Hugh-Jassman
1 kW
- Joined
- Jun 20, 2015
- Messages
- 407
I need a very slow motor to power my friends cargo bike. We don't want to build a large gear reduction. I figured that for a 3000 rpm motor it would take a 18:1 reduction (for about 13mph with a 26inch tire) a 3:1 reduction would be much easier. But A 9:1 ratio would be good for a 26” tire if the motor runs at about 1500rpm at the power needed.
Can anyone recommend a very slow but high enough power motor?
Is the Mac 12t the only option?
On this page https://em3ev.com/shop/mac-5001000w-motor it says the 8t motor is good for 50kph at 48v on a 26inch rim (I think they mean OD of tire) but this does not tell me what I need to know.
ok down on the page I found the rpms out put 12 turn standard motor 12 turn low speed extra torque motor – 200rpm loaded at 36V I think that may do it.......
As a guideline you can expect approximately the following real world speeds for the above windings on 12S LiFePO4 battery pack (approximately 38V under load) in a 26″ rim on the flat, no pedaling with a rider plus bike weight of approximately 130kg total (286pounds):
6T – 45kph (28mph)
8T – 39kph (24mph)
10T – 32kph (20mph)
12T – 25kph (15mph)
I see that grin tech's motorsimulator has been rigged to not calculate 250kg or 551lbs..... so what can I do now.
I definatly do not want to use a geared hub motor.
here is a sprocket to speed caculator https://www.electricscooterparts.com/motorwheelgearratio.html#gear-ratio-guide
Now I need a photo of the right way to rig it.
Can anyone recommend a very slow but high enough power motor?
Is the Mac 12t the only option?
On this page https://em3ev.com/shop/mac-5001000w-motor it says the 8t motor is good for 50kph at 48v on a 26inch rim (I think they mean OD of tire) but this does not tell me what I need to know.
ok down on the page I found the rpms out put 12 turn standard motor 12 turn low speed extra torque motor – 200rpm loaded at 36V I think that may do it.......
As a guideline you can expect approximately the following real world speeds for the above windings on 12S LiFePO4 battery pack (approximately 38V under load) in a 26″ rim on the flat, no pedaling with a rider plus bike weight of approximately 130kg total (286pounds):
6T – 45kph (28mph)
8T – 39kph (24mph)
10T – 32kph (20mph)
12T – 25kph (15mph)
I see that grin tech's motorsimulator has been rigged to not calculate 250kg or 551lbs..... so what can I do now.
I definatly do not want to use a geared hub motor.
here is a sprocket to speed caculator https://www.electricscooterparts.com/motorwheelgearratio.html#gear-ratio-guide
Now I need a photo of the right way to rig it.