I have two Kettler pedal cars I would like to convert to electric gokarts for my kids with a top speed of ~10mph. The drive train is a 1/2" bicycle chain with a 2" sprocket on the drive shaft and 10" wheels. I would like to use a foot controller for the acceleration and have a governor on the top speed within the circuit to "train" my kids to drive these safely. This could be mechanical on the pedal or electronic. I was imagining 24v rechargeable supply. As far as I can tell I need the foot controller, governor, motor, motor controller, and charger? What parts would you recommend?
What else am I missing?
To gear the pedal car for walking speed and to be able to climb steep hills it would need to have a low gear ratio. I checked online and found that Kettler Indianapolis Air pedal car has 4.00-4 tires. I checked online again and found that 4.00-4 tires have an 11.8 inch diameter so I based the calculations on that tire size. If the tires are a different diameter than 11.8 inches please let me know and I will recalculate the gear ratio.
I ran some gear ratio calculations and found that with our 23 Volt 350 watt gear motor and a 36 tooth sprocket on the axle the pedal car will have a top speed of 3.7 MPH. This is the top speed with no load so the actual top speed will be slightly lower.
Here is the gear ratio calculation.
I am not sure how many teeth the axle sprocket has on the Indianapolis Air pedal car however other Kettler pedal cars seem to have 11 tooth axle sprockets so chances are that the axle sprocket is not 36 teeth. Fortunately 36 teeth is a common size bicycle crank sprocket and we sell one for $7.95 which is our item # SPR-B36. Here is a photo of it.
This 36 tooth sprocket would need to be bolted or welded onto the original axle sprocket.
Our item # KIT-137 along with the 36 tooth sprocket item # SPR-B36 sounds like they might be the right combination of parts for your project. Here are links to these items.
If you would like any changes made to the kit, such as larger batteries, different throttle, etc. then please let us know.
Please let me know how it goes.
Hi Ed, The inline speed limiter will work with the pedal throttle and we can include it with the kit. I made a new kit that is without the charger port and includes the inline speed limiter. Here is a link to the modified kit:
If you think of any other changes that you would like made to the kit please let me know and I will update it to your specifications.
I ran a gear ratio calculation with a 12 tooth axle sprocket and here are the results.
The top speed would be around 11 miles per hour with a 12 tooth axle sprocket. At this speed the kart would have enough power to drive on flat ground and up slight inclines. However if you want it to go up moderate to steep inclines, or through sand or mud, then a larger axle sprocket would need to be installed to lower the gear ratio and top speed.
I found a 36 tooth sprocket for 1/2"x1/8" (#410) bicycle chain with 1/2" ID bore that we can special order. It hub is 3/4" wide and has a key way that is 1/8" deep and 1/4" wide and a setscrew to mount it onto the axle. We can also get this same sprocket in 27, 28, 40, 42, and 44 tooth versions. The cost is around $45 for these sprockets, however the sprocket is bolted onto its hub so if the sprocket wears out then a replacement sprocket without its hub would only cost around $25.
I can include this sprocket with a kit if you would like?
Please let us know if you have any questions.
After the kit order has been placed it will take our technician one to two working days to build the kit, and then around three working days for FedEx or UPS to deliver it. So you are looking at getting the kit in around a week after it has been ordered.
If you would like any changes made to the kit, or have any questions please let me know.