Electric moped cafe racer

[SlowCo]

I think you'll be better off to aim at 30mph/50km/h if you want to keep the motor cool enough and not trip the BMS when needing to go uphill. You might even downtune the shunt in the controller to lower the amp draw.

 

[vagosofron]

I think you'll be better off to aim at 30mph/50km/h if you want to keep the motor cool enough and not trip the BMS when needing to go uphill. You might even downtune the shunt in the controller to lower the amp draw.

Or choose another battery maybe? One that can give me more amps?

 

[SlowCo]

Yes the whole system needs to be compatible with each other. Basically the battery and its BMS determine how much power you can extract continuously and for a short peak. The 1800W continuous that the battery you linked to can provide should be enough to reach and maintain moped speeds of max. 50km/h. As Greece is part of the EU it probably will be mandatory to have the conversion to EV examined and approved to fall in the L1e class (mopeds with maximum cont. power of 4kW and max. speed of 50km/h). If you don't do that be aware you'll be riding an illegal motorized and thus uninsured vehicle. https://en.wikipedia.org/wiki/Vehicle_category

 

[vagosofron]

Yes the whole system needs to be compatible with each other. Basically the battery and its BMS determine how much power you can extract continuously and for a short peak. The 1800W continuous that the battery you linked to can provide should be enough to reach and maintain moped speeds of max. 50km/h. As Greece is part of the EU it probably will be mandatory to have the conversion to EV examined and approved to fall in the L1e class (mopeds with maximum cont. power of 4kW and max. speed of 50km/h). If you don't do that be aware you'll be riding an illegal motorized and thus uninsured vehicle. https://en.wikipedia.org/wiki/Vehicle_category

Ah ok i understand now. So even if i buy motor and controller that are capable of more power, they will be limited by the battery and bms?
I'm aware of the laws here, i will convert it legally.

 

[Dui ni shuo de dui]

Sorry to say it, but that's not really the nost appropriate frame to do an electric conversion, it will make things more complicated than you original plan to use a scooter.
First reason being that it will not be very easy to fit batteries in there.
Second reason being that I'm not sure the rear swingarm will be wide enough to fit a hub motor.
Third reason is that the brake system is terrible and you'll have a very hard time to upgrade it
Not saying that it is not doable, but it will not be easy.

So, first thing, check how wide the swingarm is and check if you can fit a QS hub motor in there. Inboard motors are much more complicated to install and I wouldn't recommend it for a first build, you need to keep things as simple as possible if you want to make it work, otherwise you'll hit major difficulties and will be discouraged.

Regarding the batteries, I think the only choice here will be to make some saddles and put the batteries there.

On first page, you mentionned reaching 60mph, and 50mils of autonomy.
I think you can easily achieve this with a 2-3000W hub motor, a 100-150A controller and a 72V, 30-50Ah battery.

3000Watts motor over 2000W motor if you want reliability
150A over 100A controller if you want acceleration (150A will be very powerfull, I'd say at least twice the power of the original gas engine)
50Ah over 30Ah battery if you want range. You should select your battery depending on what will be your final power, for instance, you can't go for a 30Ah battery if you're using a crazy powerful controller. But we'll help you on that later, don't worry.

As for speed, it usually depends on battery voltage (but also wheel size). I'd say 72V should be able to reach 60mph with that wheel size, but if you want to be absolutely sure, then buy a controller capable of flux weakening, this way you'll be able to get a nice speed bonus and you'll have the possibility to set whatever top speed you want (within reason, of course).

 

[vagosofron]

Sorry to say it, but that's not really the nost appropriate frame to do an electric conversion, it will make things more complicated than you original plan to use a scooter.
First reason being that it will not be very easy to fit batteries in there.
Second reason being that I'm not sure the rear swingarm will be wide enough to fit a hub motor.
Third reason is that the brake system is terrible and you'll have a very hard time to upgrade it
Not saying that it is not doable, but it will not be easy.

So, first thing, check how wide the swingarm is and check if you can fit a QS hub motor in there. Inboard motors are much more complicated to install and I wouldn't recommend it for a first build, you need to keep things as simple as possible if you want to make it work, otherwise you'll hit major difficulties and will be discouraged.

Regarding the batteries, I think the only choice here will be to make some saddles and put the batteries there.

On first page, you mentionned reaching 60mph, and 50mils of autonomy.
I think you can easily achieve this with a 2-3000W hub motor, a 100-150A controller and a 72V, 30-50Ah battery.

3000Watts motor over 2000W motor if you want reliability
150A over 100A controller if you want acceleration (150A will be very powerfull, I'd say at least twice the power of the original gas engine)
50Ah over 30Ah battery if you want range. You should select your battery depending on what will be your final power, for instance, you can't go for a 30Ah battery if you're using a crazy powerful controller. But we'll help you on that later, don't worry.

As for speed, it usually depends on battery voltage (but also wheel size). I'd say 72V should be able to reach 60mph with that wheel size, but if you want to be absolutely sure, then buy a controller capable of flux weakening, this way you'll be able to get a nice speed bonus and you'll have the possibility to set whatever top speed you want (within reason, of course).

That is the most helpfull answer i've read! Thank you.
At this time i don't need that kind of performance ( 45mph will do just fine).
I was going to modify the frame ( onyx style), with the tank in a horizontal position.
I am worried about the brakes, but i was thinking on upgrading into new ones ( used ofcourse) with diskbrakes.
A hub motor is my preference, but a middrive is cheaper. I have all the tools needed for frame modification, so that wont be a big issue. This could take long, but i will built it.

 

[Dui ni shuo de dui]

A hub motor is my preference, but a middrive is cheaper.

I'm a bit surprized by this, are you sure?
What motors did you compare?

If you have all the necessary tools and know how to use them then it's a very good start.
Next important point would be for you to figure out a ballpark figure of the budget you're planning to allocate on this, because many things will depend on it and it will help you to decide where you should make compromizes.

 

[vagosofron]

A hub motor is my preference, but a middrive is cheaper.

I'm a bit surprized by this, are you sure?
What motors did you compare?

If you have all the necessary tools and know how to use them then it's a very good start.
Next important point would be for you to figure out a ballpark figure of the budget you're planning to allocate on this, because many things will depend on it and it will help you to decide where you should make compromizes.

Unfortunately i can't find a hub motor in EU that can beat the price of a middrive kit i found that includes a 50a controller.
I'm also aware that this project will cost more than just a controller, motor, battery. If i can't built it correctly, i will not bult it at all.

 

[Dui ni shuo de dui]

Unfortunately i can't find a hub motor in EU that can beat the price of a middrive kit i found that includes a 50a controller.

50A is quite weak.
It won't be thrilling performance :wink:

What's your budget for this build?

 

[vagosofron]

Unfortunately i can't find a hub motor in EU that can beat the price of a middrive kit i found that includes a 50a controller.

50A is quite weak.
It won't be thrilling performance :wink:

What's your budget for this build?

I can spend 1000€ give or take, for all the parts. I already have the bike for the conversion.
So what is your opinion regarding the specs of the parts i need? I'm looking for a 45ish top speed and the range i'm not sure because my commute will be around 6-7 miles.
If i can't built this with the badget i have, then i might as well don't built it now and wait to raise more money.

 

[vagosofron]

Ok i just decided ( and the wife) that we will convert our 50cc scooter into electric. We are not looking for crazy performance, but something along the original engines capabilities ( more power is welcome though).
This scooter has 13 inch wheels. Is a mid drive suitable for a conversion like this? Will the rear sprocket fit in that wheel ( sizewise i mean)?
I will obviously get rid of all unnecessary parts to make it lighter.
What do you think? 48v, 60v or 72v? Like i mentioned above, i can only buy from eu sellers. Thanks in advance.