I am converting a Manco Critter single seat kart from gas to electric for my grandsons (6 -7 yrs old). As it will be used as mostly a street kart I have removed the roll cage and associated tubing to make it as light as possible. Max speed of 20 mph but also needs to have the ability to adjust the speed to a lower setting if need be. The diameter of the rear tires is 14.5" with a 60T sprocket (#35 chain). It is left hand drive so the motor needs to rotate in the CCW direction when going forward. It needs to have reverse also. The cart will be driven on neighborhood streets, mostly flat with some hills. I would like to have a ride time in the 1 hour range. By the way, the dads might be tempted to ride also.
What would be your suggestion as far as voltage, battery AH, motor size and controller? Do you have a ready made kit?
Since it needs a motor that rotates CCW when going forward I recommend our MOT-481600BLDC-MB 48 Volt 1600 Watt brushless motor and SPD-481500BLDC controller. This controller has a built-in reverse function and is programmable for the motor to spin CW or CCW as its forward direction. This controller also has a function to connect a switch to it for slow-normal-fast top speed selection and if that does not provide enough range of top speed control then we have an infinitely variable top speed adjustment limiter which can go between the throttle and controller.
I ran a gear ratio calculation using this motor and the gear ratio is too high with a 60 tooth axle sprocket, however, with an 80 tooth or larger axle sprocket the gear ratio is acceptable for the motor. Here are some of the results:
With 80 tooth sprocket: 29.21 MPH
With 90 tooth sprocket: 25.96 MPH
With 100 tooth sprocket: 23.37 MPH
We carry all of the sprockets listed above along with sprocket-to-axle adapters for go-karts.
For a 1 hour ride time at full throttle, our ride time calculator is showing four 12V 26Ah batteries on flat ground, and four 12V 35Ah batteries on flat ground with some hills. Our calculator tends to be on the conservative side so the actual ride time may be more than it estimates especially if the rider does not weigh very much or the hills are infrequent or gently sloped.
As far as ready made kits go I checked and we do not have anything that is exactly what you need, however, we can make a new kit or modify an existing kit specifically for your project, The closest kit I could find is our KIT-481600-12 which we could easily make a new version of with a foot throttle and larger batteries.
Please let us know your thoughts and we can take it from there.
Okay, that sounds good. We can make a new version of the KIT-481600-12 kit with only the parts that you need. For the batteries, what Ah rating would you like the kit to have?
We have got the kit finished. It is our kit # KIT-481600-31. Here is the link to it: https://cart.electricscooterparts.com/ProductDetails.asp?ProductCode=KIT-481600-31
Please let us know if we missed anything or if you would like any changes made to the kit.
For anyone else reading this who needs the same kit however with a foot throttle, we have the same kit available with a foot throttle as our kit # KIT-481600-30 at this link https://cart.electricscooterparts.com/ProductDetails.asp?ProductCode=KIT-481600-30 and we carry go-kart axle sprockets for #35 chain and axle sprocket hubs on our #35 Chain Sprockets page.
Please let us know if you have any questions.
I just checked and those controllers have been shipped to us with an estimated delivery date of Thursday June 28th. So we should have them back in stock in six days. As soon as they arrive I will let you know.
Ordered KIT-481600-31 today.
Thank you for your order.