality of the magic pie 3 hub motor? They have internal controllers. Will it be possible to use a liquid cooling system with a radiator and a fan if I choose the magic pie 3? If I use non conductive fluid like 3M Novac or similiar product?

What about the controllers in the Magic Pie 3? Are they good and reliable or should one opt for a Lyen controller?

I've read that even the Lyen controller gets very hot, will fluid like 3M Novac be sufficient for cooling the Lyen controller? I think I closed system with pump and radiator will do the trick and the Novac should not lead to corrosion, static or in any other way play faul with the Lyen.
 
1. None. Unless you mean 1500w peak. That's about all the power you should put into a front fork. Most motors are rated at nominal power, not peak power.
In that case, "best" is subjective. Best at what? if there was such thing as a "best at everything" motor, there wouldn't be so many choices.
2. Yes. there are a few, although the most versatile is the Magic Pie. However, having a device that is sensitive to heat locked up inside a device that has trouble enough managing it's heat is generally a request for failure, especially at higher power levels. The magic pie works fine if you conform to lower power levels.
3. That's not a hub motor, that's a mid drive. Very likely they mean 1500 watts peak, and that looks like a standard 500w motor. Most motors are rated at nominal power, not peak power.
And I wouldn't call that a good kit, now. 6 or 8 years ago that would have been rather innovative, using brackets that hook to both sides of the BB. But seriously... the chain guard has rust on it in their advertising pics.. And a water hose clamp... That thing is either: (A) A chaindrive cleverly disguised as a pile of scrap, or (B) An actual pile of scrap.
4. You could, and yes, probably. But there are so many variables and unknowns about which motor, what conditions, and the design and implementation of the heat sink that any speculation on how effective it might be is pointless at this point. It might be the greatest thing ever, or it might only give a 0.0000001% increase in the cooling efficiency of the motor.
5. Gearless Direct drives for the Win! Except when they aren't. then geared motors for the Win! In reality, Both, and neither.
Questions like this are like asking what is better, Ford or Chevy. Coke or Pepsi. Blondes or Redheads. Blue eyes or Green. Sun Rises or Sun Sets. Going back to answer #1, if one was clearly better, the other wouldn't still be around.

The motor Keyne started out with was one of the most powerful known to Ebikes, the 5305. It's about the 3rd most powerful ever built for a bicycle. The motor he ended up with, the MAC, is way down the list in power, peaking at around 1500 watts. But power isn't everything. he picked the motor that best suited his needs.

It might help us to give better answers if we knew what you plan to use your bike for. Generaly we need to know (a) what an ebike must be able to do for you, such as it must be able to climb the 5KM mountian road, ot it must be able to get me 10KM to work with >99% reliability over flat terrain and bike paths, and then (B) we also need to know your wants, like 40kph top speeds, ability to haul 25kg of cargo, and be silent enough to sneak up on game animals.

Sometimes its easy to recommend something that meets a persons needs and wants. sometimes their needs can be met, but their wants can't be, or can't be reasonably. And sometimes people come here with needs that just can't be met by an ebike, and we have to reluctantly tell them to go get a motorbike, or a car, or for one person, a very large truck.


At this point, it might be of more help to you if you told us what your expectations of an ebike are.
 
macribs said:
I am about to start building a ebike.
I got a 15 km commute each way for work. But can charge at work if needed.
I am a heavy rider, approx 110 kilo, 17.3 stones or 250 lbs. My place is littered with steep hills and that goes for the road to work as well.
Click to expand...

Mid drive motor running via chain to your CVT nuvinci @500-750watts (any higher power could strip your Nuvinci). This forum has ohso many Ebike options it can be overwhelming & exciting. Don't go superfancy & over complicated when your first learning, it puts a lot of obstacles in the way before you could even turn on & ride. You need to crawl before you walk, as they say. Next thing you know, your ready to take the big plunge.

Why not buy an off the shelf bicycle with Nuvinci drive, and further modify it via a mid drive? Easy peasy and ready to ride within a month or less.
 
Drunkskunk said:
1. None. Unless you mean 1500w peak. That's about all the power you should put into a front fork. Most motors are rated at nominal power, not peak power.
In that case, "best" is subjective. Best at what? if there was such thing as a "best at everything" motor, there wouldn't be so many choices.
2. Yes. there are a few, although the most versatile is the Magic Pie. However, having a device that is sensitive to heat locked up inside a device that has trouble enough managing it's heat is generally a request for failure, especially at higher power levels. The magic pie works fine if you conform to lower power levels.
3. That's not a hub motor, that's a mid drive. Very likely they mean 1500 watts peak, and that looks like a standard 500w motor. Most motors are rated at nominal power, not peak power.
And I wouldn't call that a good kit, now. 6 or 8 years ago that would have been rather innovative, using brackets that hook to both sides of the BB. But seriously... the chain guard has rust on it in their advertising pics.. And a water hose clamp... That thing is either: (A) A chaindrive cleverly disguised as a pile of scrap, or (B) An actual pile of scrap.
4. You could, and yes, probably. But there are so many variables and unknowns about which motor, what conditions, and the design and implementation of the heat sink that any speculation on how effective it might be is pointless at this point. It might be the greatest thing ever, or it might only give a 0.0000001% increase in the cooling efficiency of the motor.
5. Gearless Direct drives for the Win! Except when they aren't. then geared motors for the Win! In reality, Both, and neither.
Questions like this are like asking what is better, Ford or Chevy. Coke or Pepsi. Blondes or Redheads. Blue eyes or Green. Sun Rises or Sun Sets. Going back to answer #1, if one was clearly better, the other wouldn't still be around.

The motor Keyne started out with was one of the most powerful known to Ebikes, the 5305. It's about the 3rd most powerful ever built for a bicycle. The motor he ended up with, the MAC, is way down the list in power, peaking at around 1500 watts. But power isn't everything. he picked the motor that best suited his needs.

It might help us to give better answers if we knew what you plan to use your bike for. Generaly we need to know (a) what an ebike must be able to do for you, such as it must be able to climb the 5KM mountian road, ot it must be able to get me 10KM to work with >99% reliability over flat terrain and bike paths, and then (B) we also need to know your wants, like 40kph top speeds, ability to haul 25kg of cargo, and be silent enough to sneak up on game animals.

Sometimes its easy to recommend something that meets a persons needs and wants. sometimes their needs can be met, but their wants can't be, or can't be reasonably. And sometimes people come here with needs that just can't be met by an ebike, and we have to reluctantly tell them to go get a motorbike, or a car, or for one person, a very large truck.


At this point, it might be of more help to you if you told us what your expectations of an ebike are.
Click to expand...


Ok lets start at the bottom of your reply. With what I feel the bike must be able to handle.

A: A commute to work and back. 15 km each way. I can charge at work. So minimum of 15 km range. And preferable at OK speed > 30 mph. If I can go 40 mph that is just a bonus. There are some steep hills both right around my house but also towards work it is much up and down. So I would be happy if the motor would handle hills as well as OK speed. So far the BMC v4 seems to be able to do that because it is a geared hub motor. And according to vaorius articles on electricbikes.com it seems like the BMC v4 is well cooled with oil or even radiator setup. With heat sensors one should be able to avoid overheating.

B: Dead silence is not something to strive for, but one would like the bike to be a quiet as possible. I do not need to sneak up on a sleeping polar bear, I rather out run it with greater speed :D I aim for 30 mph speed but I will be more then happy if there is some extra grunt. And I do think I will do some light cargo hauling. But that is not gonna be a long haul, nor will it be very heavy. 3-4 bags of grocery or a couple of kids in the trailer to make an ice cream run. But that will not be more then once or twice a month so I do not think I should put too much attention to that part.

1: So because the forks can't take the torque of strong motors will that mean I should just go for rear wheel drive and get all power from 1 motor?

2: Seems Lyen controllers are the way to go so I do not worry anymore about using default controller.

3: Yeah kind of what I thought when I looked at the webpage. I will step away from crank motor due to increased price and complexity.

4: OK. No extra air cooling cos air cooling sucks, basically. Could I top of ie the BMC v4 with transmission oil and be golden? Or should I go for a more complex liquid cooled system with a radiator, pump and fans? Here I would like to stress that I would prefer to choose the route that ensures increased longevity for motor and no melting break downs cos of over heating. That way I can also take out more power from the motor without the constant fear of burning up the wiring and melting the inside of the hub.

5: OK so lets see about the pro's and con's for both geared and direct drive hub motors:
Geared pro's:
  • Let me get OK top speed while still manage to climb steep hills on a daily commute.
  • Smaller and lighter then DD hub drive. Less unsprung weight.

Geared hubs Con's:

  • Higher priced the DD motors.
  • Makes more noise then DD motors.
  • More prone to failure due to more complex build.

As I wrote the list it feels like I already have settled for the geared option. I will need to read up on this issue before completing it for the DD hub motor as well.
 
melodious said:
macribs said:
I am about to start building a ebike.
I got a 15 km commute each way for work. But can charge at work if needed.
I am a heavy rider, approx 110 kilo, 17.3 stones or 250 lbs. My place is littered with steep hills and that goes for the road to work as well.
Click to expand...

Mid drive motor running via chain to your CVT nuvinci @500-750watts (any higher power could strip your Nuvinci). This forum has ohso many Ebike options it can be overwhelming & exciting. Don't go superfancy & over complicated when your first learning, it puts a lot of obstacles in the way before you could even turn on & ride. You need to crawl before you walk, as they say. Next thing you know, your ready to take the big plunge.

Why not buy an off the shelf bicycle with Nuvinci drive, and further modify it via a mid drive? Easy peasy and ready to ride within a month or less.
Click to expand...


OK, after reading up I have decided to skip the nuvinci and rather go for hub motors. As for an easy build I am not sure that is even possible as things are today. Seems all motors will need some sort of extra cooling. Either submerged in transmission fluid inside the hub or water cooling setup with pumps, radiators and fans. I noticed that even some sort of temperature controller inside the hub is a must to avoid overheating. So while at it on could also monitor the controller as well.

Main goal and most important of this build is to make a durable and tough setup that can take abuse without break downs. If that means going into pc-overclocking-mode and set up a water cooling system I will do that rather then struggle with burned motors.
 
OK, what is this hype about 29'ers? Does that apply to electric mtb's as well?
Will a 29" set of wheels make it easier to maintain good speed on a daily commute over a standard 26" bike?
The rolling resistance is lower on the 29", but is it low enough to be noticeable for an e-bike also?
 
I think using 26-inch wheels will give you a better selection of fat tires right now. Plus, for 29'r wheels, you'd have to lace the hubs to rims yourself (doable, but a PITA).

If you have the budget for it, I think your requirements might be met by two MACs (geared hubs from em3ev.com). If you track the temps and auto-limit the amps with a Cycle Analyst V3, I don't think you'll need oil-cooling. Of course if the log shows that the hubs had to have their amps limited too often to keep running, you could add oil-cooling at that time. One throttle, one battery pack, two controllers, and two geared hubs.

Read these articles on 2WD's:

http://www.electricbike.com/custom-build-gallery-duty-cycle-awd/
http://www.electricbike.com/custom-build-gallery-teklektiks-dual-motor-yuba-mundo/
http://www.electricbike.com/custom-build-gallery-zlatkos-mental-manno/
 
Thx spinningmagnets. I will read up on those links.
So much information on this board. A shame I didn't find this treasure 2-3 years ago when I first started to consider an e-bike.

Seems like a good setup on The Duty Cycle AWD.
What I can not comprehend is how he can get that speed and range while not putting to much stress on the fork?
It was said earlier in this thread max 500 watt on the front wheel. Is the Duty Cycle AWD running a smaller output from the front motor?
Or are both motors set up so they do not run a maximum power?

Not being an engineer or a mechanic for me it seems that when opting for 2WD both motors must have the same output power?
 
spinningmagnets said:
I think using 26-inch wheels will give you a better selection of fat tires right now. Plus, for 29'r wheels, you'd have to lace the hubs to rims yourself (doable, but a PITA).

If you have the budget for it, I think your requirements might be met by two MACs (geared hubs from em3ev.com). If you track the temps and auto-limit the amps with a Cycle Analyst V3, I don't think you'll need oil-cooling. Of course if the log shows that the hubs had to have their amps limited too often to keep running, you could add oil-cooling at that time. One throttle, one battery pack, two controllers, and two geared hubs.

Read these articles on 2WD's:

http://www.electricbike.com/custom-build-gallery-duty-cycle-awd/
http://www.electricbike.com/custom-build-gallery-teklektiks-dual-motor-yuba-mundo/
http://www.electricbike.com/custom-build-gallery-zlatkos-mental-manno/
Click to expand...


Are you the guy behind that website, electricbike.com? I read the full forum thread for the duty cycle awd and got that impression.
Great work with that site, it holds valuable information, and it looks good too. Nicely done. Bet you have a blast testing all those great bikes :D
 
There have been several guest writers (dogman, kingfish, etc), and most of the articles were written by the site owner, Eric. This last year Eric has been pretty busy, and the more I wrote, the more he was able to spend time on other things, so...I've written most of the recent articles. I've been especially pleased to be able to write features about the custom bikes from the endless-sphere archives.

The hot rods seem to get the most clicks, but I am very glad we could do a feature on Miles' eMoulton, Teklektiks 2WD Yuba, etc (all the custom build features are wonderful, but they shouldn't all be monster Cromotors)
 
After reading up on that 2WD Duty Cycle it does seems doable to have 2WD, OK speed and plenty of torque for acceleration and steep hills.
Is there money to be saved by going the same route for batteries as he did, buying "Tesla" (Panasonic NCR18650PD) batteries and put them together yourself? As these are the same batteries as Tesla uses I guess that is a seal of approval from Mr Tesla, Elon Musk so they should be good.

Are there any downside to use Li Io over LiFePo4 batteries? Like which one has the best power to weight ratio?

It seems to be consensus here at ES that Lyen controllers is among the best controllers. Is that still the case? Many post I've read is like 3 years old....
As I try to get an understanding of the controllers I read somewhere that more FET's would make for a cooler running controller.
Are there any drawbacks to choose a controller with 18-24 FET's over a say 12 FET controller? Space maybe? As I am more and more set on running a 2WD I will need 2 controllers. Should I choose based on the most FET I can fit to the bike, or what makes one controller better then the others? Take the selection over at Lyen.com. There are like 11 different controllers to choose from. What makes for the best controller?


Controllers from Lyen:
  • 6 FET 4110 Mini Monster Programmable Controller LYEN Edition $79
  • 6 FET 4110 Sensorless Mini Monster Controller LYEN Edition $89
  • 9 FET 72V Infineon Brushless Controller (LYEN's Edition) $89
  • 12 FET 4110 MOSFET Extreme Modder Controller LYEN Edition $129
  • 12 FET 4110 MOSFET MK2 sensorless Controller LYEN Edition $149
  • 12 FET 84-132V High Voltage Racing Controller - LYEN $199
  • 18 FET Low RDS MOSFET Overclocker Ready LYEN Controller $199
  • 18 FET Low RDS MOSFET Overclocker Ready Sensorless LYEN Controller $209
  • 18 FET 4115 MOSFET 84-132V Real Highway Speed Controller $259
  • 24 FET 10000Watts Muscular High Current LYEN Controller $299
  • 24 FET 4115 MOSFET 84-132V Freeway Speed Controller $349

How can one possible decide which controller to pick when having no clue what separates one from the other?
It starts to feel like one must have a master or a Phd in electrical engineering plus a bachelor in mechanics to be able to build an e-bike. :D
I had no idea I had to jump trough all this in order to make sane choices for what parts to use. I guess I was picturing it more like picking a battery from one website, a frame from another and it would just magical fit together. :D :D :D

Sadly I was very much wrong. :cry:

Is there any of the forum members that build and sell electric bikes? Or maybe solder stacks of 18650 together and stack it in a custom box to fit your frame? Or what about modded motors? Anyone here who is selling modded geared brushless hub motors to prevent over heating? There are so many skilled people here, so I am sure some must have seen a business opportunity at selling modified parts to noobies like me.
 
Lyen's controllers are good, but they are partially modified Infineon controllers. His target clients are those who want to modify a controller for ballz out insane performance. They work fine, but the idea is to buy one of his and finish modifying it your self to get it as close to the edge of awesome/explosion as you can.

If you're not dragging around a 50lbs pair of brass babymakers, and you're not interested in modifying controllers, then any common Infineon controller will suit your needs.

"More FETS is better" logic is about the same as the "More cookies is better" logic most 5 year olds poses. Both can leave you over weight. For a motor like a MAC, a 6 to 9 FET controller is all they need. Increasing the FET count does make them run a little cooler, but that's only a benefit if you're taking the motors to the bleeding edge of performance, and you find the controller is getting too hot. I'm pushing 10,000 watts through a 18FET controller. It rarely gets warm.

There are a few people who might build you a high performance bike if you wave enough cash at them, but I think the general consensus is that it's a bad idea. If you ever watch Formula 1 racing, then you've seen how awesome those cars are as they fly around the track. And what you probably ignore is the support crew. It can take a crew of 30 people, working full time jobs year round, dedicated to keeping just 1 car running for 20 races or so a year.
With an Ebike, you don't have a crew. you have your self. and if you want a bike that balances on the line between awesome and firey explosions, you have to know every nut and bolt, every wire and cable, every spoke and bearing on the bike, and be able to maintain, fix, or replace every part before it fails in some epic death causing way. The only real way to know a bike that intimately is to design and build it your self.
 
I hear you Drunkskunk :) I just need to get my fingers dirty :D
Well that actually make sense, even if I don't know what I am doing right now. I guess learning is part of the fun and pride.
And if things goes sideways I at least will know how to make any needed changes.

If you look at the specs of the duty cycle, it uses close to a hundred 18650 Panasonic Li Io batteries @ 2900-mAh per cell.That should be 290 Ah or close. 57 volt total. Or 14S /7P = 1140 WH capacity. Still he manage to run 2WD without any additional cooling of the geared hub's or the controllers.

In layman terms that translates into 70 kmp top speed, enough torque to climb any street or public road hill and a range of close to 3 hours of riding at good speed. As he does not need to use any extra cooling does that mean adding another 50 batteries would make for 85 volt and 1710 WH? At that voltage surely the controllers and motors must start to meet their limits. Point is his set up seems to great for every day riding without pushing things too far. 70 kmh on a bicycle that top notch in my book. And if we say maybe a sustained speed of 35-40 kmp during commute to work that would be great.

But as one eventually get set for sure on what hardware to get and it all arrives @my door wouldn't be better to make some small modding to the motors for even faster heat dissipating and lower heat build up? From what I've read people drill holes and soak the internal of motors with transmission fluids, and that oil cools the internal more rapidly. Is there any disadvantages to get this modd done prior to assembly the bike? I mean more then likely one need to open those babies up anyway, in order to get sensors in there for monitoring the temperatures. Mineral oil is non conductive and should not cause corrosion or wear down isolation on any of the wires.
 
Maybe you just want to make this complicated, but just about any fairly cheap direct drive hubmotor, when installed front and back, and run on 72v controllers will get you in the 40 mph club, and not fry the motors.

1500w per motor. Controllers can be weak, like 20 amps because 40 amps is really plenty. I really like my little lyens 72v 20 amps. But cheaper options have got to be out there. You can just run 3000w on one motor if your trips will be short.

1500w on a front hub!!!??? Sure, just use double torque arms. Bear in mind, with a double motor, you will rarely see the full 1500w of torque on either hub.

Start with one hub on the rear, you may be surprised and never need the front one.
 
@Dogman

The thing about Direct Drive hub motors are that they don't do to well on steep hills. And me being a "heavy rider" weighing in at 110 kilo I don't think direct drive motors will do it for me. Not only because I am heavy but also because there are a lot of ups and downs hills on the way to work.

That is why I kind of got hung up on the geared hub motors. As they will spin like 5 times faster then the wheel when needed. Also I kind of like the lighter weight of those.

On a side note I just discovered the Adaptto E-Drives Lab controllers and they seems like a well designed product to choose. Heck those even have traction control, cruise control, overheating protection, 3 adjustable power settings etc. Supposedly those controllers run cool, and can handle a lot of peak power and amp so maybe one can whip those geared hub motors to do 40 mph without risking a meltdown as thermo sensors would limit the power before things get too hot.

Only thing they are missing over at the E-drives Lab is a gyro sensor connected to the controller that will let us have a wheelie mode, like the Audi e-bike. :lol: :lol: :lol:

Imagine flicking a switch or even use your smartphone to enable "wheelie mode" and never go past the balance point. Sweet.

[youtube]5_h-WxZgMfM[/youtube]
 
The limit on the power of a controller and a motor is how much heat they can absorb and shed. I would never consider using a single MAC and 12-FET to ride continuously over 30-MPH (in traffic) and on steep uphills, but...when you double the FETs and copper mass of the stator...you have a combined widths of 44mm in the stators (double copper mass), and 24-FETs to handle the amps (heat) that is flowing through the controller. a 12-FET + a 6-FET would be equal to a single 18-FET?

The Cromotor has a 50mm wide stator (it is also a larger diameter, but still...)

I have never ridden a 2WD E-bike, but the three guys who have...they all posted the details and say the same thing, and none of the three have been prone to exaggeration in the past. (I agree on double torque-arms front and rear)

Make no mistake, this would be an expensive system. I would recommend one of em3ev.com's 40A capable battery packs made from 18650's, with controllers set to send 23A to the rear motor (through a 12-FET), and 17A to the front motor (through a 6-FET), and if you're certain you'll use only 50V, specify the cooler-running 3077-FETs.

50V X 40A = 2,000W

If you get the upgraded MACs with temp sensors and thinner laminations, you could go to

60V X 50A = 3,000W (LiPo battery, 30A/20A split on the same 12-FET/6-FET controllers, but with 4110 FETs)

Again, I have never done this...
 
For a single-motor alternative, 30+ MPH would need at least 72V (18S LiPo) and 40A. (more would be better)

72V X 40A = 2,880W

Rear Crystalyte H40, double torque-arms, 18-FET 4110 controller with double fans (one pushing air in, the other pulling out), hub sideplates ventilated with holes to let the excess heat out.

The beefier Crown and Cromotor are much more expensive, and they would barely get warm at 35-MPH.
 
Thx spinningmagnets for your thoughtful replies. And much appreciated articles on electricbike.com. Keep it up dude :)
I have come over the Adaptto Controller and from the looks of it by reading that thread it seems Adaptto controllers will give you everything short of wheelie mode :D

They have embedded heat sensors and one can adjust the controller based on what battery one runs. As soon as heat builds up the controller will limit the voltage and amp till things cools down. Not a complete stop but it will ease back enough to avoid melting or fried controller. It even has a build in charger so one will save some money on not needing to buy that extra charger.

So what I think at the moment is to carefully look for great deals on batteries and buy as many as I can afford. Based on the price I can get I will then decide what kind of voltage/amp I will run. If I get good deal somewhere I just might get as many batteries as the Adaptto can handle :D
Well to be serious I think 72 volt will me manageable. Maybe even more.

So if that will the path I take I am a little unsure as the if I will need to make liquid cooling or not. That thread was really great and informative but I still can't picture how the heatsink/pipes were embedded into the hub motor. As for pumps, radiators and fans those are dirt cheap and reliable. The only problem will be if I can muster enough craftsmanship to rebuild the motor. For several years I was into o/c and water cooling for PC. So I know where to source parts and what to get.

But for the fun of it, lets assume I will be able to modify the geared hub motor. And lets say I can get a 72v or 96v battery pack.
What kind of average speed do you think I will be able to get from 2 liquid cooled hub motors when exploring the limits? Top speed close to 60 mph? Sustained speed of 40-45 mph on my commute? Is there any way to calculate this, like a formula? Or even better maybe a website that does this for you? Like change volt and amp to see how that will change top speed, sustained speed and predicted melting point?
 
I commute 16Km everyday, the kit I started out with was a 1000W Direct Drive hub motor, and a Lithium Ion 48v 15AH battery. 30mph all the way, everyday, reliable setup.

I'm also commuted with a BMC Geared motor briefly, 40mph top speed on 75volts. Very torquey motor and powerful but the motor heats up very quickly and you can't "crank" the throttle quickly or the gears would slip, its just not as durable as a direct drive.

I have direct drive setups that I commute with that regularly hit 40mph+, and are reliable.
 
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