5kW or 10kW for mid-drive?

[Magnetic]

Hello folks!

I'm a great fan of this forum.
I came for a dream(goal-whatever you call) the very same reason like most of you. I am looking forward to make an e-bike. I want to keep it short but Heck, i can't. I love bicycles and motorcycles. I want to go green with a bicycle. Once I started with my plannings I had my first questionon my mind. I have 2 options, here they come;

1.
Model: HPM5000B -- High Power BLDC Motor
Voltage:48V/72V/96V/120V
Rated Power:3KW-7.5KW
Efficeincy: 91%

2.
Model: HPM-10KW -- High Power BLDC Motor
Voltage:48V/72V/96V/120V
Rated Power:8KW-20KW
Efficeincy: 91%

I will build mid-drive e-bike.
I wont disable bike's gears since place where i live has lots of hills.
I will be able to use lots of LiPo battery but let's say,i will get 10 Hobby King - Turnigy Lipo - 6S 20C @ 5AH 30S 2P configuration.

The question is, with either of these 2 motors, with 350-400lb weight, what would be the difference in terms of mile and mph? And would i push motors to the limits lets say with more Amps? beyond 10kw of motor power?

I'm really excited for your answers! They mean a lot to me.

Source: http://www.goldenmotor.com/

 

[izeman]

5 and 10kw are both way too much for bicycle chains

 

[Magnetic]

Alright, you are right. But what if chain is not an issue for this time? Please tell me something with my questions. Thanks for your interests

 

[neptronix]

It will be an issue instantly.
You can only do motors this powerful if you go with a direct rear drive.

The 5kW motor is about 22-24lbs and is huge. You will also have to figure out a place to mount it. This is going to require a custom frame or an extremely ugly and kludgy motor mount.

I believe you do not know what you are getting yourself into

 

[izeman]

i guess noone has used both of these motors to compare them to each other.
there where some tries for the smaller one, and luke seems to have tried on as well.
but a comparison of those two is a bit much asked for
we can just give general advise about things we've got knowledge of ...

 

[Magnetic]

Ehhehe you all are, right So, an idea of motorcycle conversation would sound good with this build? Should I open a topic on e-moto section? What would you say about those questions if I make a e-moto with it?

 

[spinningmagnets]

If you use the smaller motor, you could put together something similar to the pic below (Luke, on his "deathbike"). I like to call that style a left-side-drive. #415H chain and sprockets would be the lightest I'd attempt to use, and #428 would definitely be strong enough. What controller would you use? Perhaps a Lyen 18-FET using 18S LiPo (65V-74V, 3.6V per cell when low, 4.1V when charged) just for a start?

You haven't mentioned the tools and experience you have, or your budget. Going fast takes a lot of money.

Here's an article that might help you get started:

http://www.electricbike.com/diy-mid-drive/

edit: Here's farfles electromotard. if you like this, consider one of "John in CR"s non-hub motors (http://endless-sphere.com/forums/viewtopic.php?f=28&t=48439&p=713337#p713337).

http://endless-sphere.com/forums/viewtopic.php?f=12&t=49359

 

[Magnetic]

If you use the smaller motor, you could put together something similar to the pic below (Luke, on his "deathbike"). I like to call that style a left-side-drive. #415H chain and sprockets would be the lightest I'd attempt to use, and #428 would definitely be strong enough. What controller would you use? Perhaps a Lyen 18-FET using 18S LiPo (65V-74V, 3.6V per cell when low, 4.1V when charged) just for a start?

You haven't mentioned the tools and experience you have, or your budget. Going fast takes a lot of money.

Here's an article that might help you get started:

http://www.electricbike.com/diy-mid-drive/

edit: Here's farfles electromotard. if you like this, consider one of "John in CR"s non-hub motors (http://endless-sphere.com/forums/viewtopic.php?f=28&t=48439&p=713337#p713337).

http://endless-sphere.com/forums/viewtopic.php?f=12&t=49359

Hello!Thanks for your time I think its better for me to go with motorcycle conversation. My weak point on this plan is, I'm really new so no experience at all. But my strong point on this plan is, I have a factory where I can actually build frames etc. Maybe building an e-motorcycle would be better, what do you think? You catched so good points, thanks !

 

[John in CR]

Since you have the facility, obtain the lightest motorcycle components you can and build as light a motorcycle as possible using 4130 steel. If you have the ability to heat treat something the size of a frame, then 4140 will work too. Include as much space as possible where you would typically find the motor and gas tank on a motorcycle allocated for batteries.

What kind of performance are you looking for? Street riding or off-road?

Since it's almost as easy to build 2 or 3 as to build one, maybe we can work out some kind of trade. Be prepared to not like motorcycles nearly as much anymore.

John

 

[Magnetic]

Since you have the facility, obtain the lightest motorcycle components you can and build as light a motorcycle as possible using 4130 steel. If you have the ability to heat treat something the size of a frame, then 4140 will work too. Include as much space as possible where you would typically find the motor and gas tank on a motorcycle allocated for batteries.

What kind of performance are you looking for? Street riding or off-road?

Since it's almost as easy to build 2 or 3 as to build one, maybe we can work out some kind of trade. Be prepared to not like motorcycles nearly as much anymore.

John

Thanks for your interests!

I think this way will be much better. I will make the frame with required dimensions for motor and batteries.

I am looking for street riding performance. It should have 65mph or up speed limit with 50-60 miles range. These numbers are lower limits so neither I, nor anyone else can say no to 80+ mph with 80+ miles range.

If we think of these goal, 400Ib machine would be better with 5kw or 10kw motor in it? I dont even know if golden motor are any trustable firm... That is the first question. And I need advises from you beautiful people

To summarize, our starting point would be, 400Ib weight should get to those numbers. What would be next choices on motor and battery? Will these goldenmotors be enough or will they suck cuz of their quality...

I am so much excited with this project.. And yes we can dear John Why not share the love, right?

 

[Samd]

John is just being honest with you - because people have started to go there and found that certain components start to fail.

Listen to the comments above - people are trying to save you time and money.
You're confusing being 'negative' with being constructive. It's often necessary in life.

The GNG guys are also finding that bike rear sprockets have a torque limit and start to fail well before the typical power ratings you are chasing. Let these people save you some time. Extra time reading will be quicker overall. That's what the forum is for.

 

[boostjuice]

Heres one of Luke's death-bike before the HPM-10000B got swapped out for the modified ZF-75 frame-based Zero motor

 

[Hillhater]

With either of those motors you may as well forget any pedal assist system.
Your performance, ..speed, acceleration, range, etc will mostly be determined by the battery and controller choices.
Those choices are dictated by you own limitations, ..cost, weight, space, etc
Ideally you would get 3kWhr , 100v, of EIG performance cells and a top line Sevcon controller etc..
.... but in reality you probably wont !

 

[Magnetic]

Dear Samd, I am listening, thats why I am here at the first place. Also I'm aware of the comments and peoples kind helpings. This is my second home, really! I am also aware of torque limit of rear sprockets. They will require torque arms, i do know that. I said

''I think its better for me to go with motorcycle conversation''

Thanks for your interests.

Dear Hillhater, I wrote what I am capable of. I wrote what my motor and battery options would be. I wrote what weight would my build be. I asked questions and need answers to them. I do know what you are saying, but come to see of it, its not helping me. I will be happy once you answer to what I do not know( my questions)

I wrote this topic to e-bicycle because it is a mid drive motor I am asking for. My plan has changed a little bit as you see in this topic. I will build my own motorcycle frame and to stay on topic, my questions are mid drive motors as I stated at my first post. So, please lets stay clear and if you know about my questions, please help me with your knowledge and experience.

Greetings from Czech Republic.

 

[John in CR]

Since you have the facility, obtain the lightest motorcycle components you can and build as light a motorcycle as possible using 4130 steel. If you have the ability to heat treat something the size of a frame, then 4140 will work too. Include as much space as possible where you would typically find the motor and gas tank on a motorcycle allocated for batteries.

What kind of performance are you looking for? Street riding or off-road?

Since it's almost as easy to build 2 or 3 as to build one, maybe we can work out some kind of trade. Be prepared to not like motorcycles nearly as much anymore.

John

Thanks for your interests!

I think this way will be much better. I will make the frame with required dimensions for motor and batteries.

I am looking for street riding performance. It should have 65mph or up speed limit with 50-60 miles range. These numbers are lower limits so neither I, nor anyone else can say no to 80+ mph with 80+ miles range.

If we think of these goal, 400Ib machine would be better with 5kw or 10kw motor in it? I dont even know if golden motor are any trustable firm... That is the first question. And I need advises from you beautiful people

To summarize, our starting point would be, 400Ib weight should get to those numbers. What would be next choices on motor and battery? Will these goldenmotors be enough or will they suck cuz of their quality...

I am so much excited with this project.. And yes we can dear John Why not share the love, right?

400lbs is a pig and even the 10kw motor won't be remotely fun. Realistically how often will you ride 50-60 miles before being able to reach a plug? Sure build it to fit a 60mile battery, but ride it with a 20mile battery first, so you understand the effect on power to weight. With electrics the difference isn't masked by clutches, big drive train losses, and multiple gearing, and you quickly appreciate power to weight. How much do you weigh by the way?

If you can't get the bike with battery below 200lbs, then buy Zero's 2013 motor and tuned Sevcon controller to match, but still keep it below 300lbs.

You have an opportunity to build something more interesting and fun to ride than anything you've ridden before, so you'll sell yourself short by spending 3-4X the money than my 137lb ebike that pushes my 270lb self to 100mph, but end up with lackluster performance that even my cargo bike would run rings around. I started with an emoto, though more like 600lbs due to the lead batteries, and every ebike I've made had better performance than pigmoto. After 5 years I do have another street emoto in mind now that raw batteries can be had for under $250/kwh, but it's going to have dual motors with one in the wheel with a big honking 8kwh battery and still weigh under 250lbs and be very slippery through the air for good economy at useful speeds. Above 30mph aero is everything if you're interested in range. It's not like gas where 37kwh gross (10kwh effective) is stored in one gallon and weighs only 6lbs.

John

 

[Magnetic]

Since you have the facility, obtain the lightest motorcycle components you can and build as light a motorcycle as possible using 4130 steel. If you have the ability to heat treat something the size of a frame, then 4140 will work too. Include as much space as possible where you would typically find the motor and gas tank on a motorcycle allocated for batteries.

What kind of performance are you looking for? Street riding or off-road?

Since it's almost as easy to build 2 or 3 as to build one, maybe we can work out some kind of trade. Be prepared to not like motorcycles nearly as much anymore.

John

Thanks for your interests!

I think this way will be much better. I will make the frame with required dimensions for motor and batteries.

I am looking for street riding performance. It should have 65mph or up speed limit with 50-60 miles range. These numbers are lower limits so neither I, nor anyone else can say no to 80+ mph with 80+ miles range.

If we think of these goal, 400Ib machine would be better with 5kw or 10kw motor in it? I dont even know if golden motor are any trustable firm... That is the first question. And I need advises from you beautiful people

To summarize, our starting point would be, 400Ib weight should get to those numbers. What would be next choices on motor and battery? Will these goldenmotors be enough or will they suck cuz of their quality...

I am so much excited with this project.. And yes we can dear John Why not share the love, right?

400lbs is a pig and even the 10kw motor won't be remotely fun. Realistically how often will you ride 50-60 miles before being able to reach a plug? Sure build it to fit a 60mile battery, but ride it with a 20mile battery first, so you understand the effect on power to weight. With electrics the difference isn't masked by clutches, big drive train losses, and multiple gearing, and you quickly appreciate power to weight. How much do you weigh by the way?

If you can't get the bike with battery below 200lbs, then buy Zero's 2013 motor and tuned Sevcon controller to match, but still keep it below 300lbs.

You have an opportunity to build something more interesting and fun to ride than anything you've ridden before, so you'll sell yourself short by spending 3-4X the money than my 137lb ebike that pushes my 270lb self to 100mph, but end up with lackluster performance that even my cargo bike would run rings around. I started with an emoto, though more like 600lbs due to the lead batteries, and every ebike I've made had better performance than pigmoto. After 5 years I do have another street emoto in mind now that raw batteries can be had for under $250/kwh, but it's going to have dual motors with one in the wheel with a big honking 8kwh battery and still weigh under 250lbs and be very slippery through the air for good economy at useful speeds. Above 30mph aero is everything if you're interested in range. It's not like gas where 37kwh gross (10kwh effective) is stored in one gallon and weighs only 6lbs.

John

You know, excitement makes us sometimes impatient, this time I was impatient. but your advises cools me down, now I am patiently doing more researches. Once or twice a day I think. Why I said ''I think'' because we do notknow what its capable of atm. I will do it that way, taking it easy with 20 mile battery pack.

You are right... 400Ibs too much of weight. Since I will build the frame myself, it will be lighter. Just motor, frame and batteries and me. It wont pass 200-250lbs I think. And I am 150lbs

Thing with Zero is, I want to make my own ride. That is the spirit I have at the moment.

You are absolutely correct. I am sorry with pigmoto, but seems bad investment came back as good lessons and experiences ! Thats a great idea you have in your mind, it would be really economical like you said.

What I've learned is that,
http://forums.aeva.asn.au/forums/10kw-bldc-from-golden-motor-model-hpm10kw_topic2544.html I will not use golden motor Now I made one step backwards. Now I am looking for a BLDC motor I am looking for 10kW+ do you know any such motors where can we buy with cute warranty?

 

[christerljung]

The GNG-setup for power about 2kw continous and 6kw peak is pretty awesome.
You can build something at 25kg with 24s 5ah batteries onboard.
6kw and a weight about 25kg gives a nice accelleration and top speed about 80kph.
About the final drivetrain a standard shimano HG 7/8-speeed holds up fine for many hours, as long as you dont hit the smallest 11 cogg.

I got about 150 hours on my Kona stinky with this setup mentioned above.
But i havent done any longer rides.