Will this bike work for a 16KW build?

Haien

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So I'm planning the project of building a high power ebike. Originally I was going to e-convert a dirt bike with a qs 273 50H, but came to the conclusion that doing a downhill bike build would be better as I then can use it to commute, and not only ride my build in the woods. I will be using a qs 205 4T, with the sabvoton 72200 and a 22s battery capable of 200A peak. As I want the bike to be really stealthy, I am planning to use a back pack battery. The only problem I have now is finding the right bike. There are not too many dh bikes in my area.

This is one of the only ones I found, do you think I can make this work for peak 16KW in some way? It is a Norco Six bike.
Screenshot_2021-06-23-12-48-54-59.jpg
 
[strike]Not much room for a pack capable of 16kw peak unless you go under the down tube.[/strike] What is the dropout spacing on the rear? A qs 273 50H motor will probably need at least 150mm spacing.
 
pwd said:
Not much room for a pack capable of 16kw peak unless you go under the down tube. What is the dropout spacing on the rear? A qs 273 50H motor will probably need at least 150mm spacing.

As I said, I am planning to go with a back pack battery. Hm, I dont know, that may be a problem.
 
AFAIK, bikes with 142 - 148 mm rear spacing are thru axle, so you'd need to locate a motor with that configuration. Possibly you'll need to fabricate some type of rear "dropout/torque arm" and graft it on.
 
2old said:
AFAIK, bikes with 142 - 148 mm rear spacing are thru axle, so you'd need to locate a motor with that configuration. Possibly you'll need to fabricate some type of rear "dropout/torque arm" and graft it on.

There are certainly 150mm bikes with dropouts, but I am afraid the one I found is only 135mm
 
This thread has a couple of examples of custom dropouts for fitting the QS205:
https://www.endless-sphere.com/forums/viewtopic.php?f=6&t=90988
 
E-HP said:
This thread has a couple of examples of custom dropouts for fitting the QS205:
https://www.endless-sphere.com/forums/viewtopic.php?f=6&t=90988

Thank you!
 
Haien said:
So I'm planning the project of building a high power ebike. Originally I was going to e-convert a dirt bike with a qs 273 50H, but came to the conclusion that doing a downhill bike build would be better as I then can use it to commute, and not only ride my build in the woods. I will be using a qs 205 4T, with the sabvoton 72200 and a 22s battery capable of 200A peak. As I want the bike to be really stealthy, I am planning to use a back pack battery. The only problem I have now is finding the right bike. There are not too many dh bikes in my area.

This is one of the only ones I found, do you think I can make this work for peak 16KW in some way? It is a Norco Six bike.
Screenshot_2021-06-23-12-48-54-59.jpg

Why not use a leafmotor/leafmotor clone “1500W” (35mm stator) that is capable to 3000W without modification and 5000W bursts? They come in 135mm axle length so much easier to find a bike that will fit. Tons of speed and hill climbing power for any bicycle.

At the 16kw power level, you are pretty much building an electric motorcycle that needs real motorcycle parts strength. A DH bike is the absolute bare minimum for handling that much power. You will need to make a lot of stuff on your own to make it work without disintegrating. QS273 weighs like 30lbs if I’m not mistaken. That Norco Six (more like an all-mountain bike a bit more trail friendly than a Norco A-line but still burly) is probably 40-45lbs. That motor is a whole lot of unsprung weight. You need a huge pack (at least 8-10p so hundreds of cells) to be able to feed a controller that justifies having such a powerful motor. I see no easy way to mount a 13-20s/10p pack on that bike. Most likely that biggest reasonable pack on a bike like that would be 13-14s/6-8p. Even then you’d have to get creative with making your own to fit or custom mounts and cases.

Even the QS205 is pushing it weight wise on a bicycle. 273 even more so. The 1500W leafmotor is like 12lbs and while still heavy it doesn’t completely ruin the bicycle aspect of the build.

Before you order your motor you should figure out if you really want to build an all out fast 16kW e-Moto with 25lbs of batteries, a 30lb motor, and a 50lb bike. Will be a much different riding experience than a DH bike with 2kW.
 
ben2401 said:
Haien said:
So I'm planning the project of building a high power ebike. Originally I was going to e-convert a dirt bike with a qs 273 50H, but came to the conclusion that doing a downhill bike build would be better as I then can use it to commute, and not only ride my build in the woods. I will be using a qs 205 4T, with the sabvoton 72200 and a 22s battery capable of 200A peak. As I want the bike to be really stealthy, I am planning to use a back pack battery. The only problem I have now is finding the right bike. There are not too many dh bikes in my area.

This is one of the only ones I found, do you think I can make this work for peak 16KW in some way? It is a Norco Six bike.
Screenshot_2021-06-23-12-48-54-59.jpg

Why not use a leafmotor/leafmotor clone “1500W” (35mm stator) that is capable to 3000W without modification and 5000W bursts? They come in 135mm axle length so much easier to find a bike that will fit. Tons of speed and hill climbing power for any bicycle.

At the 16kw power level, you are pretty much building an electric motorcycle that needs real motorcycle parts strength. A DH bike is the absolute bare minimum for handling that much power. You will need to make a lot of stuff on your own to make it work without disintegrating. QS273 weighs like 30lbs if I’m not mistaken. That Norco Six (more like an all-mountain bike a bit more trail friendly than a Norco A-line but still burly) is probably 40-45lbs. That motor is a whole lot of unsprung weight. You need a huge pack (at least 8-10p so hundreds of cells) to be able to feed a controller that justifies having such a powerful motor. I see no easy way to mount a 13-20s/10p pack on that bike. Most likely that biggest reasonable pack on a bike like that would be 13-14s/6-8p. Even then you’d have to get creative with making your own to fit or custom mounts and cases.

Even the QS205 is pushing it weight wise on a bicycle. 273 even more so. The 1500W leafmotor is like 12lbs and while still heavy it doesn’t completely ruin the bicycle aspect of the build.

Before you order your motor you should figure out if you really want to build an all out fast 16kW e-Moto with 25lbs of batteries, a 30lb motor, and a 50lb bike. Will be a much different riding experience than a DH bike with 2kW.

It may have been unclear, but what I want is really an almost too powerful e-moto. I never wanted this build to be a bicycle with an assisting motor, I want it to be an electric motorcycle disguised as a bicycle. As I said, I originally planned to e-convert a dirt bike, but figured I might use my build much more if it is more stealthy and can be ridden (slowly) through the city without getting attention of police. I want this bike to be that dirt bike, but disguised as a bicycle.

As said before, twice, I will use a back pack battery, both for the stealth aspect, and also because my 22s pack won't fit too well on the frame.
 
Your challenge, as stated above, is to locate a "bike-like" frame that will handle the power you desire. This doesn't exist AFAIK. Motors strong enough have 150 mm dropouts and bikes with that width dropouts have through axles. The motorcycle-like bikes most build have Stealth-like frames.
 
Haien said:
E-HP said:
This thread has a couple of examples of custom dropouts for fitting the QS205:
https://www.endless-sphere.com/forums/viewtopic.php?f=6&t=90988

Thank you!

When you fabricate the dropouts, I think extending the swingarm length by 2 or 3 inches would be a good idea.
 
E-HP said:
Haien said:
E-HP said:
This thread has a couple of examples of custom dropouts for fitting the QS205:
https://www.endless-sphere.com/forums/viewtopic.php?f=6&t=90988

Thank you!

When you fabricate the dropouts, I think extending the swingarm length by 2 or 3 inches would be a good idea.

I think so too. Though it won't be on this bike as I think it's 135mm, will have to find something with 150mm first.
 
2old said:
Your challenge, as stated above, is to locate a "bike-like" frame that will handle the power you desire. This doesn't exist AFAIK. Motors strong enough have 150 mm dropouts and bikes with that width dropouts have through axles. The motorcycle-like bikes most build have Stealth-like frames.

I may have to get a bike with 150mm dropouts and fabricate my own sturdy steel dropouts. The question now is how I will do that. I also have to find a dh bike with 150mm dropouts.
 
Haien said:
It may have been unclear, but what I want is really an almost too powerful e-moto. I never wanted this build to be a bicycle with an assisting motor, I want it to be an electric motorcycle disguised as a bicycle.

Please consider not doing that. If you ride a motorcycle, make it legal and keep it in places where motorcycles are welcome. Cyclists have enough problems without you becoming another one.
 
Haien said:
pwd said:
Not much room for a pack capable of 16kw peak unless you go under the down tube. What is the dropout spacing on the rear? A qs 273 50H motor will probably need at least 150mm spacing.

As I said, I am planning to go with a back pack battery. Hm, I dont know, that may be a problem.

Impossible. You will have either a heavy battery with a very small range with LIPOs, or an extremely heavy battery with 18650.
You will get tired of that weight after 5 minutes.
 
Chalo said:
Haien said:
It may have been unclear, but what I want is really an almost too powerful e-moto. I never wanted this build to be a bicycle with an assisting motor, I want it to be an electric motorcycle disguised as a bicycle.

Please consider not doing that. If you ride a motorcycle, make it legal and keep it in places where motorcycles are welcome. Cyclists have enough problems without you becoming another one.

I won't be a problem to cyclists if I go bicycle speed where other bicycles are. Going with 16kw instead of 1kw won't make a difference as long as I don't make it a problem.
 
Tommm said:
Haien said:
pwd said:
Not much room for a pack capable of 16kw peak unless you go under the down tube. What is the dropout spacing on the rear? A qs 273 50H motor will probably need at least 150mm spacing.

As I said, I am planning to go with a back pack battery. Hm, I dont know, that may be a problem.

Impossible. You will have either a heavy battery with a very small range with LIPOs, or an extremely heavy battery with 18650.
You will get tired of that weight after 5 minutes.

The battery will be 22s and 20Ah, weighing right around 10kg. With a comfortable back pack that will be no problem.
 
Haien said:
Chalo said:
Haien said:
It may have been unclear, but what I want is really an almost too powerful e-moto. I never wanted this build to be a bicycle with an assisting motor, I want it to be an electric motorcycle disguised as a bicycle.

Please consider not doing that. If you ride a motorcycle, make it legal and keep it in places where motorcycles are welcome. Cyclists have enough problems without you becoming another one.

I won't be a problem to cyclists if I go bicycle speed where other bicycles are. Going with 16kw instead of 1kw won't make a difference as long as I don't make it a problem.

A Harley Livewire rider could say the same, but he'd also be wrong.
 
Haien said:
I won't be a problem to cyclists if I go bicycle speed where other bicycles are. Going with 16kw instead of 1kw won't make a difference as long as I don't make it a problem.
Y'know, everyone says that. Then when they get yelled at/ticketed for riding too fast, they claim it's the other person/cop's problem.

If you are going to ride with other bikes, get a ~2kW motor and use a DH frame. That will easily push you to unsafe speeds, and you'll be able to keep up with slow traffic. It will also allow you to use a standard bike frame without too much in the way of mods.

If you want to ride fast on the street with car traffic, get an appropriate frame and build it for that speed - including an on-frame battery. (You don't want to think too much about what hitting the ground at 40mph wearing a 50lb battery would look like.)

No one is going to think "oh, that's just a completely legal ebike, nothing special" if you are pacing them at 60mph.
 
JackFlorey said:
Haien said:
I won't be a problem to cyclists if I go bicycle speed where other bicycles are. Going with 16kw instead of 1kw won't make a difference as long as I don't make it a problem.
Y'know, everyone says that. Then when they get yelled at/ticketed for riding too fast, they claim it's the other person/cop's problem.

If you are going to ride with other bikes, get a ~2kW motor and use a DH frame. That will easily push you to unsafe speeds, and you'll be able to keep up with slow traffic. It will also allow you to use a standard bike frame without too much in the way of mods.

If you want to ride fast on the street with car traffic, get an appropriate frame and build it for that speed - including an on-frame battery. (You don't want to think too much about what hitting the ground at 40mph wearing a 50lb battery would look like.)

No one is going to think "oh, that's just a completely legal ebike, nothing special" if you are pacing them at 60mph.

I will mostly ride to and from the city, which is about a 6 mile ride each way on a bicycle path with barely any cyclists on at all (typically I'd meet about 1 cyclist when I used to cycle that path) and an old road with almost no cars or bikes (typically would not meet a single car). In the city I will go bicycle speeds, no more than 20mph. I am not planning to go motorcycle speeds even close to all the time, as that would kill my range and be overall dumb. The reason I want so much power is simply to have stupid high torque and acceleration up to like 30mph, which I will get with 200A and a qs 205 4t. I already have an 1kw bike that goes 30mph, the speed is ok, ideally I would want to go maybe 37 (60kmh), but the acceleration is underwhelming.

Some of you might not understand this, but the qusetion I am essentially asking this forum is how I should go about building my 16kw bike, not if I should build my 16kw bike.
 
Chalo said:
Haien said:
Chalo said:
Haien said:
It may have been unclear, but what I want is really an almost too powerful e-moto. I never wanted this build to be a bicycle with an assisting motor, I want it to be an electric motorcycle disguised as a bicycle.

Please consider not doing that. If you ride a motorcycle, make it legal and keep it in places where motorcycles are welcome. Cyclists have enough problems without you becoming another one.

I won't be a problem to cyclists if I go bicycle speed where other bicycles are. Going with 16kw instead of 1kw won't make a difference as long as I don't make it a problem.

A Harley Livewire rider could say the same, but he'd also be wrong.

Another forum member could make a slightly better comparison, and it still wouln't make much of a point.
 
Haien said:
I will mostly ride to and from the city, which is about a 6 mile ride each way on a bicycle path with barely any cyclists on at all (typically I'd meet about 1 cyclist when I used to cycle that path) and an old road with almost no cars or bikes (typically would not meet a single car). In the city I will go bicycle speeds, no more than 20mph. I am not planning to go motorcycle speeds even close to all the time, as that would kill my range and be overall dumb. The reason I want so much power is simply to have stupid high torque and acceleration up to like 30mph, which I will get with 200A and a qs 205 4t. I already have an 1kw bike that goes 30mph, the speed is ok, ideally I would want to go maybe 37 (60kmh), but the acceleration is underwhelming.

Some of you might not understand this, but the qusetion I am essentially asking this forum is how I should go about building my 16kw bike, not if I should build my 16kw bike.
Well, since this is an open forum, you are going to get all sorts of answers, and they may not be ones you like!

16kw is about 20hp, which means it's got more power than a 250cc dirt bike. Those will hit 80mph and have the torque to climb incredibly steep hills - and they have the frame to handle the power. "Stupid high torque" a 16kW motor will have, but that will also mean it will dump you if your hand slips. (It's happened to me.) You will end up with a big, heavy, expensive, inefficient bike that doesn't do its primary job (getting you to the city) well.

Get a 2kW motor with a temp sensor and run it at 3-4kW in a DH frame. That will give you all the torque you could want and will easily hit 30mph. And if you accidentally floor it, it won't break the frame, dump you or break spokes. And it will be reasonably efficient, so your battery pack can be smaller (i.e. more stealthy) and easier to manage. The bike will weigh less, be more nimble, and look far more "bike like."

Or get a 16kW motor and put it in that donor frame you posted at the beginning. Get a huge battery. Make a battery backpack with a big cable leading to the controller that you imagine people won't notice. Bend the dropouts way out to get the hub in. Then when it's all set up, floor it. It will be a learning experience for you, and you'll end up knowing a lot more about ebikes.
 
JackFlorey said:
Haien said:
I will mostly ride to and from the city, which is about a 6 mile ride each way on a bicycle path with barely any cyclists on at all (typically I'd meet about 1 cyclist when I used to cycle that path) and an old road with almost no cars or bikes (typically would not meet a single car). In the city I will go bicycle speeds, no more than 20mph. I am not planning to go motorcycle speeds even close to all the time, as that would kill my range and be overall dumb. The reason I want so much power is simply to have stupid high torque and acceleration up to like 30mph, which I will get with 200A and a qs 205 4t. I already have an 1kw bike that goes 30mph, the speed is ok, ideally I would want to go maybe 37 (60kmh), but the acceleration is underwhelming.

Some of you might not understand this, but the qusetion I am essentially asking this forum is how I should go about building my 16kw bike, not if I should build my 16kw bike.
Well, since this is an open forum, you are going to get all sorts of answers, and they may not be ones you like!

16kw is about 20hp, which means it's got more power than a 250cc dirt bike. Those will hit 80mph and have the torque to climb incredibly steep hills - and they have the frame to handle the power. "Stupid high torque" a 16kW motor will have, but that will also mean it will dump you if your hand slips. (It's happened to me.) You will end up with a big, heavy, expensive, inefficient bike that doesn't do its primary job (getting you to the city) well.

Get a 2kW motor with a temp sensor and run it at 3-4kW in a DH frame. That will give you all the torque you could want and will easily hit 30mph. And if you accidentally floor it, it won't break the frame, dump you or break spokes. And it will be reasonably efficient, so your battery pack can be smaller (i.e. more stealthy) and easier to manage. The bike will weigh less, be more nimble, and look far more "bike like."

Or get a 16kW motor and put it in that $200 frame you posted at the beginning. Get a huge battery. Make a battery backpack with a big cable leading to the controller that you imagine people won't notice. Bend the dropouts way out to get the hub in. Then when it's all set up, floor it. It will be a learning experience for you, and you'll end up knowing a lot more about ebikes.

Any high power motorcycle will dump you if your hand slips, that is not a unique problem for high power ebikes. I will try to mitigate this issue by modifying the throttle response.

"You will end up with a big, heavy, expensive, inefficient bike that doesn't do its primary job (getting you to the city) well.", no I won't. It won't be any bigger than a bicycle, it will be heavy for a bike, but not for a motorcycle, it will not cost more than I am willing to spend, and efficiency will be very good, it is not affected by potential power. It will do its primary job, being a fun toy, well, as well as take me from point a to point b.

No, 4kw will not give me all the torque I could want, 16kw will. I will not build a 2kw peak 4kw ebike with a dh frame as you suggest, nor will I follow your instructions for how to get hurt. What I think I will do is look for a dh bike with 150mm dropouts, for which I will find a way to machine sturdy clamping steel dropouts that will take the ~300nm of torque the qs 205 probably can produce with 200A at 80.3v nom, as this is what I have concluded is the best option after listening to the people giving me the information I am looking for.
 
Haien said:
Tommm said:
Haien said:
pwd said:
Not much room for a pack capable of 16kw peak unless you go under the down tube. What is the dropout spacing on the rear? A qs 273 50H motor will probably need at least 150mm spacing.

As I said, I am planning to go with a back pack battery. Hm, I dont know, that may be a problem.

Impossible. You will have either a heavy battery with a very small range with LIPOs, or an extremely heavy battery with 18650.
You will get tired of that weight after 5 minutes.

The battery will be 22s and 20Ah, weighing right around 10kg. With a comfortable back pack that will be no problem.

Ok, as someone who has ridden with 4.5kg backpack battery, tell me how it goes.
 
Haien said:
Any high power motorcycle will dump you if your hand slips, that is not a unique problem for high power ebikes. I will try to mitigate this issue by modifying the throttle response.

Have you ever ridden a 4kW ebike?

I think the suggestion of trying a high powered ebike makes sense. Try one without a tamed throttle, then try one with a tamed throttle. Then you have a baseline for determining how much additional unusable torque you'll be adding.
 
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