The 10.000W target!

limpsilver

10 mW
Joined
Sep 1, 2014
Messages
27
Hi!

I'm Fabien from France.
I've been reading this forum a lot but almost never post anything.

The story is : my first ebike has been stolen last month :evil: It was a 48V20Ah 35A controller with 9C 10*6 motor on a 26" wheel (classic).

This time I want to go big :D
I want ~10kw and stay light. The goal is power wheelie :mrgreen:
So the power will be used for a really short time and not for high speed (that's why I stay on 4T). My cruising speed will be 45kph (pedaling).

I will try to explain how I will use it (I just ask you to trust me about my usage :wink: ).
A classic day for me will be :
- acceleration with 1000W maximum then cruising @ 45kph (PAS mode)
- I have 1 stop on my way to work -> big power to have some fun (full power for 5 seconds). I'll do that 2/3 times per battery cycle.
- when I reach 45kph -> cruising @ 45kph (PAS mode)

So here is what I bought:
- classic 26" frame with good brakes, something like that: https://i.ytimg.com/vi/h7XcGg9N5l0/hqdefault.jpg with XL frame to put all the stuff in the triangle
- sabvoton 72150 (72V 150A currrent 350A motor, and a lot more with the right software :mrgreen: ). Yes I know it is big! The big challenge is to put it nicely on a classic frame!
- MXUS V3 4T
- 20S6P samsung 25r point welded by myself
- CA V3
- potentiometer
- PAS
- throttle
- torque arm (of course) 14mm
- XT150 connector for motor, AT150 for battery
- bmsbattery charger 72V2A
- point welder
- nickel plates
- 8AWG +14 AWG cable
- AS150 + XT150
- 3mm foam
- Mavic 321 rim
 
Actually, I'll try my best to keep on a classic frame. I'm using my bike everyday and the police office is close to my house :mrgreen: With a classic bike frame it is easier to "talk" with policemen even if the bike is too powerfull...
About the tires: I'm more on big schwalbe tire (super moto for exemple) and I want to stay on 26".
I forgot an important thing, my 10Kw will only be used for power wheelie, not for high speed (that's why I stay on 4T). My cruising speed will be 45kph.

One thing I have not find yet: the bms (20s >=150A peak, 50A continuous). Bestech want to sell me a least 2 pieces. Of course I only need one.
 
Why not use the Adaptto controller and BMS, for high power that it what I would choose.

For the frame I agree with you, the more bike looking it is the better for police to go by unnoticed if you don't speed.
 
I don't want adaptto for 2 reasons:
- a bit expensive
- no PAS (main reason)
I absolutely want PAS and like Merlin my almost only option was Sabvoton!
 
With all that stuff mounted this bike will look like everything, but not a normal bicycle. .... :roll:

And do you really want to go 45 or even more without suspension?

The bicycle tire will fail due to the heavy torque.....not the high speed.
I ripped several bicycle tires apart....including the relatively robust felt bermmaster.
When i switched to moped tires this was no problem anymore.

Also this tiny 6p battery is not a good choice......go 10p at least for 10kw.

And another thing......if your bike is capable of doing 10kw.......you will use it often, thrust me.
Its not like "oh im going 45kph only".....the acceleration is addictive. :wink:
 
It will almost looks like a classic bike if the integration of my controller is good. Everything on the triangle like in my old bike.

Yes 45kph without rear suspension is ok, my old one was doing 50+ kph with no problem (with balloon tire). I'm only riding on road.

My "tiny" battery is capable of more than 150A. Of course battery life will be decreased but I know that. I prefer buy 2 tiny battery more than one big (because of thief). When the battery will be dead (1 year, 2 maybe), I'll doing a bigger maybe.

I know exactly how I will use my bike, don't worry :wink: On my last bike I had 1600W and I was using only 600W 99% of the time. Remember I'm always pedaling :wink:
 
I dont have your discipline. ...... i always want to see what range i get when i only use 50A.....after 10km i switch to 120A. :lol:

I dont like compromises, if you know what you need then everythings fine.

Paperwise the 25r is capable of 150A (barely) at 6p......but i wouldnt abuse my battery this way.
I have 19p and drain max. 120A.

Wish you the best with your project.
 
Go for it limp silver. Can't wait to see photos. 8)
 
After two days negotiating bestech agree to sell me only one BMS.
So now I can choose between :
-this one, Riba233 told me it is working fine
http://fr.aliexpress.com/item/20S-Li-ion-Lipo-Batteries-Protection-Board-BMS-System-72V-84V-80A-Continuous-Discharge-Current/32500068377.html?spm=2114.01010208.3.1.0yHtE5&ws_ab_test=searchweb201556_10,searchweb201602_3_10057_10056_10055_10017_10059_10058_10060_10061_413_10062,searchweb201603_1&btsid=7b7db1b4-ce37-420f-92b3-d4071ad6ea6a
- or the one from bestech : http://www.bestechpower.com/64v20spcmbmspcbforlifepo4batterypack/BMS-D138V1.html

The price is not the same!
Bestech $138, Ali $40

Is the bestech really better?

cwah said:
Get smaller wheel like 20" for better thrust
Yes, you're right but I want it to look as much as possible to a bike. I'll try 26" at first and see the result.

ziltoid81 said:
I dont have your discipline. ...... i always want to see what range i get when i only use 50A.....after 10km i switch to 120A. :lol:

I dont like compromises, if you know what you need then everythings fine.

Paperwise the 25r is capable of 150A (barely) at 6p......but i wouldnt abuse my battery this way.
I have 19p and drain max. 120A.

Wish you the best with your project.
Exactly we don't use our bike the same way. For me it is a powerful daily driver bike. For you it is a toy 8)
I know 150A is a lot for 6x25r and they will not like that :shock: But I'm doing my battery by myself for the first time and if I fail I better fail with 400€ cells than with 1200€ of A123 cells :mrgreen:

Wolfeman said:
Go for it limp silver. Can't wait to see photos. 8)
Thanks !
 
limpsilver said:
What do you think about my build?

I think you're talking about at least 10 times the power your bicycle was intended to tolerate.

What advice would you give to a young man who said he plans to raise the output of his Honda Civic to 1500 kilowatts, but expresses no intention to change the chassis, suspension, or tires?
 
Chalo said:
limpsilver said:
What do you think about my build?

I think you're talking about at least 10 times the power your bicycle was intended to tolerate.

What advice would you give to a young man who said he plans to raise the output of his Honda Civic to 1500 kilowatts, but expresses no intention to change the chassis, suspension, or tires?
To ride carefully :wink:

Except that :
- frame is very solid. Is it capable of 30/40kph on trail wich is harder than 70kph on the road. The only problem will be the torque and I will check that carefully. I may need to reinforce rear base. I'll see.
- front suspension. No problem at all on the road since I don't put 203mm disc brake
- brakes : should be enough, elixir are pretty good. If it is not enough, I'll go for 203mm + 20mm front fork.

So, it is not exactly the same...
I did not choose the bike randomly. Is it a strong bike with good equipment.

What do you think about my build EXCEPT for the frame ? :mrgreen:
 
I think you should do either one of two things to improve your chances for a successful project.

1. Change the frame to something that will not be a rubbery snake when riding with 10kw and all the extra weight.
2. Ditch the idea of 10kw and reconsider what you actually need. What are you going to use 10kw for when riding 45km/h all day long?

I am riding my cargobike almost every day, and it can cruise just fine at 45km/h.
I use 600-1000W most of the time. and have the limit set around 2,5kw for heavy hills etc. This is a heavy bike with 20+kg of batteries, still leaves regular mopeds behind no problem.
Over 6000km in one year speaks for how reliable and usable it is, and its still far from perfect.

10kw on a regular bike will most likely be gimmicky, unsafe, and a pretty shit bike in the long run. After the initial hype, you will realize how lackluster the complete package is.
 
limpsilver said:
Exactly we don't use our bike the same way. For me it is a powerful daily driver bike. For you it is a toy 8)

The truth couldnt be more off....... :lol:

I commute to work with my bike every day all year.
Therefore a too tiny battery would be too expensive for me.
Also bike tires are too expensive in therms of Euro per km. :wink:
With that power they got ripped apart too often.

I need my bike every day, therefore everything is chosen to last long.

Guys....there are experiences in life you must do yourself.
Let him go 10kw with that bicycle stuff.

I dont have the money or the balls to buy cheap and at least two times, if he does.....fine.
 
limpsilver said:
What do you think about my build EXCEPT for the frame ?

I think you'll go faster than 100 kph unless you make some mistake in matching motor speed to road speed. If your battery voltage times the kV of your motor equals more than 130 kph at the wheel, then I think you'll get at least 100 on the road.

I think pedaling doesn't do very much at speeds over 50 kph. So you don't need gear ratios for higher speeds than that.

I think heavy bikes are less fun than light ones, and your performance target requires a heavy bike.

I recommend 2 ply Maxxis Hookworm tires if you can get them. That's a much stronger casing than necessary for a bicycle, maybe strong enough for what you have in mind.
 
Well,, practice riding 40 mph on just the front wheel. That's what happens when you hit a bump you didn't see in time, with no rear shocks. It's really fun. 8)

This is no joke, it does happen. Ripping up a tire in 45 min happened to me too. This is one reason I got the welder, and started modifying frames.

Making them longer, and stiffer, and able to handle a smaller wheel without making the headset angle funny or having the pedals strike the ground. My bike looks funny, but no cop here thinks it's an illegal home made motorcycle with pedals. Adding rear suspension is also possible.

Get a steel frame like that to start with, then do the welding to modify it to take a moped size tire, stiffen it, and lengthen it enough so it won't want to stand on it's front wheel at 40 mph quite so easy. Yes, you'll wheelie off the line fine, but just think again about the other end of the blast, the 40 mph stoppie.

Go measure a motorcycle, that's the length you need for a homemade motorcycle, not a short wheelbase MTB with no rear shocks. .

Finished cargo mixte..jpg
 
That's a lot of power, I think you could ride a regular bike frame but things will break. You want full suspension for sure, my last bike was front suspension only and did 44 mph top (70kph) and it was a very rough ride even standing. I think bike tires are ok if you're careful, especially if you keep them at high pressure for higher speed.

It's a good build though, don't let people stop you from trying it. I understand the concern with police and you're right, anything but bicycle wheels would be a complete no-go.
 
Hello Fabien, @20C the 25R will reach 95.2(℃) and 106(℃) @25C.
Also don't forget that is a 3.27V and 3.18V voltage sag, then the maximum output power (before controler/motor/transmission loss) will be around 7650W.
Then your 20s6p pack will last 150 cycles if it doesn't burn before or if you dont crash yourself with such a bad frame and whells.

Good luck frenchie !

Edit: I think you don't need a BMS as your pack is sentenced to death in a few months :lol:
 
10 Kw is where the fun begins... And when you start to consider full suspension, good brakes, better wheels, wider tires, geometry mods... All without adding too much weight, because weight kills power and your 10 Kw soon feels like 5. Then you start considering Watts per Pound, and optimize effective torque at the wheel. That is when the money begins to fly. :D
 
When I read all your answer I think I do a really really bad explanation of my needs!
I will try to explain how I will use it (I just ask you to trust me about my usage :wink: ).
A classic day for me will be :
- acceleration with 1000W maximum then cruising @ 45kph (PAS mode)
- I have 1 stop on my way to work -> big power to have some fun (full power for 5 seconds). I'll do that 2/3 times per battery cycle.
- when I reach 45kph -> cruising @ 45kph (PAS mode)

What I will not do :
- high speed @ 70kph all day long
- high power everytime

Please don't say it is a shitty usage or I will not use it this way. Just consider this is the way I'll use the bike :wink:

Wheazel said:
I think you should do either one of two things to improve your chances for a successful project.

1. Change the frame to something that will not be a rubbery snake when riding with 10kw and all the extra weight.
2. Ditch the idea of 10kw and reconsider what you actually need. What are you going to use 10kw for when riding 45km/h all day long?

I am riding my cargobike almost every day, and it can cruise just fine at 45km/h.
I use 600-1000W most of the time. and have the limit set around 2,5kw for heavy hills etc. This is a heavy bike with 20+kg of batteries, still leaves regular mopeds behind no problem.
Over 6000km in one year speaks for how reliable and usable it is, and its still far from perfect.

10kw on a regular bike will most likely be gimmicky, unsafe, and a pretty shit bike in the long run. After the initial hype, you will realize how lackluster the complete package is.
What I actually need? Almoast nothing, 1000W is more than enough.

You are speaking about extra wheight. But I'm 65kg. I'll add 20kg to the bike. I don't think it is worth than a fat guy riding a classic bike on hill down.

Why will it be shit bike on long run? With good setup it should react exactly the same as my old bike. With a good center of gravity it should be fine. Isn't it?

Chalo said:
I think you'll go faster than 100 kph unless you make some mistake in matching motor speed to road speed. If your battery voltage times the kV of your motor equals more than 130 kph at the wheel, then I think you'll get at least 100 on the road.

I think pedaling doesn't do very much at speeds over 50 kph. So you don't need gear ratios for higher speeds than that.

I think heavy bikes are less fun than light ones, and your performance target requires a heavy bike.

I recommend 2 ply Maxxis Hookworm tires if you can get them. That's a much stronger casing than necessary for a bicycle, maybe strong enough for what you have in mind.
72V on a 4T mxus 26" gives 70kph. You can check ebikes simu. Maybe it is not the best motor, I don't know that. I know a guy with the same motor/power and the motor goes great. Maybe it can do better, I don't know.
i'm looking for acceleration, not top speed. That's why I choose this one. I think 3T on a tiny rim would be better but I don't want it.

dogman dan said:
Well,, practice riding 40 mph on just the front wheel. That's what happens when you hit a bump you didn't see in time, with no rear shocks. It's really fun. 8)

This is no joke, it does happen. Ripping up a tire in 45 min happened to me too. This is one reason I got the welder, and started modifying frames.

Making them longer, and stiffer, and able to handle a smaller wheel without making the headset angle funny or having the pedals strike the ground. My bike looks funny, but no cop here thinks it's an illegal home made motorcycle with pedals. Adding rear suspension is also possible.

Get a steel frame like that to start with, then do the welding to modify it to take a moped size tire, stiffen it, and lengthen it enough so it won't want to stand on it's front wheel at 40 mph quite so easy. Yes, you'll wheelie off the line fine, but just think again about the other end of the blast, the 40 mph stoppie.

Go measure a motorcycle, that's the length you need for a homemade motorcycle, not a short wheelbase MTB with no rear shocks. .

That's good advice.

But this is for a 40mph/70kmh cruising speed right? Beacause I've done almost 10.000km at 45kmh with no problem.
I don't really care about max speed. The power is just for acceleration.


flat tire said:
That's a lot of power, I think you could ride a regular bike frame but things will break. You want full suspension for sure, my last bike was front suspension only and did 44 mph top (70kph) and it was a very rough ride even standing. I think bike tires are ok if you're careful, especially if you keep them at high pressure for higher speed.

It's a good build though, don't let people stop you from trying it. I understand the concern with police and you're right, anything but bicycle wheels would be a complete no-go.
Thank you :wink:

jpgey said:
Hello Fabien, @20C the 25R will reach 95.2(℃) and 106(℃) @25C.
Also don't forget that is a 3.27V and 3.18V voltage sag, then the maximum output power (before controler/motor/transmission loss) will be around 7650W.
Then your 20s6p pack will last 150 cycles if it doesn't burn before or if you dont crash yourself with such a bad frame and whells.

Good luck frenchie !

Edit: I think you don't need a BMS as your pack is sentenced to death in a few months :lol:
Yes you are absolutely right about the sag. That's my biggest concern!
20C is more than my needs. I need 10C (=25A). If you have the same number (t° and sag) for 10C I would really appreciate it.
I think it will be something like 3.3V. So 3.3*20*150 gives 10.000W (I know it does not work exactly this way). Will it be enough for power wheelie?

As I saif 10.000W is for only a few seconds. I hope for more than 150 cycles as I will cruise at 10A (700W).
 
I don't know anyone who has power and don't use it. Maybe you can restrain yourself at first, but sooner or later you will use all the power of your bike... And eventually want more. :wink:

Think for a minute how you will feel when you can accelerate the cars, and stay ahead in town. The feeling of freedom is a powerful drug.
 
Basically my road to work is a 10km straight line with one stop on the middle. I will not stop on the middle of the road just to use the power...
Just do the math. 0 to 45kph with 10.000W take what ? 5 seconds ? four time a day : 20 seconds full throttle => 55Wh. Let's say 100Wh if you want. Plus 800W to cruise at 45kph => 18wh/km x 20km. It is less than 500Wh. My battery is more than 1000wh...
If my maths are wrong, tell me. I'll be pleased to know.

Once again, I don't give a shit about top speed. My last bike was doing more than 50kph and I was never more than 45kph. So 45kph will be my cruising speed, period.
 
MadRhino said:
I don't know anyone who has power and don't use it. Maybe you can restrain yourself at first, but sooner or later you will use all the power of your bike... And eventually want more. :wink:

Think for a minute how you will feel when you can accelerate the cars, and stay ahead in town. The feeling of freedom is a powerful drug.

Thats the point.

But maybe hes the one in a million and can resist this.......i cant.
If my bike can do 10kw i will use it, its too much fun.
Driving with 800W when you can go 10kw, is like wanking when you have a hot girlfriend. :wink:

And again, i ripped my bicycle tires apart due to the torque......not the overall wear down.
So these 5 seconds are maybe enough.
At least for my old setup MXUS 4T 24" 120A.

But in the end i dont have to ride his bike, its his choice.
 
Wear issues aside I don't see the need for 10kw when you only need to go 45 kph. That's not fast at all. You could have a mid drive do that speed easily and have good acceleration due to gearing, way better weight distribution, huge reduction of unsprung weight...The only reason to get a hub motor in my opinion is if you want to sustain the fast speeds where you need high power to get around the wind resistance. If you only need to hit 45 kph a 1KW mid drive with some mild overclocking is a much better solution.

Also, try full suspension, you will be amazed.
 
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